Note: Descriptions are shown in the official language in which they were submitted.
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
METHODS FOR MONITORING BACTERIA USING OPTICOANALYTICAL
DEVICES
BACKGROUND
[0001]
The present invention generally relates to methods for the monitoring
of fluids in or near real-time, and, more specifically, to methods for
monitoring fluids prior
to, during or after their introduction into a subterranean formation and/or to
methods for
monitoring produced fluids from a subterranean formation.
[0002]
When conducting operations within a subterranean formation, it can be
important to precisely know the characteristics of a fluid or other component
present in or
being introduced into the formation. Typically, the analysis of fluids and
other components
being introduced into a subterranean formation has been conducted off-line
using laboratory
analyses (e.g., spectroscopic and/or wet chemical methods). These analyses can
be
conducted on fluid samples being introduced into the subterranean formation or
on flow back
fluid samples being produced from the subterranean formation after a treatment
operation has
occurred. Depending on the analysis needed, such an approach can take hours to
days to
complete, and even in the best case scenario, a job can often be completed
prior to the
analysis being obtained. Furthermore, off-line laboratory analyses can
sometimes be difficult
to perform, require extensive sample preparation and present hazards to
personnel performing
the analyses. Bacterial analyses can particularly take a long time to
complete, since culturing
of a bacterial sample is usually needed to obtain satisfactory results.
[0003]
Although off-line, retrospective analyses can be satisfactory in certain
cases, they do not generally allow real-time or near real-time, proactive
control of a
subterranean operation to take place. That is, off-line, retrospective
analyses do not allow
active control of a subterranean operation to take place, at least without
significant process
disruption occurring while awaiting the results of an analysis. In many
subterranean
operations, the lack of real-time or near real-time, proactive control can be
exceedingly
detrimental to the intended outcome of the subterranean operation. For
example, if an
incorrect treatment fluid is introduced into a subterranean formation, or if a
correct treatment
fluid having a desired composition but at least one undesired characteristic
(e.g., the wrong
concentration of a desired component, the wrong viscosity, the wrong pH, an
interfering
impurity, a wrong sag potential, the wrong kind or concentration of proppant
particulates,
bacterial contamination and/or the like) is introduced into a subterranean
formation, the
subterranean operation can produce an ineffective outcome or a less effective
outcome than
desired. Worse yet, if an incorrect treatment fluid or a treatment fluid
having an undesired
1
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
characteristic is introduced into the subterranean formation, damage to the
formation can
occur in some cases. Such damage can sometimes result in the abandonment of a
wellbore
penetrating the subterranean formation, or a remediation operation can
sometimes be needed
to at least partially repair the damage. In either case, the consequences of
introducing the
wrong treatment fluid into a subterranean formation can have serious financial
implications
and result in considerable production delays.
[0004]
Off-line, retrospective analyses can also be unsatisfactory for
determining the true suitability of a treatment fluid for performing a
treatment operation or
for evaluating the true effectiveness of a treatment operation. Specifically,
once removed
from their subterranean environment and transported to a laboratory, the
characteristics of a
treatment fluid sample can change, thereby making the properties of the sample
non-
indicative of the true effect produced by the treatment fluid in the
subterranean formation.
Similar issues also can be encountered in the analysis of treatment fluids
before they are
introduced into a subterranean formation. That is, the properties of the
treatment fluid can
change during the lag time between collection and analysis. In such cases, a
treatment fluid
that appears unsuitable for subterranean use based upon its laboratory
analysis could have
been suitable if introduced into the subterranean formation at an earlier
time. The converse
can also be true. Factors that can alter the characteristics of a treatment
fluid during the lag
time between collection and analysis can include, for example, scaling,
reaction of various
components in the fluid with one another, reaction of various components in
the fluid with
components of the surrounding environment, simple chemical degradation, and
bacterial
growth.
[0005]
In addition, the monitoring of source materials that are being used in
the formation of a treatment fluid can also be of interest. For example, if an
incorrect source
material or the wrong quality and/or quantity of a source material is used to
form a treatment
fluid, it is highly likely that the treatment fluid will have an undesired
characteristic. In this
regard, monitoring of a source material can also be an important quality
control feature in the
formation of a treatment fluid.
[0006]
In addition to monitoring the characteristics of treatment fluids that are
being introduced into a subterranean formation, the monitoring of fluids
produced from a
subterranean formation can also be of considerable interest. Produced fluids
of interest can
include both native formation fluids and flow back fluids produced after the
completion of a
treatment operation. As noted previously, the characteristics of a flow back
fluid can provide
2
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
an indication of the effectiveness of treatment operation, if analyzed
properly. In spite of the
wealth of chemical information that can be present in these fluids, it has
sometimes been
conventional in the art to simply dispose of produced formation water or flow
back fluids
resulting from a treatment operation. As an added concern, the significant
volumes of fluids
produced from a subterranean formation can present enormous waste disposal
issues,
particularly in view of increasingly strict environmental regulations
regarding the disposal of
produced water and other types of waste water. The inability to rapidly
analyze produced
fluids can make the recycling or disposal of these fluids exceedingly
problematic, since they
must be stored until analyses can be completed. As previously indicated, even
when an
analysis has been completed, there is no guarantee that the sample will remain
indicative of
the produced bulk fluid.
[0007]
More generally, the monitoring of fluids in or near real-time can be of
considerable interest in order to monitor how the fluids are changing with
time, thereby
serving as a quality control measure for processes in which fluids are used.
Specifically,
issues such as, for example, scaling, impurity buildup, bacterial growth and
the like can
impede processes in which fluids are used, and even damage process equipment
in certain
cases. For example, water streams used in cooling towers and like processes
can become
highly corrosive over time and become susceptible to scale formation and
bacterial growth.
Corrosion and scale formation can damage pipelines through which the water is
flowing and
potentially lead to system breakdowns. Similar issues can be encountered
for fluids
subjected to other types of environments.
[0008]
Spectroscopic techniques for measuring various characteristics of
materials are well known and are routinely used under laboratory conditions.
In some cases,
these spectroscopic techniques can be carried out without using an involved
sample
preparation. It is more common, however, to carry out various sample
preparation steps
before conducting the analysis. Reasons for conducting sample preparation
steps can include,
for example, removing interfering background materials from the analyte of
interest,
converting the analyte of interest into a chemical form that can be better
detected by the
chosen spectroscopic technique, and adding standards to improve the accuracy
of quantitative
measurements. Thus, there can be a delay in obtaining an analysis due to
sample preparation
time, even discounting the transit time of the sample to a laboratory.
Although spectroscopic
techniques can, at least in principle, be conducted at a job site or in a
process, the foregoing
concerns regarding sample preparation times can still apply. Furthermore, the
transitioning
3
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
of spectroscopic instruments from a laboratory into a field or process
environment can be
expensive and complex. Reasons for these issues can include, for example, the
need to
overcome inconsistent temperature, humidity and vibration encountered during
field or
process use. Furthermore, sample preparation, when required, can be difficult
under field
analysis conditions. The difficulty of performing sample preparation in the
field can be
especially problematic in the presence of interfering materials, which can
further complicate
conventional spectroscopic analyses. Quantitative spectroscopic measurements
can be
particularly challenging in both field and laboratory settings due to the need
for precision and
accuracy in sample preparation and spectral interpretation.
SUMMARY OF THE INVENTION
[0009]
The present invention generally relates to methods for the monitoring
of fluids in or near real-time, and, more specifically, to methods for
monitoring fluids prior
to, during or after their introduction into a subterranean formation and/or to
methods for
monitoring produced fluids from a subterranean formation.
[0010] In one
embodiment, the present invention provides a method
comprising: providing at least one source material; combining the at least one
source
material with a base fluid to form a treatment fluid; and monitoring a
characteristic of the
treatment fluid using a first opticoanalytical device that is in optical
communication with a
flow pathway for transporting the treatment fluid.
[0011] In one
embodiment, the present invention provides a method
comprising: preparing a treatment fluid; transporting the treatment fluid to a
job site;
introducing the treatment fluid into a subterranean formation at the job site;
monitoring a
characteristic of the treatment fluid at the job site using a first
opticoanalytical device that is
in optical communication with a flow pathway for transporting the treatment
fluid;
determining if the characteristic of the treatment fluid being monitored using
the first
opticoanalytical device makes the treatment fluid suitable for being
introduced into the
subterranean formation; and optionally, adjusting the characteristic of the
treatment fluid.
[0012]
In one embodiment, the present invention provides a method
comprising: forming a treatment fluid on-the-fly by adding at least one
component to a base
fluid stream; introducing the treatment fluid into a subterranean formation;
and monitoring a
characteristic of the treatment fluid using an opticoanalytical device while
the treatment fluid
is being introduced into the subterranean formation.
4
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
[0013]
In one embodiment, the present invention provides a method
comprising: providing at least one acid; combining the at least one acid with
a base fluid to
form an acidizing fluid; and monitoring a characteristic of the acidizing
fluid using a first
opticoanalytical device that is in optical communication with a flow pathway
for transporting
the acidizing fluid.
[0014]
In one embodiment, the present invention provides a method
comprising: providing an acidizing fluid comprising at least one acid;
introducing the
acidizing fluid into a subterranean formation; and monitoring a characteristic
of the acidizing
fluid using a first opticoanalytical device that is in optical communication
with a flow
pathway for transporting the acidizing fluid.
[0015]
In one embodiment, the present invention provides a method
comprising: forming an acidizing fluid on-the-fly by adding at least one acid
to a base fluid
stream; introducing the acidizing fluid into a subterranean formation; and
monitoring a
characteristic of the acidizing fluid using an opticoanalytical device while
the acidizing fluid
is being introduced into the subterranean formation.
[0016]
In one embodiment, the present invention provides a method
comprising: providing at least one fracturing fluid component; combining the
at least one
fracturing fluid component with a base fluid to form a fracturing fluid; and
monitoring a
characteristic of the fracturing fluid using a first opticoanalytical device
that is in optical
communication with a flow pathway for transporting the fracturing fluid.
[0017]
In one embodiment, the present invention provides a method
comprising: providing a fracturing fluid comprising at least one fracturing
fluid component;
introducing the fracturing fluid into a subterranean formation at a pressure
sufficient to create
or enhance at least one fracture therein; and monitoring a characteristic of
the fracturing fluid
using a first opticoanalytical device that is in optical communication with a
flow pathway for
transporting the fracturing fluid.
[0018]
In one embodiment, the present invention provides a method
comprising: forming a fracturing fluid on-the-fly by adding at least one
fracturing fluid
component to a base fluid stream; introducing the fracturing fluid into a
subterranean
formation at a pressure sufficient to create or enhance at least one fracture
therein; and
monitoring a characteristic of the fracturing fluid using an opticoanalytical
device while the
fracturing fluid is being introduced into the subterranean formation.
5
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
[0019]
In one embodiment, the present invention provides a method
comprising: providing a treatment fluid comprising a base fluid and at least
one additional
component; introducing the treatment fluid into a subterranean formation;
allowing the
treatment fluid to perform a treatment operation in the subterranean
formation; and
monitoring a characteristic of the treatment fluid or a formation fluid using
at least a first
opticoanalytical device within the subterranean formation, during a flow back
of the
treatment fluid produced from the subterranean formation, or both.
[0020]
In one embodiment, the present invention provides a method
comprising: providing a treatment fluid comprising a base fluid and at least
one additional
component; introducing the treatment fluid into a subterranean formation; and
monitoring a
characteristic of the treatment fluid using at least a first opticoanalytical
device that is in
optical communication with a flow pathway for transporting the treatment fluid
before the
treatment fluid is introduced into the subterranean formation.
[0021]
In one embodiment, the present invention provides a method
comprising: providing an acidizing fluid comprising a base fluid and at least
one acid;
introducing the acidizing fluid into a subterranean formation; allowing the
acidizing fluid to
perform an acidizing operation in the subterranean formation; and monitoring a
characteristic
of the acidizing fluid or a formation fluid using at least a first
opticoanalytical device within
the subterranean formation, during a flow back of the acidizing fluid produced
from the
subterranean formation, or both.
[0022]
In one embodiment, the present invention provides a method
comprising: providing an acidizing fluid comprising a base fluid and at least
one acid;
introducing the acidizing fluid into a subterranean formation; and monitoring
a characteristic
of the acidizing fluid using at least a first opticoanalytical device that is
in optical
communication with a flow pathway for transporting the acidizing fluid before
the acidizing
fluid is introduced into the subterranean formation.
[0023]
In one embodiment, the present invention provides a method
comprising: providing a fracturing fluid comprising a base fluid and at least
one fracturing
fluid component; introducing the fracturing fluid into a subterranean
formation at a pressure
sufficient to create or enhance at least one fracture therein, thereby
performing a fracturing
operation in the subterranean formation; and monitoring a characteristic of
the fracturing
fluid or a formation fluid using at least a first opticoanalytical device
within the subterranean
6
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
formation, during a flow back of the fracturing fluid produced from the
subterranean
formation, or both.
[0024]
In one embodiment, the present invention provides a method
comprising: providing a fracturing fluid comprising a base fluid and at least
one fracturing
fluid component; introducing the fracturing fluid into a subterranean
formation at a pressure
sufficient to create or enhance at least one fracture therein; and monitoring
a characteristic of
the fracturing fluid using at least a first opticoanalytical device that is in
optical
communication with a flow pathway for transporting the fracturing fluid before
the fracturing
fluid is introduced into the subterranean formation.
[0025] In one
embodiment, the present invention provides a method
comprising: providing water from a water source; monitoring a characteristic
of the water
using a first opticoanalytical device that is in optical communication with a
flow pathway for
transporting the water; and introducing the water into a subterranean
formation.
[0026]
In one embodiment, the present invention provides a method
comprising: producing water from a first subterranean formation, thereby
forming a
produced water; monitoring a characteristic of the produced water using a
first
opticoanalytical device that is in optical communication with a flow pathway
for transporting
the produced water; forming a treatment fluid comprising the produced water
and at least one
additional component; and introducing the treatment fluid into the first
subterranean
formation or a second subterranean formation.
[0027]
In one embodiment, the present invention provides a method
comprising: providing water from a water source; monitoring a characteristic
of the water
using a first opticoanalytical device that is in optical communication with a
flow pathway for
transporting the water; and treating the water so as to alter at least one
property thereof in
response to the characteristic of the water monitored using the first
opticoanalytical device.
[0028]
In one embodiment, the present invention provides a method
comprising: providing a fluid in a fluid stream; and monitoring a
characteristic of the fluid
using a first opticoanalytical device that is in optical communication with
the fluid in the
fluid stream.
[0029] In one
embodiment, the present invention provides a method
comprising: providing a fluid in a fluid stream; monitoring a characteristic
of the fluid using
a first opticoanalytical device that is in optical communication with the
fluid in the fluid
stream; determining if the characteristic of the fluid needs to be adjusted
based upon an
7
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
output from the first opticoanalytical device; performing an action on the
fluid in the fluid
stream so as to adjust the characteristic thereof; and after performing the
action on the fluid in
the fluid stream, monitoring the characteristic of the fluid using a second
opticoanalytical
device that is in optical communication with the fluid in the fluid stream.
[0030] In one
embodiment, the present invention provides a method
comprising: providing water in a fluid stream; performing an action on the
water in the fluid
stream so as to adjust a characteristic of the water; after performing the
action on the water in
the fluid stream, monitoring the characteristic of the water using an
opticoanalytical device
that is in optical communication with the water in the fluid stream; and
determining if the
characteristic of the water lies within a desired range.
[0031]
In one embodiment, the present invention provides a method
comprising: monitoring live bacteria in water using a first opticoanalytical
device that is in
optical communication with the water.
[0032]
In one embodiment, the present invention provides a method
comprising: providing a treatment fluid comprising a base fluid and at least
one additional
component; monitoring live bacteria in the treatment fluid using at least a
first
opticoanalytical device that is in optical communication with a flow pathway
for transporting
the treatment fluid; and introducing the treatment fluid into a subterranean
formation, after
monitoring the live bacteria therein.
[0033] In one
embodiment, the present invention provides a method
comprising: providing a treatment fluid comprising a base fluid and at least
one additional
component; introducing the treatment fluid into a subterranean formation; and
monitoring
live bacteria in the treatment fluid within the subterranean formation using
an
opticoanalytical device located therein.
[0034] The
features and advantages of the present invention will be readily
apparent to one having ordinary skill in the art upon a reading of the
description of the
preferred embodiments that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035]
The following figures are included to illustrate certain aspects of the
present invention, and should not be viewed as exclusive embodiments. The
subject matter
disclosed is capable of considerable modification, alteration, and equivalents
in form and
function, as will occur to one having ordinary skill in the art and having the
benefit of this
disclosure.
8
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
[0036]
FIGURE 1 shows a block diagram non-mechanistically illustrating
how an optical computing device separates electromagnetic radiation related to
a
characteristic or analyte of interest from other electromagnetic radiation.
[0037]
FIGURE 2 shows a non-limiting global schematic illustrating where
opticoanalytical devices (D) can be used in monitoring the process of forming
a fluid,
introducing a fluid into a subterranean formation, and producing a fluid from
a subterranean
formation.
[0038]
FIGURE 3 shows an illustrative schematic demonstrating how an
optical computing device can be implemented along a flow pathway used for
transporting a
fluid.
DETAILED DESCRIPTION
[0039]
The present invention generally relates to methods for the monitoring
of fluids in or near real-time, and, more specifically, to methods for
monitoring fluids prior
to, during or after their introduction into a subterranean formation and/or to
methods for
monitoring produced fluids from a subterranean formation.
[0040]
Various embodiments described herein utilize opticoanalytical devices
that can be utilized for the real-time or near real-time monitoring of fluids
that are ultimately
introduced into a subterranean formation. Likewise, these opticoanalytical
devices can be
used to monitor fluids that are produced from a subterranean formation
(including both flow
back fluids, formation fluids, and combinations thereof) or to monitor and
regulate fluids that
are used in various processes. These devices, which are described in more
detail herein, can
advantageously provide a measure of real-time or near real-time quality
control over the
introduction of fluids into a subterranean formation that cannot presently be
achieved with
either onsite analyses at a job site or more detailed analyses that take place
in a laboratory.
Further, these devices can advantageously provide timely information regarding
the
effectiveness of a treatment operation being performed in a subterranean
formation or the
monitoring of a fluid in a fluid stream, particularly while the fluid stream
is being modified in
some way. A significant advantage of these devices is that they can be
configured to
specifically detect and/or measure a particular component of a fluid, thereby
allowing
qualitative and/or quantitative analyses of the fluid to occur without sample
processing taking
place. The ability to perform quantitative analyses in real-time or near real-
time represents a
distinct advantage over time-consuming laboratory analyses, which can either
delay the start
of a subterranean operation or provide information too late to proactively
guide the
9
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
performance of a subterranean operation. In addition, the opticoanalytical
devices can be
capable of monitoring a treatment operation while a treatment fluid resides
within a
subterranean formation.
[0041]
The opticoanalytical devices utilized in the embodiments described
herein can advantageously allow at least some measure of proactive or
responsive control
over a treatment operation or other type of operation using a fluid to take
place. In this
regard, the capability of real-time or near real-time monitoring using the
opticoanalytical
devices can advantageously allow automation of a treatment operation to take
place through
an active feedback of information obtained using the opticoanalytical devices.
Specifically,
by coupling the opticoanalytical device to a processor configured for
manipulating analytical
data obtained therefrom (e.g., a computer, an artificial neural network,
and/or the like), a
treatment operation can be proactively controlled to allow a more effective
treatment
operation to take place. In some cases, the analytical data obtained from the
opticoanalytical
device can be manipulated to determine ways in which a fluid can be modified
to produce or
enhance a desired characteristic.
[0042]
In addition, real-time or near real-time monitoring using
opticoanalytical devices according to the embodiments described herein can
enable the
collection and archival of fluid information in conjunction with operational
information to
optimize subsequent subterranean operations in the same formation or in a
different
formation having similar chemical and physical characteristics. Significantly,
real-time or
near real-time monitoring using opticoanalytical devices can enhance the
capacity for remote
job execution.
[0043]
The opticoanalytical devices suitable for use in the present
embodiments can be deployed at any of a number of various points throughout a
system for
performing a treatment operation in a subterranean formation. Depending on the
point(s) at
which a treatment operation is monitored using the opticoanalytical device(s),
various types
of information about the treatment operation can be obtained. For example, in
some cases,
quality control information regarding source materials and treatment fluids
formed therefrom
can be obtained. In some cases, the change in a treatment fluid before and
after introduction
into a subterranean formation can be obtained. In addition, the
opticoanalytical devices of the
present embodiments can be used to monitor a treatment fluid of a formation
fluid while it is
downhole and subject to conditions of the subterranean environment, where it
can potentially
interact with the surface of a subterranean formation. Still further, the
opticoanalytical
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
devices can be used to monitor a fluid being produced from a subterranean
formation.
Characterization of the produced fluid can provide information about the
effectiveness of a
treatment operation that has taken place. In addition, characterization of the
produced fluid
can more readily allow disposal or recycling of the fluid to take place, if
that is desired. It is
to be recognized that the foregoing listing of information that can be
obtained using
opticoanalytical devices to monitor and/or control a treatment and/or
production process
should be considered illustrative in nature only. Depending on the locations
of the
opticoanalytical devices and the processing of information obtained therefrom,
other types of
information can be obtained as well.
[0044] Even
more generally, the opticoanalytical devices can be used to
monitor fluids and various changes thereto according to the embodiments
described herein.
In some cases, the opticoanalytical devices can be used to monitor changes to
a fluid that take
place over time, for example, in a pipeline or storage vessel. In some cases,
the
opticoanalytical devices can be used to monitor changes to a fluid that take
place as a result
of performing an action on the fluid (e.g., adding a component thereto,
removing a
component therefrom, or exposing the fluid to a condition that potentially
changes a
characteristic of the fluid in some way). Thus, the opticoanalytical devices
can be used to
monitor processes that take place upon fluids and in which fluids are used to
gain an
additional measure of process control.
[0045] As used
herein, the term "fluid" refers to a substance that is capable of
flowing, including particulate solids, liquids, and gases. In some
embodiments, the fluid can
be an aqueous fluid, including water. In some embodiments, the fluid can be a
non-aqueous
fluid, including organic compounds, more specifically, hydrocarbons, oil, a
refined
component of oil, petrochemical products, and the like. In some embodiments,
the fluid can
be a treatment fluid or a formation fluid. Fluids can include various flowable
mixtures of
solids, liquid and/or gases. Illustrative gases that can be considered fluids
according to the
present embodiments include, for example, air, nitrogen, carbon dioxide,
argon, methane and
other hydrocarbon gases, and/or the like.
[0046]
As used herein, the term "treatment fluid" refers to a fluid that is
placed in a subterranean formation in order to perform a desired function.
Treatment fluids
can be used in a variety of subterranean operations, including, but not
limited to, drilling
operations, production treatments, stimulation treatments, remedial
treatments, fluid diversion
operations, fracturing operations, and the like. As used herein, the terms
"treatment" and
11
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
"treating," as they refer to subterranean operations, refer to any
subterranean operation that
uses a fluid in conjunction with performing a desired function and/or
achieving a desired
purpose. The terms "treatment" and "treating," as used herein, do not imply
any particular
action by the fluid or any particular component thereof unless otherwise
specified. Treatment
fluids can include, for example, drilling fluids, fracturing fluids, acidizing
fluids,
conformance treatment fluids, diverting fluids, damage control fluids,
remediation fluids,
scale removal and inhibition fluids, chemical floods, sand control fluids, and
the like.
Generally, any treatment fluid and any treatment operation can be monitored
according to the
general techniques described herein.
[0047] As used
herein, the term "characteristic" refers to a chemical or
physical property of a substance. Illustrative characteristics of a substance
that can be
monitored according to the methods described herein can include, for example,
chemical
composition (identity and concentration, in total or of individual
components), impurity
content, pH, viscosity, density, ionic strength, total dissolved solids, salt
content, porosity,
opacity, bacteria content, and the like.
[0048]
As used herein, the term "electromagnetic radiation" refers to radio
waves, microwave radiation, infrared and near-infrared radiation, visible
light, ultraviolet
light, X-ray radiation and gamma ray radiation.
[0049]
As used herein, the term "in-process" refers to an event that takes place
while a treatment fluid is being introduced into a subterranean formation to
perform a
treatment operation, while the treatment operation is occurring, or while a
flow back fluid is
being produced from the subterranean formation as a result of the treatment
operation.
[0050]
As used herein, the term "flow back fluid" refers to a treatment fluid
that is produced from a subterranean formation subsequent to a treatment
operation.
[0051] As used
herein, the term "produced fluid" refers to a fluid that is
obtained from a subterranean formation. A produced fluid can include a flow
back fluid, a
native formation fluid present in the subterranean formation (including
formation water or
oil), or a combination thereof.
[0052]
As used herein, the term "formation fluid" refers to a fluid that is
natively present in a subterranean formation.
[0053]
As used herein, the term "in-line" refers to an event that takes place
during a process without the process being substantially disrupted.
12
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
[0054]
As used herein, the term "opticoanalytical device" refers to an optical
device that is operable to receive an input of electromagnetic radiation from
a substance and
produce an output of electromagnetic radiation from a processing element that
is changed in
some way so as to be readable by a detector, such that an output of the
detector can be
correlated to at least one characteristic of the substance. The output of
electromagnetic
radiation from the processing element can be reflected electromagnetic
radiation and/or
transmitted electromagnetic radiation, and whether reflected or transmitted
electromagnetic
radiation is analyzed by the detector will be a matter of routine experimental
design. In
addition, fluorescent emission of the substance can also be monitored by the
optical devices.
[0055] As used
herein, the term "flow pathway" refers to a route through
which a fluid is capable of being transported between two points. Flow
pathways between
two points need not necessarily be continuous. Illustrative flow pathways can
include,
various transportation means such as, for example, pipelines, hoses, tankers,
railway taffl(
cars, barges, ships, and the like. In addition, the term flow pathway should
not be construed
to mean that a fluid therein is flowing, rather that a fluid therein is
capable of being
transported through flowing.
[0056]
As used herein, the term "fluid stream" refers to quantity of fluid that
is flowing, for example, in a hose, pipeline or spray.
[0057]
As used herein, the term "kill ratio" refers to the number of live
bacteria present in a sample after a bactericidal treatment relative to the
number of live
bacteria present in a sample before a bactericidal treatment.
[0058]
As used herein, the term "live bacteria" refers to bacteria that are
capable of metabolic activity and normal reproduction. In some cases, live
bacteria can be
metabolically inactive and not in a state of normal reproduction due to
exposure to certain
environmental conditions (e.g., temperature or lack of an appropriate nutrient
source), while
still retaining the capability for normal metabolic activity and reproduction
upon exposure to
more favorable environmental conditions. In some embodiments, live bacteria
can be part of
a population of bacteria that has been substantially unaffected by a
bactericidal treatment.
More specifically, the term "live bacteria" refers to bacteria whose DNA or
RNA has not
been modified or degraded by a bactericidal treatment or whose cell wall
structure has not
been modified or degraded by a bactericidal treatment.
13
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
Opticoanalytical devices
[0059]
In general, opticoanalytical devices suitable for use in the present
embodiments can contain a processing element and a detector. In some
embodiments, the
opticoanalytical devices can be configured for specifically detecting and
analyzing a
characteristic or substance of interest. In some embodiments, the
opticoanalytical devices
can be configured to quantitatively measure a characteristic or a substance of
interest. In
other embodiments, the opticoanalytical devices can be general purpose optical
devices, with
post-acquisition processing (e.g., through computer means) being used to
specifically detect a
characteristic or substance of interest.
[0060] In some
embodiments, suitable opticoanalytical devices can be an
optical computing device. Suitable optical computing devices are described in
commonly
owned United States Patents 6,198,531; 6,529,276; 7,123,844; 7,834,999;
7,911,605, and
7,920,258, each of which is incorporated herein by reference in its entirety,
and United States
Patent Applications 12/094,460 (U.S. Patent Application Publication
2009/0219538),
12/094,465 (U.S. Patent Application Publication 2009/0219539), and 12/094,469
(U.S. Patent
Application Publication 2009/0073433), each of which is also incorporated
herein by
reference in its entirety. Accordingly, these optical computing devices will
only be described
in brief herein. Other types of optical computing devices can also be suitable
in alternative
embodiments, and the foregoing optical computing devices should not be
considered to be
limiting.
[0061]
Optical computing devices described in the foregoing patents and
patent applications combine the advantage of the power, precision and accuracy
associated
with laboratory spectrometers, while being extremely rugged and suitable for
field use.
Furthermore, the optical computing devices can perform calculations (analyses)
in real-time
or near real-time without the need for sample processing. In this regard, the
optical
computing devices can be specifically configured (trained) to detect and
analyze particular
characteristics and/or substances (analytes) of interest by using samples
having known
compositions and/or characteristics. As a result, interfering signals can be
discriminated from
those of interest in a sample by appropriate configuration of the optical
computing devices,
such that the optical computing devices can provide a rapid response regarding
the
characteristics of a substance based on the detected output. In some
embodiments, the
detected output can be converted into a voltage that is distinctive of the
magnitude of a
14
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
characteristic being monitored in the sample. The foregoing advantages and
others make the
optical computing devices particularly well suited for field and downhole use.
[0062]
Unlike conventional spectrometers, the optical computing devices can
be configured to detect not only the composition and concentrations of a
material or mixture
of materials, but they also can be configured to determine physical properties
and other
characteristics of the material as well, based on their analysis of the
electromagnetic radiation
received from the sample. For example, the optical computing devices can be
configured to
determine the concentration of an analyte and correlate the determined
concentration to a
characteristic of a substance by using suitable processing means. The optical
computing
devices can be configured to detect as many characteristics or analytes as
desired in a sample.
All that is required to accomplish the monitoring of multiple characteristics
or analytes is the
incorporation of suitable processing and detection means within the optical
computing device
for each characteristic or analyte. The properties of a substance can be a
combination of the
properties of the analytes therein (e.g., a linear combination). Accordingly,
the more
characteristics and analytes that are detected and analyzed using the optical
computing
device, the more accurately the properties of a substance can be determined.
[0063]
Fundamentally, optical computing devices utilize electromagnetic
radiation to perform calculations, as opposed to the hardwired circuits of
conventional
electronic processors. When electromagnetic radiation interacts with a
substance, unique
physical and chemical information about the substance are encoded in the
electromagnetic
radiation that is reflected from, transmitted through or radiated from the
sample. This
information is often referred to as the substance's spectral "fingerprint."
The optical
computing devices utilized herein are capable of extracting the information of
the spectral
fingerprint of multiple characteristics or analytes within a substance and
converting that
information into a detectable output regarding the overall properties of a
sample. That is,
through suitable configuration of the optical computing devices,
electromagnetic radiation
associated with characteristics or analytes of interest in a substance can be
separated from
electromagnetic radiation associated with all other components of a sample in
order to
estimate the sample's properties in real-time or near real-time.
[0064] In
various embodiments, the optical computing devices can contain an
integrated computational element (ICE) that is capable of separating
electromagnetic
radiation related to the characteristic or analyte of interest from
electromagnetic radiation
related to other components of a sample. Further details regarding how the
optical computing
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
devices can separate and process electromagnetic radiation related to the
characteristic or
analyte of interest are described in United States Patent 7,920,258,
previously incorporated
herein by reference. FIGURE 1 shows a block diagram non-mechanistically
illustrating how
an optical computing device separates electromagnetic radiation related to a
characteristic or
analyte of interest from other electromagnetic radiation. As shown in FIGURE
1, after being
illuminated with incident electromagnetic radiation, sample 100 containing an
analyte of
interest produces an output of electromagnetic radiation, some of which is
electromagnetic
radiation 101 from the characteristic or analyte of interest and some of which
is background
electromagnetic radiation 101' from other components of sample 100.
Electromagnetic
radiation 101 and 101' impinge upon optical computing device 102, which
contains ICE 103
therein. ICE 103 separates electromagnetic radiation 101 from electromagnetic
radiation
101'. Transmitted electromagnetic radiation 105, which is related to the
characteristic or
analyte of interest, is carried to detector 106 for analysis and
quantification (e.g., to produce
an output of the characteristics of sample 100). Reflected electromagnetic
radiation 104,
which is related to other components of sample 100, can be directed away from
detector 106.
In alternative configurations of optical computing device 102, reflected
electromagnetic
radiation 104 can be related to the analyte of interest, and transmitted
electromagnetic
radiation 105 can be related to other components of the sample. In some
embodiments, a
second detector (not shown) can be present that detects the electromagnetic
radiation
reflected from ICE 103. Without limitation, the output of the second detector
can be used to
normalize the output of detector 106. In some embodiments, a beam splitter can
be employed
(not shown) to split the two optical beams, and the transmitted or reflected
electromagnetic
radiation can then directed to ICE 103. That is, in such embodiments, ICE 103
does not
function as the beam splitter, as depicted in FIGURE 1, and the transmitted or
reflected
electromagnetic radiation simply passes through ICE 103, being computationally
processed
therein, before travelling to detector 106.
[0065]
Suitable ICE components are described in commonly owned United
States Patents 6,198,531; 6,529276; and 7,911,605, each previously
incorporated herein by
reference, and in Myrick, et at. "Spectral tolerance determination for
multivariate optical
element design," FRESENUIS' JOURNAL OF ANALYTICAL CHEMISTRY, 369:2001, pp. 351-
355,
which is also incorporated herein by reference in its entirety. In general, an
ICE comprises an
optical element whose transmissive, reflective, and/or absorptive properties
are suitable for
detection of a characteristic or analyte of interest. The optical element can
contain a specific
16
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
material for accomplishing this purpose (e.g., silicon, germanium, water, or
other material of
interest). In some embodiments, the material can be doped or two or more
materials can be
combined in a manner to result in the desired optical characteristic. For
example, deposited
layers of materials that have appropriate concentrations and thicknesses can
be used to create
an ICE having suitable properties. In addition to solids, an ICE can also
contain liquids
and/or gases, optionally in combination with solids, in order to produce a
desired optical
characteristic. In the case of gases and liquids, the ICE can contain a vessel
which houses the
gases or liquids. In addition to the foregoing, an ICE can also comprise
holographic optical
elements, gratings, and/or acousto-optic elements, for example, that can
create transmission,
reflection, and/or absorptive properties of interest. Other types of ICE
components can also
be suitable in alternative embodiments, and the foregoing ICE components
should not be
considered to be limiting.
[0066]
Once ICE 103 has separated electromagnetic radiation 101 related to
the sample, optical computing device 102 can provide an optical signal (e.g.,
transmitted
electromagnetic radiation 105), which is related to the amount (e.g.,
concentration) of the
characteristic or analyte of interest. In some embodiments, the relation
between the optical
signal and the concentration can be a direct proportion. Detector 106 can be
configured to
detect transmitted electromagnetic radiation 105 and produce a voltage output
in an
embodiment, which is related to the amount of the characteristic or analyte of
interest.
[0067] When
monitoring more than one analyte at a time, various
configurations for multiple ICEs can be used, where each ICE has been
configured to detect a
particular characteristic or analyte of interest. In some embodiments, the
characteristic or
analyte can be analyzed sequentially using multiple ICEs that are presented to
a single beam
of electromagnetic radiation being reflected from or transmitted through a
sample. In some
embodiments, multiple ICEs can be located on a rotating disc, where the
individual ICEs are
only exposed to the beam of electromagnetic radiation for a short time.
Advantages of this
approach can include the ability to analyze multiple analytes using a single
optical computing
device and the opportunity to assay additional analytes simply by adding
additional ICEs to
the rotating disc. In various embodiments, the rotating disc can be turned at
a frequency of
about 10 RPM to about 30,000 RPM such that each analyte in a sample is
measured rapidly.
In some embodiments, these values can be averaged over an appropriate time
domain (e.g.,
about 1 millisecond to about 1 hour) to more accurately determine the sample
characteristics.
17
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
[0068]
In other embodiments, multiple optical computing devices can be
placed in parallel, where each optical computing device contains a unique ICE
that is
configured to detect a particular characteristic or analyte of interest. In
such embodiments, a
beam splitter can divert a portion of the electromagnetic radiation being
reflected by, emitted
from or transmitted through from the substance being analyzed into each
optical computing
device. Each optical computing device, in turn, can be coupled to a detector
or detector array
that is configured to detect and analyze an output of electromagnetic
radiation from the
optical computing device. Parallel configurations of optical computing devices
can be
particularly beneficial for applications that require low power inputs and/or
no moving parts.
[0069] In still
additional embodiments, multiple optical computing devices
can be placed in series, such that characteristics or analytes are measured
sequentially at
different locations and times. For example, in some embodiments, a
characteristic or analyte
can be measured in a first location using a first optical computing device,
and the
characteristic or analyte can be measured in a second location using a second
optical
computing device. In other embodiments, a first characteristic or analyte can
be measured in
a first location using a first optical computing device, and a second
characteristic or analyte
can be measured in a second location using a second optical computing device.
It should also
be recognized that any of the foregoing configurations for the optical
computing devices can
be used in combination with a series configuration in any of the present
embodiments. For
example, two optical computing devices having a rotating disc with a plurality
of ICEs
thereon can be placed in series for performing an analysis. Likewise, multiple
detection
stations, each containing optical computing devices in parallel, can be placed
in series for
performing an analysis.
[0070]
In alternative embodiments, a suitable opticoanalytical device can be a
spectrometer than has been ruggedized for field use. In various embodiments, a
suitable
spectrometer can include, for example, an infrared spectrometer, a UVNIS
spectrometer, a
Raman spectrometer, a microwave spectrometer, a fluorescence spectrometer, and
the like. It
is to be recognized that any of the preferred embodiments described herein
using an optical
computing device can be practiced in a like manner using a spectrometer, which
in most
cases has been ruggedized for field use. Techniques for ruggedizing the
foregoing
spectrometers will be dependent upon the field conditions in which
measurements are to take
place. Suitable ruggedization techniques will be apparent to one having
ordinary skill in the
art.
18
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
Automated Control and Remote Operation
[0071]
In some embodiments, the characteristics of the sample being analyzed
using the opticoanalytical device can be further processed computationally to
provide
additional characterization information about the substance being analyzed. In
some
embodiments, the identification and concentration of each analyte in a sample
can be used to
predict certain physical characteristics of the sample. For example, the bulk
characteristics of
a sample can be estimated by using a combination of the properties conferred
to the sample
by each analyte.
[0072]
In some embodiments, the concentration of each analyte or the
magnitude of each characteristic determined using the opticoanalytical devices
can be fed
into an algorithm operating under computer control. In some embodiments, this
algorithm
can make predictions on how the characteristics of the sample change if the
concentrations of
the analytes are changed relative to one another. In some embodiments, the
algorithm can be
linked to any step of the process for introducing a fluid or producing a fluid
from a
subterranean formation so as to change the characteristics of the fluid being
introduced to or
produced from a subterranean formation. In more general embodiments, the
algorithm can be
linked to a fluid being modified by some process, such that the fluid can be
monitored in-
process. In some embodiments, the algorithm can simply produce an output that
is readable
by an operator, and the operator can manually take appropriate action based
upon the output.
For example, if the algorithm determines that a component of a treatment fluid
being
introduced into a subterranean formation is out of range, the operator can
direct that
additional amounts of the component be added to the treatment fluid "on-the-
fly." In some
embodiments, onsite monitoring control by the operator can take place, while
in other
embodiments the operator can be offsite while controlling the process remotely
through
suitable communication means. In some embodiments, the algorithm can take
proactive
process control by automatically adjusting the characteristics of a treatment
fluid being
introduced into a subterranean formation or by halting the introduction of the
treatment fluid
in response to an out of range condition. For example, the algorithm can be
configured such
that if a component of interest is out of range, the amount of the component
can be
automatically increased or decreased in response. In some embodiments, the
response to the
out of range condition can involve the addition of a component that is not
already in the
treatment fluid. Likewise, if an inappropriate analyte is detected in a fluid
to be introduced
19
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
into a subterranean formation, the algorithm can determine a corrective action
(e.g., a
component to be added) to counteract or remove the characteristics conferred
by that analyte.
[0073]
In some embodiments, the algorithm can be part of an artificial neural
network. In some embodiments, the artificial neural network can use the
concentration of
each detected analyte in order to evaluate the characteristics of the sample
and predict how to
modify the sample in order to alter its properties in a desired way.
Illustrative but non-
limiting artificial neural networks are described in commonly owned United
States Patent
Application 11/986,763 (U.S. Patent Application Publication 2009/0182693),
which is
incorporated herein by reference in its entirety. For example, in a fluid
containing two
analytes of interest, a simple algorithm-based approach might detect that the
concentrations
of both analytes are out of range and adjust the composition of the fluid to
bring the analytes
back in range. However, an adjustment using an artificial neural network might
determine
that even though both analytes are out of range, the detected amounts, in
combination,
maintain a bulk characteristic of the fluid within a desired range. For
example, an algorithm-
based approach might determine that both a gelling agent concentration and
ionic strength are
out of their specified range for a fluid and mandate adjustment thereof;
however, an artificial
neural network might determine that the analyzed concentrations, in
combination, are
sufficient for maintaining a desired viscosity within the fluid and not direct
that adjustment be
made. Any combination of analytes and properties determined thereby lie within
the spirit
and scope of the present invention.
[0074]
It is to be recognized that an artificial neural network can be trained
using samples having known concentrations, compositions and properties. As the
training set
of information available to the artificial neural network becomes larger, the
neural network
can become more capable of accurately predicting the characteristics of a
sample having any
number of analytes present therein. Furthermore, with sufficient training, the
artificial neural
network can more accurately predict the characteristics of the sample, even in
the presence of
unknown analytes.
[0075]
It is to be recognized that in the various embodiments herein directed
to computer control and artificial neural networks that various blocks,
modules, elements,
components, methods and algorithms can be implemented through using computer
hardware,
software and combinations thereof. To illustrate this interchangeability of
hardware and
software, various illustrative blocks, modules, elements, components, methods
and
algorithms have been described generally in terms of their functionality.
Whether such
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
functionality is implemented as hardware or software will depend upon the
particular
application and any imposed design constraints. For at least this reason, it
is to be recognized
that one of ordinary skill in the art can implement the described
functionality in a variety of
ways for a particular application. Further, various components and blocks can
be arranged in
a different order or partitioned differently, for example, without departing
from the spirit and
scope of the embodiments expressly described.
[0076]
Computer hardware used to implement the various illustrative blocks,
modules, elements, components, methods and algorithms described herein can
include a
processor configured to execute one or more sequences of instructions,
programming or code
stored on a readable medium. The processor can be, for example, a general
purpose
microprocessor, a microcontroller, a digital signal processor, an application
specific
integrated circuit, a field programmable gate array, a programmable logic
device, a controller,
a state machine, a gated logic, discrete hardware components, an artificial
neural network or
any like suitable entity that can perform calculations or other manipulations
of data. In some
embodiments, computer hardware can further include elements such as, for
example, a
memory [e.g., random access memory (RAM), flash memory, read only memory
(ROM),
programmable read only memory (PROM), erasable PROM], registers, hard disks,
removable
disks, CD-ROMS, DVDs, or any other like suitable storage device.
[0077]
Executable sequences described herein can be implemented with one
or more sequences of code contained in a memory. In some embodiments, such
code can be
read into the memory from another machine-readable medium. Execution of the
sequences
of instructions contained in the memory can cause a processor to perform the
process steps
described herein. One or more processors in a multi-processing arrangement can
also be
employed to execute instruction sequences in the memory. In addition, hard-
wired circuitry
can be used in place of or in combination with software instructions to
implement various
embodiments described herein. Thus, the present embodiments are not limited to
any
specific combination of hardware and software.
[0078]
As used herein, a machine-readable medium will refer to any medium
that directly or indirectly provides instructions to a processor for
execution. A machine-
readable medium can take on many forms including, for example, non-volatile
media,
volatile media, and transmission media. Non-volatile media can include, for
example, optical
and magnetic disks. Volatile media can include, for example, dynamic memory.
Transmission media can include, for example, coaxial cables, wire, fiber
optics, and wires
21
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
that form a bus. Common forms of machine-readable media can include, for
example, floppy
disks, flexible disks, hard disks, magnetic tapes, other like magnetic media,
CD-ROMs,
DVDs, other like optical media, punch cards, paper tapes and like physical
media with
patterned holes, RAM, ROM, PROM, EPROM and flash EPROM.
[0079] In some
embodiments, the data collected using the opticoanalytical
devices can be archived along with data associated with operational parameters
being logged
at a job site. Evaluation of job performance can then be assessed and improved
for future
operations or such information can be used to design subsequent operations. In
addition, the
data and information can be communicated to a remote location by a
communication system
(e.g., satellite communication or wide area network communication) for further
analysis. The
communication system can also allow remote monitoring and operation of a
process to take
place. Automated control with a long-range communication system can further
facilitate the
performance of remote job operations. In particular, an artificial neural
network can be used
in some embodiments to facilitate the performance of remote job operations.
That is, remote
job operations can be conducted automatically in some embodiments. In other
embodiments,
however, remote job operations can occur under direct operator control, where
the operator is
not at the job site.
Location of the Opticoanalytical devices
[0080]
FIGURE 2 shows a non-limiting global schematic illustrating where
opticoanalytical devices (D), according to some embodiments of the present
invention, can be
used in monitoring the process of forming a fluid, introducing a fluid into a
subterranean
formation, and producing a fluid from a subterranean formation. It is to be
recognized that
the placement of opticoanalytical devices (D) depicted in FIGURE 2 should be
considered
illustrative in nature only for purposes of describing exemplary flow pathways
used in
forming and using fluids. As illustrated in FIGURE 2, the recovery of a flow
back fluid from
a subterranean formation is also included and considered to be a part of the
normal flow
pathways for forming and using a fluid, according to the present embodiments.
FIGURE 2
depicts potential monitoring locations along an illustrative flow pathway used
for forming a
fluid, where opticoanalytical devices (D) can be used to monitor various
characteristics of the
fluid. The monitoring locations are optional, and potentially additive, based
on the needs of a
user. Depending on the user's needs, an opticoanalytical (D) device at one
location can be
used, or opticoanalytical devices (D) at multiple locations can be used in any
combination
that is suitable to the user. For example, in a particular implementation of a
fluid formation,
22
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
introduction and production process, it is anticipated that only some of the
opticoanalytical
devices (D) will be present, but this will be a matter of operational design
for a user
depending upon the level of monitoring and information needed by the user.
Moreover,
opticoanalytical devices (D) can be at locations other than those depicted in
FIGURE 2,
and/or multiple opticoanalytical devices (D) can be placed at each depicted
location or others.
Without limitation, in some embodiments, the opticoanalytical devices (D) can
be used in at
least the following locations for monitoring a fluid being formed or
introduced into/produced
from a subterranean formation: at a supplier for a component of the fluid, on
a transport
means for the component, at a field site upon receipt of the component, at a
storage site for
the component, prior to and after combining one or more components to form a
treatment
fluid, during transport to and just before introduction into a subterranean
formation, within a
subterranean formation, and in the flow back fluid produced from the
subterranean formation.
Information that can be obtained at each of these locations, including process
control
resulting therefrom, will now be described in more detail.
Sourcing and Transport
[0081]
Referring to FIGURE 2, source material 200 can be monitored with an
opticoanalytical device (D1) prior or during transfer of a material to
transport means 201. In
some embodiments, opticoanalytical device (D1) can be located at the exit of a
container
housing source material 200. In other embodiments, opticoanalytical device
(D1) can be
located in a tank or storage vessel housing source material 200. In still
other embodiments,
opticoanalytical device (D1) can be located on transport means 201.
[0082]
Analyses that can be obtained at this stage include, without limitation,
the identity, concentration and purity of source material 200. That is,
opticoanalytical device
(D1) can be used as an initial quality check to ensure that the proper source
material has been
obtained. The source material on transport means 201 can then be transported
to storage
areas 202, 202' and 202" at a job site. Although FIGURE 2 has depicted a
single transport
means 201 delivering the same source material to storage areas 202, 202' and
202", it is to be
recognized that in most cases storage areas 202, 202' and 202" will each
contain different
materials that are transported by separate transport means 201. Further, it is
to be recognized
that any number of source materials can be utilized in the processes described
herein. That is,
the depiction of only three storage areas should not be considered limiting.
Prior to
depositing the source material in transport means 201 in any of storage areas
202, 202' or
202", opticoanalytical devices (D2 ¨ D4) can again be used to verify that the
source material
23
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
in transport means 201 has been delivered to the proper storage area and to
verify that the
source material has not degraded or otherwise changed during transport. It is
to be further
recognized that storage at a job site can optionally be omitted and the source
material on
transport means 201 can be directly combined with other materials to make a
treatment fluid.
Production of treatment fluids and monitoring thereof is discussed in greater
detail
hereinafter.
[0083]
In the field of subterranean operations, source material 200 is most
often obtained from a supplier at a location that is remote from a job site.
Accordingly,
transport means 201 is most typically a mobile carrier such as, for example, a
truck, a railway
car, boat or a barge. In FIGURE 2, the lines connecting source material 200,
transport means
201 and storage areas 202, 202' and 202" are broken to indicate that there is
no fixed
pathway therebetween. Although not typical in the field of subterranean
operations, transport
means 201 can alternately be a fixed pathway, such as a pipeline, for example,
in alternative
embodiments.
[0084] In
addition, once the source material is in storage areas 202, 202'
and/or 202", the source material can also be monitored with opticoanalytical
devices (not
shown) located within each storage area. The opticoanalytical devices within
storage areas
202, 202' and/or 202" can be used, for example, to determine if the source
material degrades
or is otherwise changed during storage. Further, analysis of the source
material while in
storage areas 202, 202' and/or 202" can be utilized by an operator to
determine the quantities
of source material to be used in a treatment fluid for subterranean
operations.
Combining Source Materials to Make a Treatment Fluid
[0085]
After obtaining one or more source materials at a job site, in some
embodiments, combining of the source materials to make a treatment fluid can
then take
place. It is to be understood that the term "combining" does not imply any
particular action
for combining (e.g., mixing or homogenizing) or degree of combining unless
otherwise
noted. Referring again to FIGURE 2, the source materials in storage areas 202,
202' and
202" can be combined with a base fluid in vessel 204 in order to form a
treatment fluid
therein. The source materials being transported from storage areas 202, 202'
and 202" can
again be monitored with opticoanalytical devices (D5 ¨ D7) prior to being
introduced into
vessel 204 to ensure that the proper source materials are present and that
they have not
degraded or otherwise changed during storage. Likewise, the characteristics of
the base fluid
from base fluid source 203 can be monitored using opticoanalytical device
(D8). As
24
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
discussed hereinafter, the base fluid can alternately be obtained from
recycled fluid stream
212, as discussed in more detail hereinbelow. In either case, monitoring of
the base fluid can
be important to ensure that a treatment fluid having the desired
characteristics is formed.
[0086]
It is to be recognized that vessel 204 can take on many different forms,
and the only requirement is that vessel 204 be suitable for combining the
source material(s)
with the base fluid. In some embodiments, vessel 204 be a mixer, blender or
homogenizer.
In some embodiments, vessel 204 can be a mixing tank. In some embodiments,
vessel 204
can be a pipe. In still other embodiments, vessel 204 can utilize an air mixer
to combine the
source materials with a base fluid. In some embodiments, vessel 204 can be a
reaction
chamber in which at least some of the source materials react with one another
upon forming
the treatment fluid.
[0087]
In various embodiments, the base fluid can be an aqueous base fluid
such as, for example, fresh water, acidified water, salt water, seawater,
brine, aqueous salt
solutions, surface water (i.e., streams, rivers, ponds and lakes), underground
water from an
aquifer, municipal water, municipal waste water, or produced water (e.g., from
recycled fluid
stream 212) from a subterranean formation. In alternative embodiments, the
base fluid can be
a non-aqueous base fluid such as, for example, a hydrocarbon base fluid. As
will be evident
to one having ordinary skill in the art, some treatment operations can be
ineffective if the
base fluid contains certain trace materials that prevent an effective
treatment operation from
occurring. For example, fracturing operations can be ineffective in the
presence of certain
ionic materials or some bacteria. Similarly, certain trace materials in a base
fluid can interact
in an undesired fashion with a source material. For example, if the base fluid
contains excess
sulfate ions, a precipitate can form in the presence of barium ions from a
source material.
According to the present embodiments, a base fluid containing
incompatibilities can be
identified before the formation of a treatment fluid, thereby conserving
valuable resources
that could otherwise be wasted in producing an ineffective and potentially
damaging
treatment fluid.
[0088]
It should again be noted that until vessel 204 is reached, the
characteristics of the source material(s) and the base fluid are monitored
prior to their being
combined with one another. Thus, incorrect source materials or out of range
characteristics
can be readily identified and addressed according to the embodiments described
herein. For
example, the composition of the treatment fluid can be adjusted in order to
address an out of
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
range condition. As previously described, monitoring and control of the
process can take
place automatically in order to address out of range conditions as soon as
possible.
[0089]
Continuing now with FIGURE 2, a treatment fluid formed in vessel
204 can be monitored after its formation to verify that it has the desired
characteristics for
performing a particular treatment operation.
Monitoring can be performed using
opticoanalytical device (D9) as the treatment fluid exits vessel 204.
Alternately,
opticoanalytical device (D9) can monitor the treatment fluid while in vessel
204. Thereafter,
the treatment fluid can be transported to pump 205 for introduction into
subterranean
formation 210. In the event that the treatment fluid has not been properly
combined in vessel
204 or if its characteristics are not those desired, the treatment fluid can
be diverted back into
vessel 204 rather than being introduced into subterranean formation 210
(diversion pathway
not shown). For example, a treatment fluid that was improperly mixed in vessel
204 might
have an incorrect composition or have an out of range viscosity that can be
remedied by
continued mixing. Optionally, one or more additional source materials or the
same source
materials added previously can be added to address the out of range condition.
Further
optionally, the treatment fluid can be disposed of if its characteristics
cannot be suitably
altered by addition of one or more additional substances or by continued
mixing. Although
not optimal, the disposal of a treatment fluid presents less serious economic
concerns than
haphazardly introducing the treatment fluid downhole where it can potentially
damage a
subterranean formation.
[0090]
In some embodiments, the treatment fluid can be formed in vessel 204
at a job site and directly transferred to pump 205 via a pipeline or other
type of fixed transfer
means. In some embodiments, the treatment fluid can be formed in vessel 204 at
a remote
site and transferred via mobile transfer means 206 where there is again not a
fixed connection
between vessel 204 and pump 205. The latter situation exists for offshore
subterranean
operations, wherein a treatment fluid can be formed onshore and transported
via boat or barge
to an offshore drilling platform for introduction downhole. As with transfer
means 201, the
treatment fluid can be monitored with opticoanalytical device (D10) as it is
loaded on mobile
transfer means 206 as a quality control check of the transfer process.
[0091] In the
case of a treatment fluid formed at a job site, the monitoring of
the treatment fluid prior to introduction into pump 205 is not typically of
great concern, since
the connection pathway thereto is usually fixed and the lag time between
formation of the
treatment fluid and downhole pumping is usually not lengthy. However, in the
event that the
26
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
treatment fluid is stored in vessel 204 or elsewhere prior to being introduced
downhole,
opticoanalytical device (D11) can be used to verify that the characteristics
of the treatment
fluid are still suitable for being introduced into the subterranean formation.
Opticoanalytical
device (D11) can be particularly useful for offshore subterranean operations.
In the case of
offshore subterranean operations, there can be a significant delay between the
formation of a
treatment fluid and downhole pumping, which can present the opportunity for
degradation of
the treatment fluid to occur. That is, a treatment fluid that was initially
suitable, as measured
by opticoanalytical device (D9), can change significantly in characteristics
by the time it
reaches an offshore site. In either case, the characteristics of the treatment
fluid can again be
monitored using opticoanalytical device (D11) as a final quality check before
the treatment
fluid is introduced into subterranean formation 210. Further, the
characteristics monitored
using opticoanalytical device (D11) can be used, in some embodiments, as a
baseline value to
help evaluate the effectiveness of a treatment operation, as discussed in more
detail
hereinafter.
[0092] If the
characteristics of the treatment fluid being introduced into
subterranean formation 210 are not in the desired range, in some embodiments,
the treatment
operation can be stopped or the characteristics of the treatment fluid can be
adjusted. In some
embodiments, the treatment fluid can be returned to vessel 204 to adjust the
characteristics of
the treatment fluid. In other embodiments, the treatment operation can be
continued, with
one or more additional components being added at the well head while the
treatment fluid is
being introduced into the subterranean formation, referred to herein as "on-
the-fly addition"
(process not shown).
Monitoring a Treatment Operation and a Flow Back Fluid Produced from a
Subterranean
Formation
[0093] Once
introduced into subterranean formation 210, in some
embodiments, one or more opticoanalytical devices (D12) can be used to monitor
the
treatment fluid while in the formation (e.g., in the well bore). Depending on
the location(s)
of the one or more opticoanalytical devices (D12) in subterranean formation
210 (e.g. in the
well bore), various types of information on the treatment operation can be
determined in real-
time or near real-time based upon fluid flow into or out of subterranean
formation 210. For
example, in some embodiments, the consumption of a substance in the treatment
fluid can be
monitored as the treatment fluid passes through various subterranean zones. In
other
embodiments, the flow pathway of the treatment fluid in the subterranean
formation can be
27
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
monitored as it passes various opticoanalytical devices (D12). Information
obtained from
opticoanalytical devices (D12) can not only be used to map the morphology of
the
subterranean formation but also to indicate whether the characteristics of the
treatment fluid
need to be changed in order to perform a more effective treatment. For
example, the
treatment fluid can be modified in order to address specific conditions that
are being
encountered downhole. In addition, in some embodiments, the treatment fluid
can be
monitored to ensure that its characteristics do not change in an undesirable
way when
introduced into the downhole environment. In the event that the treatment
fluid undesirably
changes upon being introduced downhole, the treatment fluid being introduced
into
subterranean formation 210 can be modified, as described above, or an
additional component
can be introduced separately within subterranean formation 210 in order to
address changes
in characteristics that occur during transit downhole. In some embodiments, a
treatment fluid
can be monitored downhole using opticoanalytical devices (D12) in order to
evaluate fluid
displacement and fluid diversion in the subterranean formation (e.g, the flow
pathway). In
such embodiments, real-time or near-real time data from opticoanalytical
devices (D12) can
be used to adjust the placement of the fluid using diverting agents and to
evaluate the
effectiveness of diverting agents. In some embodiments, the diverting agents
can be added to
the treatment fluid in response to the characteristics observed using
opticoanalytical devices
(D12). In other embodiments, fracture conductivity in the subterranean
formation can be
monitored using the opticoanalytical devices. In still other embodiments, a
formation fluid
can be monitored using opticoanalytical devices (D12).
[0094]
In addition to monitoring a treatment operation while the treatment
fluid is downhole, the flow back fluid produced from subterranean formation
210 can be
monitored using opticoanalytical device (D13) to provide information on the
treatment
operation. It is to be noted that monitoring the flow back fluid is where one
would
conventionally monitor the effectiveness of a treatment operation by
collecting aliquots of the
flow back fluid and conducting suitable laboratory analyses. In the present
embodiments, the
characteristics of the flow back fluid, as monitored using opticoanalytical
device (D13), can
be compared to the characteristics of treatment fluid being introduced into
subterranean
formation 210, as monitored using opticoanalytical device (D11). Any changes
in
characteristics, or lack thereof, can be indicative of the effectiveness of
the treatment
operation. For example, the total or partial consumption of a component in the
flow back
fluid (e.g., via chemical reactions in the subterranean formation) or the
formation of a new
28
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
substance in the flow back fluid can be indicative that at least some
treatment effect has
occurred. In some embodiments, a change in concentration of a component in the
treatment
fluid can be determined by monitoring the concentration in the flow back fluid
using
opticoanalytical device (D13) and the concentration of the component prior to
its introduction
into subterranean formation 210 using opticoanalytical device (D11) or another
upstream
opticoanalytical device. In some embodiments, the change in concentration can
be correlated
to an effectiveness of a treatment operation being performed in subterranean
formation 210.
[0095]
In some embodiments, the flow back fluid can comprise an aqueous
base fluid that is produced from subterranean formation 210 as a result of a
treatment
operation. In other embodiments, the flow back fluid can comprise a formation
water that is
produced from subterranean formation 210, particularly as a result of a
treatment operation.
In still other embodiments, the flow back fluid can also comprise a produced
hydrocarbon
from subterranean formation 210.
[0096]
After analysis, flow back fluid stream 211 can be directed in at least
two different ways. In some embodiments, the flow back fluid can be analyzed
and disposed
of In other embodiments, the flow back fluid can be analyzed and recycled.
[0097]
In some embodiments, if an initial analysis of the flow back fluid is
satisfactory using opticoanalytical device (D13), flow back fluid stream 211
can again be
optionally analyzed with opticoanalytical device (D14) and sent to disposal
stream 213,
provided that the characteristics of the flow back fluid remain within
acceptable disposal
parameters. If the initial analysis of the flow back fluid is not satisfactory
for disposal, as
determined by opticoanalytical device (D13), flow back fluid stream 211 can
have at least
one additional substance added thereto in order to adjust its characteristics
and make it
suitable for disposal. For example, a flow back fluid that is too acidic can
be at least partially
neutralized and analyzed again using opticoanalytical device (D14) prior to
disposal.
Alternatively, flow back fluid stream 211 can have a substance removed
therefrom in order to
adjust its characteristics and make it suitable for disposal. For example, a
metal contaminant
in flow back fluid stream 211 can be removed by ion exchange techniques in an
embodiment.
[0098]
Preferably, flow back fluid stream 211 can be reused in subsequent
subterranean operations such as, for example, as the base fluid of a treatment
fluid (e.g., a
fracturing fluid) or in a water flooding operation. In this regard, flow back
fluid stream 211
can be monitored using opticoanalytical device (D15) and modified, if
necessary, by adding
at least one substance thereto or removing at least one substance therefrom,
to produce
29
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
recycled fluid stream 212. After forming recycled fluid stream 212, it can be
monitored
using opticoanalytical device (D16) to verify that it has the characteristics
for forming
another treatment fluid in vessel 204. The treatment fluid formed using
recycled fluid stream
212 can be used in subterranean formation 210, in some embodiments, or
transported to
another subterranean formation in other embodiments. Alternately, recycled
fluid stream
212 can be monitored using opticoanalytical device (D17) to ensure that it is
suitable for
being reintroduced into subterranean formation 210 or another subterranean
formation. That
is, in some embodiments, the flow back fluid produced from a first
subterranean formation
can be used in a water flooding operation in a second subterranean formation.
It is to be
noted that if no modification of flow back fluid stream 211 is needed, then
formation of a
treatment fluid or introduction into a subterranean formation can take place
without further
modification occurring.
[0099]
In other embodiments, opticoanalytical device (D13) can be used to
assay a non-aqueous fluid being produced from a subterranean formation. For
example,
opticoanalytical device (D13) can be used to determine the composition of a
formation fluid
(e.g., a hydrocarbon) being produced from the subterranean formation.
Monitoring the Formation and Transport of a Treatment Fluid
[0100]
In various embodiments, the methods described herein can be used to
monitor and control the formation and transport of any type of treatment fluid
intended for
introduction into a subterranean formation. Regardless of the intended form or
function of
the treatment fluid, any desired characteristic of the treatment fluid can be
monitored
according to some embodiments described herein. Without limitation, treatment
fluids that
can be monitored during their formation and transport according to the present
embodiments
can include, for example, fracturing fluids, gravel packing fluids, acidizing
fluids,
conformance control fluids, gelled fluids, fluids comprising a relative
permeability modifier,
diverting fluids, fluids comprising a breaker, biocidal treatment fluids,
remediation fluids,
and the like. Although several specific examples of treatment fluids are set
forth hereinafter
in which the present methods can be used for monitoring, it is to be
recognized that these
examples are illustrative in nature only, and other types of treatment fluids
can be monitored
by one having ordinary skill in the art by employing like techniques.
[0101]
Illustrative substances that can be present in any of the treatment fluids
of the present invention can include, for example, acids, acid-generating
compounds, bases,
base-generating compounds, surfactants, scale inhibitors, corrosion
inhibitors, gelling agents,
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
crosslinking agents, anti-sludging agents, foaming agents, defoaming agents,
antifoam agents,
emulsifying agents, de-emulsifying agents, iron control agents, proppants or
other
particulates, gravel, particulate diverters, salts, fluid loss control
additives, gases, catalysts,
clay control agents, chelating agents, corrosion inhibitors, dispersants,
flocculants, scavengers
(e.g., H2S scavengers, CO2 scavengers or 02 scavengers), lubricants, breakers,
delayed
release breakers, friction reducers, bridging agents, viscosifiers, weighting
agents,
solubilizers, rheology control agents, viscosity modifiers, pH control agents
(e.g., buffers),
hydrate inhibitors, relative permeability modifiers, diverting agents,
consolidating agents,
fibrous materials, bactericides, tracers, probes, nanoparticles, and the like.
Combinations of
these substances can be used as well.
[0102]
In various embodiments, the treatment fluids used in practicing the
present invention also comprise a base fluid. In some embodiments, the base
fluid can be an
aqueous base fluid. In other embodiments, the base fluid can be a non-aqueous
base fluid,
such as a hydrocarbon.
[0103] In
various embodiments of the present invention, opticoanalytical
devices (e.g., optical computing devices and ruggedized spectrometers) can be
used to
monitor a treatment fluid during its formation and transport. Monitoring of
source materials
to be used in the treatment fluid, including water, can also be performed by
like techniques as
a quality control measure. In some embodiments, monitoring of the treatment
fluid and the
source material can occur "in-line" or "in-process" along a flow pathway for
transporting the
treatment fluid or source material without the transport being interrupted or
significantly
altered. For example, the embodiment shown in FIGURE 2 illustrates how an in-
line process
can be implemented in some embodiments, where the in-line monitoring can take
place using
at least one opticoanalytical device that is in optical communication with the
flow pathway.
As used herein, the term "in optical communication" refers to the condition of
an
opticoanalytical device being positioned along a flow pathway and the flow
pathway being
configured such that electromagnetic radiation reflected from, emitted by or
transmitted
through a fluid in the flow pathway is readable by the opticoanalytical
device. FIGURE 3,
which is discussed in more detail hereinbelow, shows an embodiment in which an
opticoanalytical device can be in optical communication with a flow pathway.
In some
embodiments, monitoring a fluid along a flow pathway (e.g., in a line) using
an
opticoanalytical device can take place while the fluid is flowing without the
fluid transport
process being interrupted. In other embodiments, monitoring a fluid along a
flow pathway
31
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
can take place without the fluid being transported. That is, the fluid
transport process can be
temporarily interrupted while monitoring takes place, with the fluid remaining
substantially
static in the flow pathway during monitoring. In still other embodiments, the
flow pathway
can be configured to divert a portion of the fluid away from its main
transport pathway,
where monitoring of the fluid can take place using the diverted portion. In
alternative
embodiments, the fluid from the diverted portion can be removed from the
system and
analyzed using an opticoanalytical device at a job site, where the
opticoanalytical device is
not used in-process. That is, in such embodiments, the fluid can be monitored
off-line using
a standalone opticoanalytical device.
[0104] Other
than when the opticoanalytical device is located in the
subterranean formation itself, the opticoanalytical device and the fluid that
it is monitoring
are not generally in direct physical contact with one another. Generally, the
opticoanalytical
device can be in optical communication with a fluid contained within a flow
pathway, as
described previously. However, in some alternative embodiments, the
opticoanalytical
device can be in direct physical contact with the fluid (e.g., in a tank or
within a flow
pathway). FIGURE 3 shows an illustrative schematic demonstrating how an
optical
computing device can be implemented along a flow pathway used for transporting
a fluid. As
shown in FIGURE 3, source 300 produces incident electromagnetic radiation 301,
which
interacts with fluid 310 within line 303 having window 304 defined therein.
Window 304 is
substantially transparent to incident electromagnetic radiation 301, allowing
it to interact with
fluid 310 therein. Interacted electromagnetic radiation 302 is changed by its
interaction with
fluid 310, and it exits though window 304', which is substantially transparent
to interacted
electromagnetic radiation 302, thereby allowing fluid 310 to be in optical
communication
with optical computing device 305. Some of interacted electromagnetic
radiation 302 is
related to a component of interest in the fluid, and the remaining interacted
electromagnetic
radiation 302 is due to interaction of the electromagnetic radiation with
background materials
or other components in the fluid. Interacted electromagnetic radiation 302
then enters optical
computing device 305 having ICE 306 therein. ICE 306 then separates interacted
electromagnetic radiation into components 307 and 308, related to the
component of interest
and other components, respectively. Electromagnetic radiation component 307
then interacts
with detector 309 to provide information on the component of interest in fluid
310. Further
details of the operation of the optical computing device were set forth
previously
32
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
hereinabove. In some embodiments, the output of detector 309 can be a voltage
signal, which
can be proportional to the concentration of the component of interest.
[0105]
In some embodiments, methods for analyzing the formation and
transport of a treatment fluid can comprise: providing at least one source
material;
combining the at least one source material with a base fluid to form a
treatment fluid; and
monitoring a characteristic of the treatment fluid using an opticoanalytical
device. In some
embodiments, the opticoanalytical device can be in optical communication with
a flow
pathway for transporting the treatment fluid (e.g., in-line monitoring). In
other embodiments,
monitoring a characteristic of the treatment fluid can take place in an off-
line manner.
[0106]
Characteristics of the treatment fluid or source material that can be
monitored can include both physical and chemical properties. Characteristics
of a treatment
fluid or a source material that can be monitored according to the present
methods can include,
without limitation, chemical composition identity, chemical composition
concentration,
chemical composition purity, viscosity, ionic strength, pH, total dissolved
solids, total
dissolved salt, density, and the like. In some embodiments, the characteristic
of the treatment
fluid can be determined directly from the output of a detector analyzing the
electromagnetic
radiation reflected from, emitted by or transmitted through the treatment
fluid. For example,
the identity and concentration of a component in a treatment fluid can be
directly determined
from a detector output (e.g., a voltage) based upon pre-established
calibration curves. In
other embodiments, the characteristic of the treatment fluid can be calculated
based upon a
concentration of one or more components in the treatment fluid, as determined
using the
opticoanalytical device. For example, a processing element can determine the
viscosity, pH,
sag potential, and/or any like physical property of the treatment fluid based
upon the content
of one or more components of the treatment fluid. Further, in some
embodiments, the
processing element can determine a characteristic of the treatment fluid based
upon a linear
combination of property contributions from each component of the treatment
fluid.
[0107]
In some embodiments, the processing element to determine a
characteristic of the treatment fluid can be an artificial neural network,
which can use training
set information from treatment fluids having known properties and compositions
in order to
estimate the characteristics of treatment fluids having unknown content prior
to analysis. By
determining a linear combination of property contributions based upon each
component of
the treatment fluid, a more accurate estimation of an unknown treatment
fluid's properties
can be determined than if the analysis was based upon a single component. That
is, the more
33
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
completely an artificial neural network is trained using treatment fluids
having known
properties, the more likely it is to better estimate the characteristics of an
unknown treatment
fluid.
[0108]
By employing the present methods, at least in some embodiments, a
measure of quality control during the formation of a treatment fluid can be
established.
Conventionally, treatment fluids are not rigorously analyzed during their
formation, or the
analysis often can take place after the treatment fluid has already been
introduced into a
subterranean formation, at which point the analysis is only of use in a
retrospective sense.
The present methods overcome this limitation in the art and others by
providing multiple
opportunities to identify and adjust the characteristics of a treatment fluid
before or during its
introduction into a subterranean formation.
[0109]
In some embodiments, a treatment fluid can be monitored immediately
after combining a base fluid and at least one source material to form the
treatment fluid. In
some embodiments, monitoring can take place in a vessel in which the treatment
fluid is
formed. In some embodiments, monitoring can take place as the treatment fluid
exits the
vessel in which the treatment fluid is formed. In some embodiments, monitoring
can take
place as the treatment fluid is formed "on-the-fly." In some embodiments, the
treatment fluid
can be monitored at one or more points as it is transported from the vessel to
be introduced
into a subterranean formation.
[0110] In some
embodiments, the present methods can further comprise
transporting the treatment fluid to a pump after forming the treatment fluid.
In some
embodiments, the methods can further comprise introducing the treatment fluid
into a
subterranean formation, for example, by using the pump. In some embodiments, a
characteristic of the treatment fluid can be monitored using an
opticoanalytical device that is
in optical communication with the fluid in a flow pathway to the subterranean
formation. In
such embodiments, the opticoanalytical device can be located at the pump or at
a location
near the pump, such that changes in the characteristics of the treatment fluid
between its
formation and subsequent introduction into a subterranean formation can be
evaluated. The
output from this opticoanalytical device can serve as the last line of defense
to prevent a
treatment fluid having an incorrect characteristic from being introduced into
a subterranean
formation. In some embodiments, transporting the treatment fluid to the pump
can take place
in a pipeline. In some embodiments, transporting the treatment fluid to the
pump can take
place via a mobile transport means such as a truck or railway car. In some
embodiments,
34
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
transporting the treatment fluid to the pump can take place by using a storage
vessel on a boat
or barge for transporting the treatment fluid to an offshore site.
[0111]
In some embodiments, the present methods can further comprise
determining if the characteristic of the treatment fluid being monitored makes
the treatment
fluid suitable for being introduced into a subterranean formation. In various
embodiments,
determining if the treatment fluid is suitable for being introduced into the
subterranean
formation can comprise determining if one or more components therein have an
out of range
concentration, determining if an unwanted component or other impurities are
present, and/or
determining if a physical characteristic of the treatment fluid is out of
range, for example.
Other criteria for determining the suitability of a treatment fluid to be
introduced into a
particular subterranean formation can be established by one having ordinary
skill in the art.
In some embodiments, determining if the characteristic makes the treatment
fluid suitable for
being introduced into the subterranean formation can take place automatically.
For example,
a computer or like processing element can be configured to determine if the
value of a
characteristic being monitored or estimated represents an out of range
condition. In some
embodiments, monitoring and determining the suitability of a treatment fluid
for being
introduced into a subterranean formation can take place via remote monitoring
and control.
[0112]
Upon determining that the treatment fluid is unsuitable, the present
methods can optionally further comprise adjusting a characteristic of the
treatment fluid. In
some embodiments, upon determining that the treatment fluid is unsuitable for
being
introduced into the subterranean formation, adjustment of a characteristic of
the treatment
fluid can take place under operator control. For example, an operator can
manually direct the
addition of one or more components to the treatment fluid to adjust its
composition and
properties. The characteristic of the treatment fluid can thereafter be re-
evaluated and the
suitability for introduction into a subterranean formation determined. In some
embodiments,
the operator can manually add the one or more components to the treatment
fluid. In other
embodiments, the operator can regulate an amount of one or more components
being added
to the treatment fluid from one or more source streams. In some embodiments,
adjustment of
a characteristic of the treatment fluid can take place automatically under
computer control.
For example, as described above, if a characteristic of the treatment fluid is
determined to be
out of range, a computer or like processing element can direct that at least
one component is
added to the treatment fluid to correct the out of range condition. In some
embodiments, an
additional amount of a component already in the treatment fluid can be added
to the treatment
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
fluid until the characteristic being monitored is back in an acceptable range.
In other
embodiments, at least one additional component can be added to the treatment
fluid in order
to bring the characteristic being monitored back into range. For example, in
the case of an
acidizing fluid, if the acid concentration is determined to be too high, a
quantity of a suitable
base can be added to neutralize some of the acid, or additional base fluid can
be added to the
treatment fluid in order to lessen the concentration of the acid. In
alternative embodiments, a
component can be removed from the treatment fluid in order to adjust its
characteristics. As
described previously, the impact of adding additional components to a
treatment fluid can
impact other characteristics other than those being directly addressed, and
when the
adjustment takes place automatically under computer control, at least an
estimation of the
impact on these other characteristics can be determined. That is, when a
characteristic of the
treatment fluid is adjusted automatically, the computer or like processing
element can
evaluate if the chosen adjustment is expected to impact other characteristics
of the treatment
fluid in an undesired manner and compensate for the adjustment of other
characteristics, if
needed.
[0113]
In some embodiments, an operator can adjust or reset a set point or a
set range for a characteristic of a fluid that is being automatically
controlled by computer. In
some embodiments, an operator can direct the adjustment of a characteristic or
change a set
point for automatic control by computer at the location of the treatment
operation or through
a communication system from a remote location.
[0114]
In some embodiments, combining the base fluid and at least one
component of the treatment fluid can occur at the well head by "on-the-fly"
addition of the at
least one component. That is, the treatment fluid can be formed at the well
head without
being transported from another location in such embodiments. Alternately, a
pre-made
treatment fluid can be modified at the well head by on-the-fly addition of at
least one
additional component or adjusting the concentration of an existing component
in some
embodiments. Advantages of on-the-fly addition can include, for example,
reduced volumes,
lower transportation costs, minimization of excess materials at a job site,
and less opportunity
for degradation of the treatment fluid. Such on-the-fly addition does not
allow the
characteristics of the treatment fluid to be assayed according to conventional
methodology
before the treatment fluid is introduced into the subterranean formation. This
represents a
particular difficulty with regard to control over a treatment operation, since
it can often be
difficult to precisely determine how much of a component to add in order to
produce a
36
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
treatment fluid having a desired characteristic. The same can hold true even
with treatment
fluids that are pre-formulated before being transported to a job site.
However, these
difficulties in the art can be overcome through use of the methods of the
present invention by
using opticoanalytical devices for monitoring the treatment fluid during its
formation and
introduction into a subterranean formation.
[0115]
In some embodiments, the present methods can further comprise
monitoring a characteristic of at least one source material being used to form
a treatment fluid
by using an opticoanalytical device. In some embodiments, the opticoanalytical
device can
be in optical communication with a flow pathway for transporting the at least
one source
material. In some embodiments, the opticoanalytical device can be in a taffl(
or other storage
vessel housing the source material. In other embodiments, monitoring of the at
least one
source material can take place off-line. As discussed above, monitoring of the
source
material can serve as an additional quality check during the formation of a
treatment fluid.
[0116]
In some embodiments, methods of the present invention can comprise:
preparing a treatment fluid; transporting the treatment fluid to a job site;
introducing the
treatment fluid into a subterranean formation at the job site; monitoring a
characteristic of the
treatment fluid at the job site using an opticoanalytical device; determining
if the
characteristic of the treatment fluid being monitored using the
opticoanalytical device makes
the treatment fluid suitable for being introduced into the subterranean
formation; and
optionally, if the treatment fluid is unsuitable, adjusting the characteristic
of the treatment
fluid. In some embodiments, the opticoanalytical device can be in optical
communication
with a flow pathway for transporting the treatment fluid. In other
embodiments, monitoring
using the opticoanalytical device can take place off-line.
[0117]
In some embodiments, methods of the present invention can comprise:
providing a treatment fluid that comprises a base fluid and at least one
additional component;
introducing the treatment fluid into a subterranean formation; and monitoring
a characteristic
of the treatment fluid using at least a first opticoanalytical device. In some
embodiments, the
opticoanalytical device can be in optical communication with a flow pathway
for transporting
the treatment fluid before the treatment fluid is introduced into the
subterranean formation.
In other embodiments, monitoring using the opticoanalytical device can take
place off-line
before the treatment fluid is introduced into the subterranean formation.
[0118]
In some embodiments, methods of the present invention can comprise:
forming a treatment fluid on-the-fly by adding at least one component to a
base fluid stream;
37
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
introducing the treatment fluid into a subterranean formation; and monitoring
a characteristic
of the treatment fluid while it is being introduced into the subterranean
formation using an
opticoanalytical device. In some embodiments, the methods can further
comprise:
determining if the characteristic of the treatment fluid being monitored using
the
opticoanalytical device makes the treatment fluid suitable for being
introduced into the
subterranean formation, and optionally, if the treatment fluid is unsuitable,
adjusting the
characteristic of the treatment fluid.
Monitoring Fluids in and Produced from a Subterranean Formation
[0119]
In some embodiments, the present methods can further comprise
introducing the treatment fluid into a subterranean formation. In some
embodiments, the
introduction into the subterranean formation can take place after determining
that the
treatment fluid is suitable for being introduced into the subterranean
formation. In some
embodiments, the treatment fluid can be modified while it is being introduced
into the
subterranean formation by adding at least one additional component thereto or
adjusting the
concentration of an existing component. In some embodiments, the treatment
fluid can be
modified while it is in a subterranean formation. According to the present
embodiments,
monitoring of a treatment fluid in the subterranean formation or in a flow
back fluid produced
therefrom occurs in-process. Further, according to some of the present
embodiments, a
formation fluid can be monitored using an opticoanalytical device in the
formation or in
optical communication with a fluid being produced from the formation.
[0120]
Additional information regarding the effectiveness of a treatment
operation can be obtained by continued monitoring of the treatment fluid or a
formation fluid
while it is downhole or after the treatment fluid or formation fluid is
produced from the
subterranean formation. Monitoring of formation fluids (e.g. oil) while within
the
subterranean formation or after their production from the subterranean
formation can also
provide information on the effectiveness of a treatment operation and/or
provide guidance on
how a treatment operation can be modified in order to increase production. In
some
embodiments, the present methods can further comprise monitoring a
characteristic of the
treatment fluid and/or a formation fluid using an opticoanalytical device
positioned in the
formation. In other embodiments, the present methods can further comprise
monitoring a
characteristic of a fluid produced from a subterranean formation. The produced
fluid can be a
produced formation fluid in some embodiments or a treatment fluid produced as
a flow back
fluid in other embodiments. In some embodiments, the flow back fluid and/or
the produced
38
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
formation fluid can be monitored using an opticoanalytical device that is in
optical
communication with a flow pathway for transporting the flow back fluid. In
some
embodiments, the flow back fluid can comprise an at least partially spent
treatment fluid from
the performance of a subterranean treatment operation.
[0121] In some
embodiments, the present methods can further comprise
performing a treatment operation in the subterranean formation, and monitoring
a
characteristic of the treatment fluid and/or the formation fluid after the
treatment fluid is
introduced into the subterranean formation using an opticoanalytical device.
In some
embodiments, the treatment fluid and/or formation fluid can be monitored using
an
opticoanalytical device that is located in the subterranean formation. In some
embodiments,
the treatment fluid and/or formation fluid can be monitored using an
opticoanalytical device
that is in optical communication with a flow pathway for transporting a flow
back fluid or
formation fluid produced from the subterranean formation. In some embodiments,
monitoring in the subterranean formation or of the flow back fluid and/or
produced formation
fluid can be conducted in-process during the performance of a treatment
operation.
[0122]
In some embodiments, the present methods can further comprise
adjusting a characteristic of the treatment fluid being introduced into the
subterranean
formation in response to the characteristic of the treatment fluid or
formation fluid being
monitored using the opticoanalytical device in the formation or in optical
communication
with the flow back fluid pathway. For example, if the opticoanalytical device
in the
formation or monitoring the flow back fluid indicates that a component of the
treatment fluid
is spent, or that the treatment fluid no longer has a desired characteristic
for adequately
performing a treatment operation, the treatment fluid being introduced into
the subterranean
formation can be adjusted so as to modify at least one characteristic thereof,
as described
previously. Similarly, monitoring of the formation fluid can be used in models
that evaluate
the effectiveness of a treatment operation, for example. In some embodiments,
adjustment of
the characteristic of the treatment fluid in response to a characteristic
measured in the
formation or in the flow back fluid can take place automatically under
computer control.
[0123]
In some embodiments, methods described herein can comprise:
providing a treatment fluid comprising a base fluid and at least one
additional component;
introducing the treatment fluid into a subterranean formation; allowing the
treatment fluid to
perform a treatment operation in the subterranean formation; and monitoring a
characteristic
of the treatment fluid or a formation fluid using at least a first
opticoanalytical device. In
39
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
some embodiments, the characteristic of the treatment fluid or the formation
fluid can be
monitored within the formation using the first opticoanalytical device.
In some
embodiments, the characteristic of the treatment fluid can be monitored in a
flow back fluid
produced from the formation, where the flow back fluid contains treatment
fluid from the
treatment operation. In some embodiments, the formation fluid can be monitored
during
production. In some embodiments, the characteristic of the treatment fluid
and/or the
formation fluid can both be monitored.
[0124]
When monitoring a characteristic of the treatment fluid after
introduction into a subterranean formation, monitoring the characteristic can
comprise, in
some embodiments, monitoring at least the identity and concentration of at
least one
component in the treatment fluid, the flow back fluid, or both. According to
such
embodiments, if one knows the concentration of the component prior to
introduction into the
subterranean formation, the change in concentration of the component while in
the
subterranean formation or after production from the subterranean formation
(optionally in
combination with information on the formation fluid) can provide information
about the
effectiveness of the treatment operation being conducted. For example, if the
concentration
of the component fails to change after being introduced into the subterranean
formation, it
can likely be inferred that the treatment operation had minimal to no effect
on the
subterranean formation. Likewise, if the concentration of the component
decreases after
being introduced into the subterranean formation, it is probable that the
formation has been
modified in some way by the treatment fluid. By monitoring the concentration
of a
component in a treatment fluid and/or formation fluid before and after
introduction of the
treatment fluid into a subterranean formation, a correlation between the
effectiveness of a
treatment operation can be established, in some embodiments. For example, the
change in
concentration of a component can be correlated to the effectiveness of a
treatment operation
being performed in the subterranean formation. Furthermore, if the treatment
fluid becomes
completely spent upon being introduced into the subterranean formation (that
is, the
concentration of at least one component therein drops below an effective level
or even
becomes zero), this can alert an operator or an automated system overseeing
the treatment
operation that the treatment fluid potentially needs to be altered or that the
treatment
operation potentially needs to be repeated, for example.
[0125]
In order to determine a change in concentration of at least one
component in a treatment fluid, the present methods can further comprise
monitoring a
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
characteristic of the treatment fluid before the treatment fluid is introduced
into the
subterranean formation. According to such embodiments, the pre-introduction
characteristic
can serve as a baseline value for establishing whether a change in the
characteristic has
occurred upon being introduced into the subterranean formation. In some
embodiments, the
characteristic of the treatment fluid before its introduction into the
subterranean formation
can be used as a basis for adjusting the characteristic of the treatment fluid
being introduced
into the subterranean formation.
[0126]
In some embodiments, the present methods can further comprise
determining if the characteristic of the treatment fluid being introduced into
the subterranean
formation needs to be adjusted in response to the characteristic of the
treatment fluid or the
formation fluid being monitored in the subterranean formation or in the flow
back fluid using
the opticoanalytical device. In some embodiments, the present methods can
further include
adjusting the characteristic of the treatment fluid being introduced into the
subterranean
formation in response to the characteristic of the treatment fluid or the
formation fluid
monitored in the subterranean formation or in the flow back fluid. In some
embodiments,
adjusting the characteristic of the treatment fluid can take place
automatically under computer
control. In some embodiments, an artificial neural network can be used in the
adjustment of
the treatment fluid.
[0127]
In some embodiments, tracers and/or probes can be deployed in the
treatment fluids used in the present methods. As used herein, the term
"tracer" refers to a
substance that is used in a treatment fluid to assist in the monitoring of the
treatment fluid in a
subterranean formation or in a flow back fluid being produced from a
subterranean formation.
Illustrative tracers can include, for example, fluorescent dyes,
radionuclides, and like
substances that can be detected in exceedingly small quantities. A tracer
typically does not
convey information regarding the environment to which it has been exposed,
unlike a probe.
As used herein, the term "probe" refers to a substance that is used in a
treatment fluid to
interrogate and deliver information regarding the environment to which it has
been exposed.
Upon monitoring the probe, physical and chemical information regarding a
subterranean
formation can be obtained.
[0128] In some
embodiments, the present methods can further comprise
monitoring a tracer or a probe in a treatment fluid using an opticoanalytical
device. In some
embodiments, the tracer or probe can be monitored in the flow back fluid
produced from the
subterranean formation. In other embodiments, the tracer or probe can be
monitored within
41
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
the subterranean formation. In the case of probes being monitored within a
subterranean
formation, the present methods can be particularly advantageous, since a probe
that is
produced in the flow back fluid can sometimes be altered such that it no
longer conveys an
accurate representation of the subterranean environment to which it has been
exposed. In
some embodiments, tracers or probes in the treatment fluid can be monitored
using the
opticoanalytical devices in order to determine a flow pathway for the
treatment fluid in the
subterranean formation. In some embodiments, monitoring of tracers or probes
can be used
to determine the influence of diverting agents on the flow pathway.
Conventional methods
for monitoring downhole fluid flow pathways can include, for example,
distributed
temperature sensing, as described in commonly owned United States Patent
Application
Publication 2011/0048708, which is incorporated herein by reference in its
entirety.
[0129]
In some embodiments, the treatment fluid being monitored by the
present methods can be an aqueous treatment fluid. That is, the treatment
fluids can comprise
an aqueous base fluid. Suitable aqueous base fluids can include those set
forth above. In
some embodiments, a suitable aqueous base fluid can be produced water from a
subterranean
formation. The produced water can be formation water, in some embodiments, or
the
recovered aqueous base fluid from another aqueous treatment fluid in other
embodiments.
The aqueous base fluid can be monitored using an opticoanalytical device
according to some
of the present embodiments, as described elsewhere herein.
Monitoring of Produced Water and Reuse Thereof
[0130]
Water treatment, conservation and management are becoming
increasingly important in the oilfield industry. Oftentimes, significant water
production can
accompany hydrocarbon production in a well, whether from formation water or
water used in
a stimulation operation for the well. Increasingly strict environmental
regulations have made
disposal of this water a significant issue. Due to the volumes of water
involved (millions of
gallons per well), storage of this water while awaiting conventional analyses
can be highly
problematic. Water analyses conducted according to the embodiments described
herein can
address some of these limitations in the art and provide related advantages as
well.
[0131]
In some embodiments, the methods of the present invention can be
applied toward monitoring a water obtained from a water source. In particular,
in some
embodiments, the water can comprise the base fluid being used to form a
treatment fluid. In
some embodiments, the water can be monitored to determine its suitability for
disposal or for
determining its characteristics in order to ascertain a remediation protocol
to make it suitable
42
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
for disposal. In some embodiments, methods of the present invention can
comprise
determining the suitability of a water for use as the base fluid of a
treatment fluid and, if the
water is not suitable for a particular treatment fluid, adjusting at least one
characteristic of the
water to make it suitable.
[0132] In some
embodiments, the water being monitored by the methods of
the present invention can be a produced water from a subterranean formation.
The produced
water can be formation water in some embodiments and/or comprise water from a
base fluid
that was part of a treatment fluid that performed a treatment operation in the
subterranean
formation (i.e., an aqueous flow back fluid) in other embodiments. As used
herein, the term
"produced water" refers to water obtained from a subterranean formation,
regardless of its
source. By determining the characteristics of the produced water, the
suitability of the water
for disposal or recycling as a base fluid in a subsequent treatment operation
can be
determined.
[0133]
In some embodiments, methods described herein can comprise:
providing water from a water source; monitoring a characteristic of the water
using an
opticoanalytical device; and introducing the water into a subterranean
formation. In some
embodiments, the opticoanalytical device can be in optical communication with
a flow
pathway for transporting the water.
[0134]
In some embodiments, the water can be fresh water, acidified water,
salt water, seawater, brine, aqueous salt solutions, saturated salt solutions,
municipal water,
municipal waste water, or produced water. The water source can be a surface
water source
such as, for example, a stream, a pond, an ocean, a detention pond, or a
detention tank. In
other embodiments, the water source can be a subterranean formation that
provides the
produced water. In some embodiments, a produced water can be formation water.
In other
embodiments, a produced water can be an aqueous flow back fluid obtained
following a
treatment operation. In some embodiments, the produced water can be a
combination of
formation water and an aqueous flow back fluid.
[0135]
In some embodiments, the present methods can further comprise
determining if the water is suitable for being introduced into the
subterranean formation, and
optionally, if the water is unsuitable, adjusting the characteristic of the
water. As noted
previously, determining the suitability of a fluid for introduction into a
subterranean
formation can be vital to the "health" of the subterranean formation, as the
introduction of
unwanted components can actually damage the subterranean formation or lead to
an
43
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
ineffective treatment operation. For example, the introduction of the wrong
treatment fluid to
a subterranean formation can lead to unwanted precipitation therein.
Similarly, introduction
of a treatment fluid containing bacteria can lead to biofouling or related
damage that can
impact production from a subterranean formation.
[0136] In some
embodiments, the water can be introduced directly into the
subterranean formation. For example, the water can be introduced into the
subterranean
formation as part of a water flooding operation. In some embodiments, the
water can
comprise a tracer or probe when being introduced into the subterranean
formation. In some
embodiments, the present methods can further comprise monitoring the tracer or
probe in the
subterranean formation using an opticoanalytical device or in a flow back
fluid produced
from the subterranean formation.
[0137]
In some embodiments, the water introduced into the subterranean
formation can be used for environmental monitoring. That is, the water
introduced into a
subterranean formation can be monitored at well sites remote from the
injection point to
ascertain the movement of a fluid through and out of a subterranean formation.
In some
embodiments, an opticoanalytical device of the present invention can be used
for monitoring
the water at the remote well sites. In some embodiments, tracers or probes can
be used in the
water when environmental monitoring applications are conducted.
[0138]
In other embodiments, the water can be introduced into the
subterranean formation in a treatment fluid. That is, in some embodiments, the
treatment
fluid can comprise the water. In some embodiments, a property of the water can
be adjusted
by adding at least one additional component to the water. In some embodiments,
the
combination of the water and the at least one other component can be
considered to constitute
the treatment fluid. In other embodiments, a property of the water can be
adjusted by adding
at least one other component to the water prior to forming the treatment
fluid, and still
another additional component can be added thereafter to form the treatment
fluid. That is, a
treatment fluid formed in such a manner comprises at least two additional
components. A
reason one might form a treatment fluid in this manner is if a characteristic
of the unmodified
water would be detrimental to a component being used to form the treatment
fluid. In this
case, a first component could be added to adjust the characteristic of the
water so as to no
longer be detrimental to the second component being added subsequently. In
alternative
embodiments, a property of the water can be adjusted by removing at least one
component
44
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
from the water prior to forming a treatment fluid or by performing at least
one water
treatment on the water.
[0139]
In some embodiments, methods of the present invention can further
comprise combining at least one additional component with the water so as to
alter at least
one property thereof. In some embodiments, the methods can further comprise
monitoring a
characteristic of the water using an opticoanalytical device after adding the
at least one
additional component. In some embodiments, monitoring the characteristic of
the water after
adding the at least one additional component can take place using an
opticoanalytical device
that is in optical communication with a flow pathway for transporting the
water. In such
embodiments, the opticoanalytical device can be used to ascertain if the at
least one
additional component has altered the characteristic of the water in desired
fashion. For
example, after adding the at least one additional component, the
opticoanalytical device can
be used to determine if a component added to the water (which can be a
component already
in the water) lies within a desired concentration range. In alternative
embodiments,
monitoring of the water using the opticoanalytical device can take place
offline. In some
embodiments, combining the at least one additional component with the water
can take place
automatically under computer control in response to a characteristic of the
water monitored
using an opticoanalytical device. In some embodiments, remote monitoring and
adjustment
can be conducted.
[0140] In some
embodiments, methods of the present invention can comprise:
producing water from a first subterranean formation, thereby forming a
produced water;
monitoring a characteristic of the produced water using an opticoanalytical
device; forming a
treatment fluid comprising the produced water and at least one additional
component; and
introducing the treatment fluid into the first subterranean formation or a
second subterranean
formation. In some embodiments, the opticoanalytical device can be in
optical
communication with a flow pathway for transporting the produced water. In
other
embodiments, monitoring the characteristic of the water using the
opticoanalytical device can
take place off-line.
[0141]
In some embodiments, the methods can further comprise monitoring a
characteristic of the treatment fluid using another opticoanalytical device.
In some
embodiments, the opticoanalytical device used for monitoring the treatment
fluid can be in
optical communication with a flow pathway for transporting the treatment
fluid. In other
embodiments, monitoring of the treatment fluid using the opticoanalytical
device can take
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
place off-line. In some embodiments, the treatment fluid can be monitored
using the
opticoanalytical device before it has been introduced into the subterranean
formation. In
other embodiments, the treatment fluid can be monitored after it has been
introduced into the
subterranean formation, either in the formation itself or in a flow back fluid
produced from
the subterranean formation. In some embodiments, the formation fluid can also
be
monitored.
[0142]
In some embodiments, methods of the present invention can comprise:
providing water from a water source; monitoring a characteristic of the water
using an
opticoanalytical device; and treating the water so as to alter at least one
property thereof. In
some embodiments, treating the water can be conducted in response to the
characteristic of
the water monitored using the opticoanalytical device. In some embodiments,
the
opticoanalytical device can be in optical communication with a flow pathway
for transporting
the water.
[0143]
In some embodiments, treating the water can comprise adding at least
one component to the water. In some embodiments, treating the water can
comprise
increasing the concentration of an existing component in the water. In other
embodiments,
treating the water can comprise removing at least one component from the
water. For
example, the water can be subjected to a water purification technique.
Illustrative water
purification techniques are well known in the art and can include, for
example, filtration,
treatment with activated carbon, ion-exchange, reverse osmosis and the like.
Generally, these
water purification techniques remove at least one component from the water or
modify at
least one component in the water in order to modify the water's properties. In
some
embodiments, the water can be monitored with an opticoanalytical device after
the water
treatment takes place in order to determine if the water has the
characteristics desired. In
some embodiments, treating the water can comprise a bactericidal treatment
such as, for
example, exposure to ultraviolet light, electrocoagulation, or ozonolysis.
[0144]
In some embodiments, the water can be selectively treated to remove,
inactivate, or destroy components that can interfere with the formation of a
treatment fluid or
the effectiveness of a treatment fluid in a subterranean formation. For
example, a water
treatment process can be designed to render the water suitable for use in a
treatment fluid
without complete purification being achieved. Suitable water treatment
processes for oilfield
treatment fluids are described in commonly owned United States Patent
Applications
46
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
12/722,410; 13/007,363; and 13/007,369, each of which is incorporated herein
by reference
in its entirety.
[0145]
In some embodiments, the present methods can further comprise
disposing of the water after treating the water. In such embodiments, the
water treatment can
be chosen so as to make the water suitable for disposal. In some embodiments,
the water can
be monitored using an opticoanalytical device after being treated so as to
verify that the water
has been modified in a desired way, thereby making it suitable for disposal.
In alternative
embodiments, the water can be disposed of without additional treatment taking
place if it is
determined, using an opticoanalytical device, that the water is already
suitable for disposal.
[0146] In some
embodiments, water being produced from a subterranean
formation can be recycled for use as the base fluid of a treatment fluid being
introduced into
the same subterranean formation or a different subterranean formation. Various
types of
treatment fluids that can be produced and monitored according to the methods
described
herein have been set forth previously. Depending on the intended treatment
operation, the
characteristic(s) of the water being monitored will likely vary from
application to application.
For example, when performing a fracturing operation, the certain ionic
species, if present, can
impact the outcome of a fracturing operation. Likewise, in an acidizing
operation,
particularly of a silica-containing subterranean formation, the presence of
calcium ions in the
base fluid can cause unwanted precipitation during the acidizing operation. In
some cases,
the water can contain materials that, if present, can lead to ineffective
crosslinking of
crosslinking agents and therefore impact the treatment fluid's rheological
profile.
[0147]
In some embodiments, treatment fluids comprising water, particularly
water produced from a subterranean formation, can be used as fracturing
fluids. In such
embodiments, the treatment fluid can be introduced into a subterranean
formation at a
pressure sufficient to create or enhance at least one fracture therein. In
some embodiments,
monitoring a characteristic of a water to be used in a treatment operation can
comprise
monitoring the water for an ionic material. In this regard, the present
methods can be
particularly advantageous, since certain ionic materials, if present, can
detrimentally impact a
fracturing operation. These ionic materials can include, for example, iron-
containing ions
(e.g., Fe2+, Fe3+ and iron containing complex ions), iodine-containing ions
(e.g., E and 13),
boron-containing ions (e.g., B03), sulfur-containing ions (e.g., S042-, S032-
and S2), barium
ions, strontium ions, magnesium ions, or any combination thereof Other
components of the
water can also be detrimental to fracturing operations and will be recognized
by one having
47
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
ordinary skill in the art. For example, other ionic materials that can be of
interest to monitor
in a water can include, for example, carbonate ions, sodium ions, potassium
ions, aluminum
ions, calcium ions, manganese ions, lithium ions, cesium ions, chromium ions,
fluoride ions,
chloride ions, bromide ions, iodide ions, arsenic ions, lead ions, mercury
ions, nickel ions,
copper ions, zinc ions, titanium ions and the like. In addition, the presence
of certain
dissolved minerals in the water can also be of interest. Neutral molecules
such as, for
example, molecular iodine and boric acid can also be problematic as well.
Still further,
dissolved organic compounds in the water can also be monitored by using
opticoanalytical
devices according to the present methods.
[0148] Without
being bound by any theory or mechanism in the following
discussion, it is believed that certain ionic materials can be detrimental to
fracturing
operations for a number of different reasons. For example, sodium and
potassium ions can
affect hydration of polymers. Other ions such as, for example, borate, iron,
sodium and
aluminum ions can compete for crosslinking sites. In addition, some
characteristics of a
water can affect the ability to control the pH of a fluid produced therefrom.
All of these
factors can influence the overall rheological properties and ultimate
performance of a
fracturing fluid.
[0149]
In some embodiments, detection of the ionic materials can take place
directly using the opticoanalytical device. In some embodiments, the
opticoanalytical device
can be specifically configured to detect the ionic materials of interest. In
other embodiments,
dyes or other molecular tags can be used that react with the ionic materials
in order to
produce a detectable species. That is, the opticoanalytical device can be
specifically
configured to detect the reaction product of the dye or tag with the ionic
species. Dyes and
tags can be used, for example, when the ionic species is not readily
detectable alone or if the
sensitivity is not as great as desired. Other types of components in the water
can be detected
using dyes and tags as well.
[0150]
It should be noted that the monitoring of water obtained from a water
source is not limited to ionic materials. For example, in some embodiments,
neutral
substances (e.g., boric acid, molecular iodine, and organic compounds) can be
monitored. In
other embodiments, biologics such as bacteria and the like can be monitored
using the present
methods.
[0151]
In some embodiments, upon identification of a substance in the water
that is known to be detrimental to fracturing operations or another type of
treatment
48
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
operation, a characteristic of the water can be adjusted by adding at least
one additional
component thereto. In some embodiments, the addition of the at least one
additional
component to the water can create a treatment fluid having a custom
formulation that is not
typically used when a water source having a relatively consistent composition
is used for
forming a treatment fluid. Specifically, a water from a surface water source
can many times
have a composition that is relatively consistent from batch to batch, unless a
contamination
event has occurred, allowing treatment fluids having known, relatively
constant compositions
to be formulated. In contrast, a produced water can have a widely varying
composition from
batch to batch, depending on the type of subterranean formation from which it
was obtained
and any treatment operation that was previously performed in the subterranean
formation. In
order to address the variable characteristics of produced water, an array of
additional
components can be added thereto, some of which may not be commonly used in
treatment
fluids. In this regard, methods of the present invention can be particularly
advantageous, as
they can be capable of addressing the widely varying compositions encountered
in produced
waters by making predictive estimations of properties and conducting automatic
adjustment
and monitoring of those properties under computer control during the addition
of at least one
component to the produced water.
Applications to Fracturing Fluids and Fracturing Operations
[0152]
In some embodiments, methods of the present invention can be used to
monitor the formation of fracturing fluids and the performance of fracturing
fluids during
fracturing operations conducted in a subterranean formation. In addition to
the issues with
fracturing fluids noted above, other fracturing components in the fracturing
fluid can be
monitored using the present methods to determine the suitability of a
fracturing fluid for
performing a fracturing operation and to evaluate the effectiveness of a
fracturing operation.
Particularly, the present methods can be used to monitor a characteristic of a
fracturing fluid
during its formation and subsequent introduction into a subterranean formation
at a pressure
sufficient to create or enhance at least one fracture therein.
[0153]
As non-limiting examples of how the present methods can be
advantageous for monitoring a fracturing fluid, the present methods can be
used to monitor a
fracturing fluid's viscosity or the type of proppant particulates therein. A
fracturing fluid
having an insufficient viscosity may not have the capacity for supporting a
proppant in the
fracturing fluid, thereby leading to the failure of a fracturing operation.
Likewise, the wrong
type, size or concentration of proppant particulates can lead to the failure
of a fracturing
49
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
operation. Similar characteristics can be monitored during a fracturing
operation in order to
evaluate its effectiveness.
[0154]
According to the present embodiments, the fracturing fluid can
comprise any number of fracturing fluid components. In at least some
embodiments, the
fracturing fluid can contain at least a base fluid and proppant particulates,
in addition to other
fracturing fluid components. Other fracturing fluid components that can be
present in the
fracturing fluid include, for example, a surfactant, a gelling agent, a
crosslinking agent, a
crosslinked gelling agent, a diverting agent, a salt, a scale inhibitor, a
corrosion inhibitor, a
chelating agent, a polymer, an anti-sludging agent, a foaming agent, a buffer,
a clay control
agent, a consolidating agent, a breaker, a fluid loss control additive, a
relative permeability
modifier, a tracer, a probe, nanoparticles, a weighting agent, a rheology
control agent, a
viscosity modifier (e.g., fibers and the like), and any combination thereof
Any of these
fracturing fluid components can influence the characteristics of the
fracturing fluid and can
be monitored according to the methods described herein using opticoanalytical
devices.
[0155] In some
embodiments, methods for forming a fracturing fluid can
comprise: providing at least one fracturing fluid component; combining the at
least one
fracturing fluid component with a base fluid to form a fracturing fluid; and
monitoring a
characteristic of the fracturing fluid using an opticoanalytical device. In
some embodiments,
the opticoanalytical device can be in optical communication with a flow
pathway for
transporting the fracturing fluid.
[0156]
In some embodiments, monitoring a characteristic of the fracturing
fluid can comprise monitoring at least the identify and concentration of the
at least one
fracturing fluid component in the fracturing fluid by using the
opticoanalytical device. For
example, in some embodiments, the identity and concentration of proppant
particulates or a
surfactant can be monitored in the fracturing fluid. In some embodiments,
monitoring a
characteristic of the fracturing fluid can comprise monitoring the fracturing
fluid for
impurities using the opticoanalytical device. In some embodiments, the
impurities can be
known impurities, where the opticoanalytical device has been configured to
detect those
impurities. In other embodiments, the impurities can be unknown impurities,
where the
presence of the impurities can be inferred by the characteristics of the
fracturing fluid
determined by the opticoanalytical device.
[0157]
In some embodiments, the present methods can further comprise
transporting the fracturing fluid to a pump, and introducing the fracturing
fluid into a
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
subterranean formation at a pressure sufficient to create or enhance at least
one fracture
therein. In some embodiments, a characteristic of the fracturing fluid can be
monitored while
being transported to the pump by using an opticoanalytical device located at
the pump.
[0158]
In some embodiments, the present methods can further comprise
determining if the characteristic of the fracturing fluid being monitored
makes the fracturing
fluid suitable for being introduced into the subterranean formation, and
optionally, if the
fracturing fluid is unsuitable, adjusting the characteristic of the fracturing
fluid. In some
embodiments, determining if the fracturing fluid is suitable and adjusting the
characteristic of
the fracturing fluid can take place automatically under computer control. In
some
embodiments, adjusting the characteristic of the fracturing fluid can take
place manually. In
some embodiments, adjusting the characteristic of the fracturing fluid can
comprise adjusting
the concentration of at least one fracturing fluid component in the fracturing
fluid or adding
at least one additional fracturing fluid component to the fracturing fluid.
[0159]
In some embodiments, monitoring the characteristic of the fracturing
fluid and adjusting the characteristic of the fracturing fluid can take place
by remote
monitoring. Automated control and remote operation can be particularly
advantageous for
fracturing operations. Information from the opticoanalytical devices can be
integrated with
fracturing equipment information in real-time or near real-time to monitor and
control
fracturing operations. In addition, the fracturing information, including
information from
opticoanalytical devices, can be sent by satellite, wide area network systems
or other
communication systems to a remote location to further enhance job execution.
Monitoring
and control of the fracturing operation can then take place from this remote
location. In some
embodiments, remote operation can take place automatically under computer
control.
[0160]
In some embodiments, the present methods can further comprise
introducing the fracturing fluid into a subterranean formation at a pressure
sufficient to create
or enhance at least one fracture therein. In some embodiments, the methods can
further
comprise monitoring a characteristic of the fracturing fluid or a formation
fluid using an
opticoanalytical device within the subterranean formation. In some
embodiments, the present
methods can further comprise producing a flow back fluid from the subterranean
formation
and monitoring a characteristic of the flow back fluid or a produced formation
fluid using an
opticoanalytical device. In some embodiments, the opticoanalytical device
monitoring the
flow back fluid or produced formation fluid can be in optical connection with
a flow pathway
for transporting the flow back fluid.
51
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
[0161]
In some embodiments, methods described herein can comprise:
providing a fracturing fluid comprising at least one fracturing fluid
component; introducing
the fracturing fluid into a subterranean formation at a pressure sufficient to
create or enhance
at least one fracture therein; and monitoring a characteristic of the
fracturing fluid using an
opticoanalytical device. In some embodiments, the opticoanalytical device can
be in optical
communication with a flow pathway for transporting the fracturing fluid before
introducing
the fracturing fluid into the subterranean formation.
[0162]
In some embodiments, the methods can further comprise performing a
fracturing operation in the subterranean formation and monitoring a
characteristic of the
fracturing fluid or a formation fluid after the fracturing fluid is introduced
into the
subterranean formation using another opticoanalytical device. In such
embodiments, the
opticoanalytical device can be located in the subterranean formation or in
optical
communication with a flow pathway for transporting a flow back fluid produced
from the
subterranean formation. In some embodiments, the characteristic of the
fracturing fluid being
introduced into the subterranean formation can be adjusted in response to the
characteristic of
the fracturing fluid or the formation fluid being monitored using the
opticoanalytical device
in the subterranean formation or monitoring the flow back fluid or produced
formation fluid.
[0163]
In some embodiments, methods for monitoring a fracturing fluid can
comprise: forming a fracturing fluid on-the-fly by adding at least one
fracturing fluid
component to a base fluid stream; introducing the fracturing fluid into a
subterranean
formation at a pressure sufficient to create or enhance at least one fracture
therein; and
monitoring a characteristic of the fracturing fluid while it is being
introduced into the
subterranean formation using an opticoanalytical device. In some embodiments,
the methods
can further comprise determining if the characteristic of the fracturing fluid
being monitored
using the opticoanalytical device makes the fracturing fluid suitable for
being introduced into
the subterranean formation, and, optionally, if the fracturing fluid is
unsuitable, adjusting the
characteristic of the fracturing fluid.
[0164]
In some embodiments, methods described herein can comprise:
providing a fracturing fluid comprising a base fluid and at least one
fracturing fluid
component; introducing the fracturing fluid into a subterranean formation at a
pressure
sufficient to create or enhance at least one fracture therein, thereby
performing a fracturing
operation in the subterranean formation; and monitoring a characteristic of
the fracturing
fluid or a formation fluid using an opticoanalytical device. In some
embodiments, the
52
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
characteristic of the fracturing fluid or the formation fluid can be monitored
in-process within
the subterranean formation, in a flow back fluid or formation fluid produced
from the
subterranean formation, or both, while the fracturing operation is being
conducted.
[0165]
In some embodiments, the methods can further comprise determining
if the characteristic of the fracturing fluid being introduced into the
subterranean formation
needs to be adjusted in response to a concentration of at least one fracturing
component being
monitored with an opticoanalytical device in the subterranean formation, or in
optical
communication with a flow pathway of a flow back fluid being produced from the
subterranean formation. In some embodiments, the methods can further comprise
adjusting
the characteristic of the fracturing fluid being introduced into the
subterranean formation. In
some embodiments, determining if the characteristic of the fracturing fluid
needs to be
adjusted and adjusting the characteristic of the fracturing fluid can take
place automatically
under computer control.
[0166]
In some embodiments, methods for performing a fracturing operation
can further comprise monitoring a characteristic of the fracturing fluid using
an
opticoanalytical device that is in optical communication with a flow pathway
for transporting
the fracturing fluid, where monitoring takes place before the fracturing fluid
is introduced
into the subterranean formation. In some embodiments, the methods can comprise
determining a change in concentration of at least one fracturing fluid
component, based upon
monitoring of the component before and after the fracturing fluid is
introduced into the
subterranean formation. In some embodiments, the change in concentration of
the at least
one fracturing fluid component can be correlated to an effectiveness of the
fracturing
operation being conducted in the subterranean formation. In some embodiments,
the
concentration of a component in a formation fluid can likewise be correlated
to an
effectiveness of the fracturing operation as well.
[0167]
Analyses of produced fluids resulting from a fracturing operation (i.e.,
flow back fluids and formation fluids) can be used in models to estimate
reservoir and
fracture properties. The methods described herein can be used to supplement
and beneficially
increase the speed of these analyses. In particular, the composition of
flowback water and
formation water can be modeled to obtain information on permeability,
conductivity, fracture
dimensional features, and related information (See Gdanski et at, "A New Model
for
Matching Fracturing Fluid Flowback Composition," SPE 106040 presented at the
2007 SPE
Hydraulic Fracturing Technology Conference held in College Station, Texas,
U.S.A., January
53
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
29 ¨ 31, 2007 and Gdanski et at, "Using Lines-of-Solutions to Understand
Fracture
Conductivity and Fracture Cleanup," SPE 142096 presented at the SPE Production
and
Operations Symposium held in Oklahoma City, Oklahoma, U.S.A., March 27 ¨ 29,
2011).
Methods for estimating properties of a subterranean formation and determining
fracture
characteristics in a subterranean formation from flowback fluid data are also
described in
commonly owned United States Patent 7,472,748, which is incorporated herein by
reference
in its entirety.
[0168]
In some embodiments, a tracer or probe in the fracturing fluid can be
monitored using an opticoanalytical device. Monitoring the tracer or probe can
also be
beneficial for determining the effectiveness of a fracturing operation. For
example, by
monitoring a tracer or probe in the fracturing fluid using an opticoanalytical
device, a flow
pathway within the subterranean formation can be determined, in some
embodiments.
[0169]
In some embodiments, the present methods can be used to monitor a
flow pathway of a fracturing fluid to which has been added a diverting agent.
For example,
one or more opticoanalytical devices in a subterranean formation can be used
to determine
where a fracturing fluid or other treatment fluid is flowing before the
diverting agent is added
to the treatment fluid. After the diverting agent is added, the
opticoanalytical devices can be
used to determine if the flow pathway has changed within the subterranean
formation.
[0170]
In some embodiments, methods described herein can comprise:
providing a fracturing fluid comprising a base fluid and at least one
fracturing fluid
component; introducing the fracturing fluid into a subterranean formation at a
pressure
sufficient to create or enhance at least one fracture therein; and monitoring
a characteristic of
the fracturing fluid using an opticoanalytical device before the fracturing
fluid is introduced
into the subterranean formation. In some embodiments, the opticoanalytical
device can be in
optical communication with a flow pathway for transporting the fracturing
fluid. In some
embodiments, the methods can further comprise monitoring a characteristic of
the fracturing
fluid or a formation fluid after the fracturing fluid is introduced into the
subterranean
formation, where the fracturing fluid can be monitored in-process within the
subterranean
formation or in a flow back fluid produced from the subterranean formation.
[0171] In some
embodiments, the present methods can further comprise
monitoring at least the identity and concentration of at least one fracturing
fluid component
using an opticoanalytical device, before the fracturing fluid component is
used to form a
treatment fluid. In some embodiments, monitoring the at least one fracturing
fluid
54
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
component can be conducted with an opticoanalytical device that is in optical
communication
with a flow pathway for transporting the fracturing fluid component. In other
embodiments,
the opticoanalytical device can be located in a storage vessel for the
fracturing fluid
component.
Applications to Acidizing Fluids and Acidizing Operations
[0172]
In some embodiments, methods of the present invention can be used to
monitor the formation of acidizing fluids and the performance of acidizing
operations in a
subterranean formation. In various embodiments, the acidizing fluids can
contain at least one
acid. Most typically, the at least one acid can be selected from hydrochloric
acid,
hydrofluoric acid, formic acid, acetic acid, glycolic acid, lactic acid, and
the like.
Hydrochloric acid is typically used for acidizing limestone and carbonate-
containing
subterranean formations. Hydrofluoric acid is typically used for acidizing
silicate-containing
formations, including sandstone. It should be recognized by one having
ordinary skill in the
art that other acids or mixtures of acids can be used as well. The choice of
an acid blend
suitable for a particular subterranean formation will most often be a matter
of routine design
for one having ordinary skill in the art. In addition, suitable compounds that
form acids
downhole (i.e., acid precursors) can also be used. For example, esters,
orthoesters and
degradable polymers such as polylactic acid can be used to generate an acid in
the
subterranean formation. As one of ordinary skill in the art will also
appreciate, the
introduction of an acidizing fluid not having the proper characteristics or
composition during
an acidizing operation can have significant consequences on the success
thereof, as damage
to the subterranean formation can occur if the wrong acid is used. For
example, precipitation
of formation solids can occur in certain instances.
[0173]
In addition to at least one acid, acidizing fluids suitable for use in the
present embodiments can also contain other components in addition to the at
least one acid.
Two of the more notable components are chelating agents and/or corrosion
inhibitors, for
example. Chelating agents can slow or prevent the precipitation of formation
solids, even
when the proper acid is used during the treatment operation. Corrosion
inhibitors can slow or
prevent the degradation of metal tools used during the performance of an
acidizing operation.
If either of these components are out of range in an acidizing fluid being
introduced into a
subterranean formation, serious consequences in the performance of an
acidizing operation
can result. Other components that can optionally be present in the acidizing
fluid include for
example, a surfactant, a gelling agent, a salt, a scale inhibitor, a polymer,
an anti-sludging
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
agent, a diverting agent, a foaming agent, a buffer, a clay control agent, a
consolidating agent,
a breaker, a fluid loss control additive, a relative permeability modifier, a
tracer, a probe,
nanoparticles, a weighting agent, a rheology control agent, a viscosity
modifier, and any
combination thereof Any of these additional components can also be monitored
using an
opticoanalytical device according to the methods described herein.
[0174]
In some embodiments, methods for forming an acidizing fluid can
comprise: providing at least one acid; combining the at least one acid with a
base fluid to
form an acidizing fluid; and monitoring a characteristic of the acidizing
fluid using an
opticoanalytical device. In some embodiments, the opticoanalytical device can
be in optical
communication with a flow pathway for transporting the acidizing fluid.
[0175]
In some embodiments, monitoring a characteristic of the acidizing
fluid can comprise monitoring at least the identity and concentration of the
at least one acid in
the acidizing fluid by using the opticoanalytical device. In some embodiments,
monitoring a
characteristic of the acidizing fluid can comprise monitoring at least the
identity and
concentration of at least one additional component in the acidizing fluid
using the
opticoanalytical device. Additional components can include those set forth
above. In some
embodiments, monitoring a characteristic of the acidizing fluid can comprise
monitoring the
acidizing fluid for impurities using the opticoanalytical device. In some
embodiments, the
impurities can be known impurities, where the opticoanalytical device has been
configured to
detect those impurities. In other embodiments, the impurities can be unknown
impurities,
where the presence of the impurities can be inferred by the characteristics of
the acidizing
fluid determined by the opticoanalytical device.
[0176]
In some embodiments, the present methods can further comprise
transporting the acidizing fluid to a pump, and introducing the acidizing
fluid into a
subterranean formation. In some embodiments, a characteristic of the acidizing
fluid can be
monitored using an opticoanalytical device while being transported to the
pump. In some
embodiments, the opticoanalytical device can be located at the pump.
[0177]
In some embodiments, the present methods can further comprise
determining if the characteristic of the acidizing fluid being monitored makes
the acidizing
fluid suitable for being introduced into the subterranean formation, and
optionally, if the
acidizing fluid is unsuitable, adjusting the characteristic of the acidizing
fluid. In some
embodiments, adjusting the characteristic of the acidizing fluid can take
place automatically
under computer control. In some embodiments, adjusting the characteristic of
the acidizing
56
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
fluid can take place manually. In some embodiments, adjusting the
characteristic of the
acidizing fluid can comprise adjusting the concentration of the at least one
acid therein. In
some embodiments, adjusting the characteristic of the acidizing fluid can take
place through
remote monitoring and control.
[0178] In some
embodiments, the present methods can further comprise
introducing the acidizing fluid into a subterranean formation. In some
embodiments, the
methods can further comprise monitoring a characteristic of the acidizing
fluid or a formation
fluid using an opticoanalytical device within the subterranean formation. In
some
embodiments, the present methods can further comprise producing a flow back
fluid from the
subterranean formation and monitoring a characteristic of the flow back fluid
or a produced
formation fluid using an opticoanalytical device that is in optical
communication with a flow
pathway for transporting the flow back fluid. In some embodiments, monitoring
a
characteristic of the acidizing fluid in the subterranean formation or in the
flow back fluid
produced from the subterranean formation can occur in-process while an
acidizing operation
is being performed.
[0179]
In some embodiments, the present methods can further comprise
adjusting a characteristic of the acidizing fluid being introduced into the
subterranean
formation in response to a characteristic of the acidizing fluid being
monitored using an
opticoanalytical device located at a pump for introducing the acidizing fluid
into the
subterranean formation.
[0180]
In some embodiments, methods described herein can comprise:
providing an acidizing fluid comprising at least one acid; introducing the
acidizing fluid into
a subterranean formation; and monitoring a characteristic of the acidizing
fluid using an
opticoanalytical device. In some embodiments, the opticoanalytical device can
be in optical
communication with a flow pathway for transporting the acidizing fluid.
[0181]
In some embodiments, the methods can further comprise performing
an acidizing operation in the subterranean formation, and monitoring a
characteristic of the
acidizing fluid or a formation fluid after the acidizing fluid is introduced
into the subterranean
formation using another opticoanalytical device. In such embodiments, the
opticoanalytical
device can be located in the subterranean formation or in optical
communication with a flow
pathway for transporting a flow back fluid produced from the subterranean
formation. In
some embodiments, the characteristic of the acidizing fluid being introduced
into the
subterranean formation can be adjusted in response to the characteristic of
the acidizing fluid
57
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
or formation fluid being monitored using the opticoanalytical device in the
subterranean
formation or monitoring the flow back fluid.
[0182]
In some embodiments, methods described herein can comprise:
forming an acidizing fluid on-the-fly by adding at least one acid to a base
fluid stream;
introducing the acidizing fluid into a subterranean formation; and monitoring
a characteristic
of the acidizing fluid using an opticoanalytical device while the acidizing
fluid is being
introduced into the subterranean formation. In some embodiments, the methods
can further
comprise determining if the characteristic of the acidizing fluid being
monitored using the
opticoanalytical device makes the acidizing fluid suitable for being
introduced into the
subterranean formation, and, optionally, if the acidizing fluid is unsuitable,
adjusting the
characteristic of the acidizing fluid.
[0183]
In some embodiments, methods for performing an acidizing operation
can comprise: providing an acidizing fluid comprising a base fluid and at
least one acid;
introducing the acidizing fluid into a subterranean formation; allowing the
acidizing fluid to
perform an acidizing operation in the subterranean formation; and monitoring a
characteristic
of the acidizing fluid or a formation fluid using an opticoanalytical device.
In some
embodiments, the characteristic of the acidizing fluid or the formation fluid
can be monitored
in-process within the subterranean formation, in a flow back fluid produced
from the
subterranean formation, or both.
[0184] In some
embodiments, monitoring a characteristic of the acidizing
fluid can comprise monitoring at least the identity and concentration of the
at least one acid in
the acidizing fluid, the flow back fluid, or both. In some embodiments, the
methods can
further comprise determining if the characteristic of the acidizing fluid
being introduced into
the subterranean formation needs to be adjusted in response to the
concentration of the at
least one acid being monitored using the opticoanalytical device in the
subterranean
formation or in optical communication with a flow pathway for transporting a
flow back fluid
produced therefrom. In some embodiments, the methods can further comprise
adjusting the
characteristic of the acidizing fluid being introduced into the subterranean
formation. In
some embodiments, determining if the characteristic of the acidizing fluid
needs to be
adjusted and adjusting the characteristic of the acidizing fluid can take
place automatically
under computer control.
[0185]
In some embodiments, the methods can further comprise monitoring a
characteristic of the acidizing fluid using an opticoanalytical device before
the acidizing fluid
58
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
is introduced into the subterranean formation. In some embodiments, the
opticoanalytical
device can be in optical communication with a flow pathway for transporting
the acidizing
fluid. In some embodiments, a change in concentration of at least one acid or
other
component in the acidizing fluid can be determined by monitoring the acidizing
fluid before
and after it is introduced into the subterranean formation. In some
embodiments, the change
in concentration of the at least one acid or other component in the acidizing
fluid can be
correlated to an effectiveness of an acidizing operation being conducted in
the subterranean
formation.
[0186]
In some embodiments, a tracer or probe in the acidizing fluid or the
flow back fluid can be monitored using an opticoanalytical device according to
the present
methods.
[0187]
In some embodiments, methods described herein can comprise:
providing an acidizing fluid comprising a base fluid and at least one acid;
introducing the
acidizing fluid into a subterranean formation; and monitoring a characteristic
of the acidizing
fluid using an opticoanalytical device before the acidizing fluid is
introduced into the
subterranean formation. In some embodiments, the opticoanalytical device can
be in optical
communication with a flow pathway for transporting the acidizing fluid.
[0188]
In some embodiments, the methods can further comprise determining
if the characteristic of the acidizing fluid being introduced into the
subterranean formation
needs to be adjusted in response to the characteristic of the acidizing fluid
being monitored
using the opticoanalytical device. In some embodiments, the methods can
further comprise
adjusting the characteristic of the acidizing fluid. In some embodiments,
determining if the
characteristic of the acidizing fluid needs to be adjusted and adjusting the
characteristic of the
acidizing fluid can take place automatically under computer control.
[0189] In some
embodiments, the methods can further comprise monitoring a
characteristic of the acidizing fluid or a formation fluid in-process using an
opticoanalytical
device, where the characteristic is measured in the subterranean formation, in
a flow back
fluid produced from the subterranean formation, or both.
Monitoring of Bacteria
[0190] In some
embodiments, the methods described hereinabove can be
extended to the monitoring of bacteria in a fluid, particularly a treatment
fluid in a
subterranean formation or being introduced into a subterranean formation. The
monitoring of
bacteria in or near real-time is presently believed to be unfeasible using
current spectroscopic
59
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
techniques, particularly at low bacterial levels. The present methods can
overcome this
limitation in the art.
[0191]
In particular regard to subterranean operations, water used in various
subterranean operations can be obtained from a number of "dirty" water
sources, having
varying levels of bacterial contamination therein. Although bacterial
contamination may not
be particularly problematic in treatment fluid when it is on the surface, once
the treatment
fluid is introduced into a warm subterranean environment, even low levels of
bacteria can
multiply quickly, potentially leading to damage of the subterranean formation.
In some
cases, biofouling of the surface of the subterranean formation can occur.
Specifically,
anaerobic H25-producing bacteria can be particularly detrimental to
subterranean operations.
Rapidly multiplying bacteria and their metabolic byproducts can quickly clog
and corrode
production tubulars, plug formation fractures and produce H25 which presents a
health hazard
and can lead to completion failure and loss of production. Accordingly, it is
highly desirable
to reduce bacteria levels in a treatment fluid before it is introduced into a
subterranean
formation.
[0192]
A number of techniques are known for killing bacteria to reduce
bacterial loads in a sample (e.g., exposure to ultraviolet light, ozonolysis,
electrocoagulation,
biocidal treatments and the like). However, it is believed that no current
techniques are
available for real-time or near real-time monitoring of bacterial load and for
monitoring the
effectiveness of a bactericidal treatment process to determine if bacterial
load in a sample has
been reduced to a sufficient degree. Without being bound by theory or
mechanism, it is
believed that bactericidal treatments such as, for example, ultraviolet light
exposure, rapidly
alter the deoxyribonucleic acid (DNA) and/or ribonucleic acid (RNA) of the
bacteria,
sometimes in conjunction with rupturing of their cell walls, to result in
their eventual death.
[0193] In some
embodiments, opticoanalytical devices described herein can
be used to monitor bacteria according to the present embodiments by monitoring
the DNA or
RNA of the bacteria, and the changes thereto, as a result of a bactericidal
treatment. The
opticoanalytical devices, in some embodiments, can be configured for detecting
the DNA or
RNA of live bacteria, and the increase or decrease in the amount of DNA or RNA
can be
used to effectively monitor the amount of live bacteria in the sample. In some
embodiments,
the opticoanalytical devices can be configured to detect the DNA or RNA of
specific types of
bacteria. In some embodiments, fluorescent emission from the DNA or RNA can be
used as
an extremely sensitive detection technique for the DNA or RNA. Thus, the
present methods
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
can be suitable for fluids having low bacterial loads (e.g., as low as about
1000 bacteria/mL).
As increasing numbers of bacteria have their DNA or RNA changed by the
bactericidal
treatment, the amount detected by the opticoanalytical devices will
correspondingly decrease.
The decrease in the amount of DNA or RNA can be directly correlated to the
number of
viable bacteria in the sample. Correspondingly, if it observed that the amount
of DNA or
RNA in a sample is increasing, the increase can be indicative of bacterial
growth, which can
suggest the necessity for performing a bactericidal treatment. In alternative
embodiments,
dead or dying bacteria that have altered DNA or RNA can also be monitored by
the present
methods, provided that the opticoanalytical device is configured for the
altered DNA or RNA
of these species.
[0194]
In some embodiments, methods described herein can comprise:
monitoring bacteria in water using an opticoanalytic device that is in optical
communication
with the water. In some embodiments, the water can be flowing through a flow
pathway
while monitoring the bacteria takes place. In some embodiments, the bacteria
can be live
bacteria. In other embodiments, the bacteria can be dead or dying bacteria. In
some
embodiments, monitoring can take place on a static water sample. In other
embodiments,
monitoring can take place while the water is flowing through a flow pathway.
[0195]
In some embodiments, methods for monitoring bacteria can comprise:
exposing water to a bactericidal treatment; and after exposing the water to
the bactericidal
treatment, monitoring live bacteria in the water using an opticoanalytical
device that is in
optical communication with the water.
[0196]
In some embodiments, the monitoring live bacteria in the water can
comprise monitoring DNA or RNA from the live bacteria. As noted previously,
the DNA or
RNA of the live bacteria can be distinguished from the DNA or RNA of dead,
dying or non-
viable bacteria due to a structural change affected by a bactericidal
treatment. In some
embodiments, the present methods can comprise detecting and analyzing an
emission of
fluorescent radiation from the live bacteria (e.g., from the DNA or RNA of the
live bacteria).
In some or other embodiments, non-viable bacteria (i.e., dead or dying
bacteria) can be
monitored according to the present methods by utilizing the fingerprint of
their altered DNA
or RNA.
[0197]
In some embodiments, monitoring the live bacteria in the water can
comprise monitoring the types of bacteria, the quantity of bacteria, or both
in the water. In
some embodiments, it may be of interest to determine if specific types of
bacteria are in the
61
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
water, and the opticoanalytical devices can be specifically configured to
detect different types
of bacteria based upon differences in their DNA or RNA "fingerprint." In other
embodiments, it may be more of interest to simply determine the number of
bacteria in the
water (i.e., the bacterial load), and the present methods can be used in this
regard as well by
configuring the opticoanalytical devices for less specific DNA or RNA
detection.
[0198]
Illustrative bactericidal treatments can include, for example, exposure
of the bacteria to ultraviolet light, electrocoagulation, ozonolysis, or
introduction of a
chemical biocide to the water. In particular, exposure to ultraviolet light
can be an especially
facile mechanism for killing bacteria, since a very rapid alteration of their
DNA or RNA can
occur upon exposure to ultraviolet light. Various illustrative bactericidal
treatments are
described in more detail in commonly owned United States Patent 7,332,094,
which is
incorporated herein by reference in its entirety, and in commonly owned United
States Patent
Applications 12/683,337 (U.S. Patent Application Publication 2011/0163046) and
12/683,343
(U.S. Patent Application Publication 2011/0166046), each of which is
incorporated herein by
reference in its entirety.
[0199]
In some embodiments, the methods can further comprise determining a
kill ratio for the bacteria that has been affected by the bactericidal
treatment. The kill ratio
can be determined, in some embodiments, by measuring the live bacterial load
before and
after a bactericidal treatment is performed. In some embodiments, the kill
ratio can be at
least about 75%. In other embodiments, the kill ratio can be at least about
80%, or at least
about 85%, or at least about 90%, or at least about 95%, or at least about
96%, or at least
about 97%, or at least about 98%, or at least about 99%. In some embodiments,
if a desired
kill ratio is not attained, the methods can further comprise repeating the
bactericidal treatment
or performing a different bactericidal treatment.
[0200] In other
embodiments, methods for monitoring bacteria can comprise:
monitoring live bacteria in a water source using an opticoanalytical device
that is in optical
communication with the water source; and after monitoring the live bacteria in
the water
source, exposing the water to a bactericidal treatment. In some embodiments,
the methods
can further comprise monitoring the live bacteria in the water using an
opticoanalytical
device that is in optical communication with the water after the bactericidal
treatment takes
place.
[0201]
In some embodiments, the present methods can further comprise
determining if the water is suitable for being introduced into a subterranean
formation. In
62
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
some embodiments, determining if the water is suitable can be based upon the
total number
of live bacteria in the water. For example, if an excessive number of live
bacteria are
detected, the water can be unsuitable. In some embodiments, determining if the
water is
suitable can be based upon the presence of certain types of bacteria in the
water, particularly
above a given bacterial load. For example, the presence of H2S-producing
bacteria in the
water can make the water unsuitable for being introduced into a subterranean
formation. In
addition, the mere presence of certain types of bacteria in the water can make
the water
unsuitable for being introduced into a subterranean formation.
[0202]
In some embodiments, the present methods can further comprise
forming a treatment fluid comprising the water and at least one additional
component; and
introducing the treatment fluid into a subterranean formation. In alternative
embodiments, a
water that is suitable for being introduced into subterranean formation can be
directly
introduced into a subterranean formation without forming a treatment fluid
(e.g., for a water
flooding operation). In some embodiments, the present methods can further
comprise
monitoring the treatment fluid in the subterranean formation using another
opticoanalytical
device located in the subterranean formation. In some embodiments, the
opticoanalytical
device can be used to monitor live bacteria in the treatment fluid and
determine if a
bactericidal treatment needs to be applied to the treatment fluid in the
subterranean formation.
In other embodiments, the opticoanalytical device in the subterranean
formation can be used
to monitor another characteristic of the treatment fluid according to the
embodiments
previously described herein.
[0203]
In some embodiments, methods for monitoring bacteria can comprise:
providing a treatment fluid comprising a base fluid and at least one
additional component;
monitoring live bacteria in the treatment fluid using an opticoanalytical
device that is in
optical communication with a flow pathway for transporting the treatment
fluid; and after
monitoring the live bacteria in the treatment fluid, introducing the treatment
fluid into a
subterranean formation after monitoring the live bacteria therein. In some
embodiments, the
treatment fluid can be flowing in the flow pathway while monitoring the
bacteria takes place.
In other embodiments, the treatment fluid can be static while monitoring the
bacteria.
[0204] In some
embodiments, the present methods can further comprise
determining a bactericidal treatment for the treatment fluid based upon the
types of bacteria
and the quantity of bacteria therein, as monitored using the opticoanalytical
device, and
performing the bactericidal treatment on the treatment fluid. In some
embodiments,
63
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
determining a bactericidal treatment for the treatment fluid can take place
automatically
under computer control. For example, based upon the types and number of
bacteria in the
treatment fluid, an artificial neural network can determine appropriate
bactericidal treatment
times, concentrations, and the like to predict how bacterial loads can be
reduced in a
treatment fluid. In some embodiments, the methods can further comprise
monitoring live
bacteria in the treatment fluid using an opticoanalytical device after
performing the
bactericidal treatment on the treatment fluid. Monitoring the bacteria in the
treatment fluid
after performing the bactericidal treatment can be used to assess the
effectiveness of the
bactericidal treatment prior to introducing the treatment fluid into the
subterranean formation.
[0205] In some
embodiments, the methods can further comprise monitoring
live bacteria in the treatment fluid while the treatment fluid is located in a
subterranean
formation by using another opticoanalytical device located in the subterranean
formation. In
some embodiments, the opticoanalytical device in the subterranean formation
can be used to
determine if bacterial loads in the subterranean formation have exceeded
desired levels. In
some embodiments, based upon the bacteria monitored in the subterranean
formation, the
present methods can further comprise adding a bactericidal agent to the
treatment fluid in the
subterranean formation.
[0206]
In some embodiments, methods for monitoring bacteria can comprise:
providing a treatment fluid comprising a base fluid and at least one
additional component;
introducing the treatment fluid into a subterranean formation; and monitoring
live bacteria in
the treatment fluid within the subterranean formation using an
opticoanalytical device located
therein. In some embodiments, the methods can further comprise adding a
bactericidal agent
to the treatment fluid within the subterranean formation. In some embodiments,
the methods
can further comprise monitoring live bacteria in the treatment fluid within
the subterranean
formation using the opticoanalytical device therein after adding the
bactericidal agent.
Monitoring of Fluid Streams
[0207]
More generally, methods described hereinabove using opticoanalytical
devices for monitoring treatment fluids and various components therein can be
extended to
monitoring the characteristics of fluid streams, particularly fluid streams
that are being
modified by an operator or under computer control, particularly remote
monitoring by an
operator or artificial neural network, in order to produce a desired effect in
the fluid stream.
As previously noted, fluid streams can be operatively linked to a great number
of industrial
processes, and the ability to monitor such fluids can be a significant process
advantage,
64
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
particularly when the monitoring can be conducted in-process. For example,
fluids can
change over time as a result of their use in an industrial process (or simply
degrade), and the
ability to rapidly monitor and respond to these changes can greatly improve
process
efficiency. Specifically, in some embodiments, opticoanalytical devices can be
used to
determine when a fluid needs to be replaced by monitoring its characteristics.
In other
embodiments, opticoanalytical devices can be used to determine when a fluid
needs to be
treated in order to adjust its characteristics, and in further embodiments,
the opticoanalytical
devices can be used to monitor an action taken to adjust the characteristics
of the fluid.
[0208]
In some embodiments, methods for monitoring a fluid can comprise:
providing a fluid in a fluid stream; and monitoring a characteristic of the
fluid using an
opticoanalytical device that is in optical communication with the fluid in the
fluid stream. In
some embodiments, the methods can further comprise determining if the
characteristic of the
fluid needs to be adjusted based upon an output of the opticoanalytical
device, and,
optionally, if the characteristic of the fluid needs to be adjusted,
performing an action on the
fluid in the fluid stream to adjust the characteristic of the fluid.
[0209]
In general, an action that can be taken on a fluid in order to adjust its
characteristics can include any chemical, physical, or biological process that
is undertaken in
order to adjust its properties. Any combination or chemical, physical and/or
biological
processes can be used to adjust the characteristics of the fluid. In some
embodiments, an
action that can be performed on a fluid can comprise adding at least one
component to the
fluid or increasing the concentration of the component in the fluid. For
example, in non-
limiting embodiments, an acid can be added or increased in concentration to
lower the pH of
a fluid, or a viscosifying agent can be added or increased in concentration to
modify the
rheological properties of a fluid. In some embodiments, an action that can be
performed on a
fluid can comprise removing at least one component from the fluid or reducing
the
concentration of the component in the fluid. For example, in non-limiting
embodiments, a
fluid can be subjected to ion exchange to remove ionic species therefrom, or a
filtration step
can be conducted to remove particulate matter from the fluid. In still other
embodiments, an
action that can be performed on a fluid can comprise exposing the fluid to a
bactericidal
treatment or another type of purification treatment known in the art. As
described above,
bacterial growth in fluids can present significant issues. Bactericidal
treatments can include
any of those set forth previously hereinabove. It is to be recognized that the
foregoing
examples of actions that can be performed on a fluid in order to adjust its
characteristics
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
should be considered illustrative in nature only, and one having ordinary
skill in the art will
be able to select an appropriate action to perform on a fluid in order to
affect its properties in
a desired way.
[0210]
In some embodiments, after an action has been performed on the fluid
in order to modify its characteristics, the fluid can again be monitored with
an
opticoanalytical device to determine if the action taken has had the desired
effect. In some
embodiments, the present methods can comprise monitoring a characteristic of
the fluid using
an opticoanalytical device that is in optical communication with the fluid in
the fluid stream,
after an action has been taken on the fluid to modify its characteristics.
Accordingly, if the
characteristic of the fluid has been modified in a desired way and returned to
an in-range
value, use of the fluid can continue. Likewise, if the characteristic of the
fluid has not been
returned to an in-range value, the action can again be performed on the fluid
or a different
action can be selected to be performed on the fluid.
[0211]
In some embodiments, various operations in the monitoring of the
characteristics of a fluid can take place automatically under computer
control. In some
embodiments, computer control can be used to determine if the characteristic
of the fluid
needs to be adjusted. In some embodiments, an action can be performed on the
fluid to adjust
the characteristic. In some embodiments, the action performed on the fluid can
take place
under computer control. For example, computer control can be used to assess an
out of range
characteristic in a fluid and determine an appropriate corrective course of
action. Thereafter,
computer control can be used to automatically carry out the action used for
adjusting the
characteristic of the fluid.
[0212]
In general, any type of fluid in a fluid stream can be monitored
according to the present embodiments. Fluids suitable for use in the present
embodiments
can include, for example, flowable solids, liquids and/or gases. In some
embodiments, the
fluid can be water or an aqueous fluid containing water. In other embodiments,
the fluid can
comprise an organic compound, specifically a hydrocarbon, an oil, a refined
component of
oil, or a petrochemical. Furthermore, the fluids streams can be operatively
coupled to any
type of process or used in any type of industrial setting. For example, in
some embodiments,
the fluid stream can comprise a water stream that is operatively coupled to a
cooling tower or
like heat transfer mechanism. In other embodiments, the fluid stream can be
located in a
refinery or chemical plant. When used in such locations, the fluid stream can
comprise a
coolant stream in some embodiments, a reactant feed stream in some
embodiments, or a
66
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
product feed stream in other embodiments. Thus, the present methods can be
used to confirm
that the correct materials are being supplied to and produced from an
industrial process, as
well as monitor background fluid use that is used in carrying out the process.
[0213]
In some embodiments, methods for monitoring a fluid can comprise:
providing a fluid in a fluid stream; monitoring a characteristic of the fluid
using an
opticoanalytical device that is in optical communication with the fluid in the
fluid stream;
determining if the characteristic of the fluid needs to be adjusted based upon
an output from
the opticoanalytical device; performing an action on the fluid in the fluid
stream so as to
adjust the characteristic; and after performing the action on the fluid in the
fluid stream,
monitoring the characteristic of the fluid using another opticoanalytical
device that is in
optical communication with the fluid in the fluid stream.
[0214]
In some embodiments, methods for monitoring water can comprise:
providing water in a fluid stream; performing an action on the water in the
fluid stream so as
to adjust a characteristic of the water; after performing the action on the
water in the fluid
stream, monitoring the characteristic of the water using an optico analytical
device that is in
optical communication with the water in the fluid stream; and determining if
the
characteristic of the water lies within a desired range. In some embodiments,
performing an
action on the water can comprise at least one action such as, for example,
adding at least one
component to the water or increasing the concentration of the component,
removing at least
one component from the water or reducing the concentration of the component,
exposing the
water to a bactericidal treatment or another purification treatment, and any
combination
thereof In some embodiments, the methods can further comprise repeating the
action on the
water or performing another action on the water, if the characteristic of the
water does not lie
in a desired range. In some embodiments, determining if the characteristic of
the water lies
within a desired range and repeating the action on the water and/or performing
another action
on the water can take place automatically under computer control.
[0215]
Although a number of industrial processes use and produce fluids, it is
believed that the present methods can be particularly beneficial in cooling
tower and refinery
applications. In both of these applications, it can be important to maintain
fluid integrity
during fluid input and output. In regard to refinery applications, the present
methods can be
applied to monitoring the fluid input and output of the material being refined
being refined.
For example, in some embodiments, opticoanalytical devices can be used to
monitor very
viscous fluids such as 30 gravity oil in order to monitor process integrity.
67
CA 02842676 2014-01-21
WO 2013/022549
PCT/US2012/046675
[0216]
Therefore, the present invention is well adapted to attain the ends and
advantages mentioned as well as those that are inherent therein. The
particular embodiments
disclosed above are illustrative only, as the present invention may be
modified and practiced
in different but equivalent manners apparent to those skilled in the art
having the benefit of
the teachings herein. Furthermore, no limitations are intended to the details
of construction
or design herein shown, other than as described in the claims below. It is
therefore evident
that the particular illustrative embodiments disclosed above may be altered,
combined, or
modified and all such variations are considered within the scope and spirit of
the present
invention. While compositions and methods are described in terms of
"comprising,"
"containing," or "including" various components or steps, the compositions and
methods can
also "consist essentially of" or "consist of" the various components and
steps. All numbers
and ranges disclosed above may vary by some amount. Whenever a numerical range
with a
lower limit and an upper limit is disclosed, any number and any included range
falling within
the range is specifically disclosed. In particular, every range of values (of
the form, "from
about a to about b," or, equivalently, "from approximately a to b," or,
equivalently, "from
approximately a-b") disclosed herein is to be understood to set forth every
number and range
encompassed within the broader range of values. Also, the terms in the claims
have their
plain, ordinary meaning unless otherwise explicitly and clearly defined by the
patentee.
Moreover, the indefinite articles "a" or "an," as used in the claims, are
defined herein to mean
one or more than one of the element that it introduces. If there is any
conflict in the usages of
a word or term in this specification and one or more patent or other documents
that may be
incorporated herein by reference, the definitions that are consistent with
this specification
should be adopted.
68
