Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEMS AND METHODS FOR MONITORING A PARAMETER OF A
SUBTERRANEAN FORMATION USING SWELLABLE MATERIALS
BACKGROUND
[0001] The present invention relates to monitoring subterranean formations and
more
particularly, systems and methods for monitoring a parameter of a subterranean
formation using
swellable materials.
[0002] Monitoring of reservoir behavior due to injection and production
processes is an
important element in optimizing the performance and economics of completion
and production
operations. Examples of these processes may include hydraulic fracturing,
water flooding,
steam flooding, miscible flooding, wellbore workover operations, remedial
treatments and many
other hydrocarbon production activities, as well as drill cutting injection,
CO2 sequestration,
produced water disposal, and various activities associated with hazardous
waste injection.
Because the changes in the reservoir may be difficult to resolve with surface
monitoring
technology, it may be desirable to emplace sensor instruments downhole at or
near the reservoir
depth in either special monitor wells or within the injection and production
wells.
[0003] Challenges with downhole measurements may include securely coupling
sensor
packages to the rock mass, isolating the packages as much as possible from
noise in the
wellbore, and providing cabling paths (if necessary) for transmitting data to
the surface. Sensors
may be deployed permanently or retrievably. Retrievable sensors packages are
often deployed
on wirelines, but also on coiled tubing or production tubing. Wireline
deployed arrays may use
clamp arms, magnets, or bow springs for coupling to the wellbore, whereas
coiled tubing or
tubing deployed arrays may have decentralizers and may be locked into the
wellbore through
friction and bending stresses. However, these types of deployment may be
susceptible to
coupling problems if the clamp arms do not fully extend, if magnets are placed
over scale or
other wellbore irregularities, or if the coiled tubing is not wedged against
the casing wall.
[0004] Permanent sensors may be cemented in place, but this can be a difficult
and
costly process for sizable sensor arrays. Successful deployments of large
sensor arrays may
have inserted the sensors coupled to tubing inside cemented casing with the
tubing then
cemented inside the casing. Attempts to directly place sensor arrays on the
outside of casing
have often been unsuccessful due to damage to the array during emplacement. A
successful
deployment of cemented sensors may remain susceptible to noise transferred
either up or down
the tubulars because of the affixation to the tubing or casing.
,
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FIGURES
[0005] Some specific exemplary embodiments of the disclosure may be understood
by
referring, in part, to the following description and the accompanying
drawings.
5 [0006] Figures 1A and 1B are partial schematic
cross-sectional views of a monitoring
system using swellable materials in accordance with an exemplary embodiment of
the present
invention.
[0007] Figure 2 is schematic perspective view of a monitoring system using
swellable
materials in accordance with an exemplary embodiment of the present invention.
10 [0008] Figure 3 is schematic perspective
view of a monitoring system using swellable
materials in accordance with an exemplary embodiment of the present invention.
[0009] Figures 4A, 4B, 4C and 4D are schematic cross-sectional views of a
monitoring
system using swellable materials in accordance with an exemplary embodiment of
the present
invention.
15 [0010] Figures 5A, 5B, 5C, 5D, 5E, 5F, 5G,
5H, 51 and 5J are schematic partial cross-
sectional views of a monitoring system using swellable materials in accordance
with an
exemplary embodiment of the present invention.
[0011] While embodiments of this disclosure have been depicted and described
and are
defined by reference to exemplary embodiments of the disclosure, such
references do not imply
20 a limitation on the disclosure, and no such limitation is to be inferred.
The subject matter
disclosed is capable of considerable modification, alteration, and equivalents
in form and
function, as will occur to those skilled in the pertinent art and having the
benefit of this
disclosure. The depicted and described embodiments of this disclosure are
examples only, and
not exhaustive of the scope of the disclosure.
25
[0012] The present invention relates to monitoring subterranean formations and
more SUMMARY
particularly, systems and methods for monitoring a parameter of a subterranean
formation using
30 swellable materials. [0013] In one aspect, a system for
monitoring a parameter of a subterranean formation
using swellable materials is disclosed. The system may include a sensor device
configured to
detect a parameter of a subterranean formation. The system may also include a
swellable
material configured to position the sensor device toward a surface of the
subterranean formation
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by swelling of the swellable material. The system may further include a
telescoping section
coupled to the sensor device and emplaced in the swellable material. The
telescoping section
may be configured to extend with the positioning of the sensor device.
[0014] In an embodiment, the sensor device is emplaced at least partially in
the
swellable material.
[0015] In an embodiment, the swellable material is further configured to
position the
sensor device against the surface of the subterranean formation by swelling.
[0016] In an embodiment, the sensor device is operative to communicate a
signal related
to the parameter of the subterranean formation.
[0017] In an embodiment, the telescoping section is configured to allow the
positioning
of the sensor device while the sensor device is operative to communicate a
signal related to the
parameter of the subterranean formation.
[0018] In an embodiment, the swellable material is on an exterior surface of a
tubular
body and is configured to position the sensor device away from the pipe by
swelling. In an
embodiment, the swellable material is further configured to reduce an effect
on the sensor
device of acoustic noise traveling along the tubular body.
[0019] In another aspect, a system for monitoring a parameter of a
subterranean
formation using swellable materials is disclosed. The system may include a
sensing tool
configured to detect a parameter of a subterranean formation. The sensing tool
may include a
generally tubular body. The system may also include a swellable material on an
exterior surface
of the generally tubular body. The swellable material may be configured to
anchor the sensing
tool in a position corresponding to a surface of the subterranean formation by
swelling of the
swellable material.
[0020] In an embodiment, the swellable material is further configured to
substantially
center the sensing tool between at least two opposing points on the surface of
the subterranean
formation.
[0021] In an embodiment, the swellable material comprises a plurality of
swellable
members disposed along the generally tubular body.
[0022] In an embodiment, the swellable material at least substantially
surrounds a length
of the generally tubular body.
[0023] In an embodiment, the swellable material is configured to anchor the
sensing tool
against the surface of the subterranean formation.
[0024] In an embodiment, the swellable material comprises a plurality of
swellable
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members disposed along the generally tubular body, wherein each swellable
member partially
surrounds a corresponding length of the generally tubular body.
[0025] In an embodiment, the swellable material longitudinally extends along a
length of
the generally tubular body.
[0026] In yet another aspect, a method for monitoring a parameter of a
subterranean
formation is disclosed. The method may include introducing a sensing tool to a
wellbore. The
sensing tool may include a generally tubular body and is configured to detect
a parameter of a
subterranean formation. The method may also include positioning the sensing
tool in a position
corresponding to a surface of the wellbore by swelling a swellable material.
The swellable
material may be disposed on an exterior surface of the generally tubular body.
The method may
also include detecting a parameter of a subterranean formation with the
sensing device.
[0027] In an embodiment, the positioning step comprises substantially
centering the
sensing tool between at least two opposing points on the surface of the
wellbore.
[0028] In an embodiment, the swellable material comprises a plurality of
swellable
members disposed along the generally tubular body.
[0029] In an embodiment, the swellable material at least substantially
surrounds a length
of the generally tubular body.
[0030] In an embodiment, the positioning step comprises anchoring the sensing
tool
against the surface of the wellbore.
[0031] In an embodiment, the swellable material longitudinally extends along a
length
of the generally tubular body.
[0032] In an embodiment, the sensing tool may be a part of the system
described above.
[0033] Certain embodiments of the present disclosed provide for a retractable
sensor
device and/or tool that may reenter a retracted state. Certain embodiments
provide for swell
controls that may be adapted for swelling and/or de-swelling swellable
materials.
[0034] The features and advantages of the present invention will be apparent
to those
skilled in the art. While numerous changes may be made by those skilled in the
art, such
changes are within the scope of the invention.
DETAILED DESCRIPTION
[0035] The present invention relates to monitoring subterranean formations and
more
particularly, systems and methods for monitoring a parameter of a subterranean
formation using
swellable materials.
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[0036] The systems, apparatuses and methods of the present disclosure may
allow for the
deployment of sensors in permanent, semi-permanent, and/or retrievable
applications with
minimal effect on the wellbore, superior coupling to the rock mass, minimal
vibrational degrees
of freedom, and significant isolation from the wellbore noise for those cases
where monitoring
of the reservoir is desirable. In certain embodiments, sensors may be at least
partially emplaced
within swell packers for direct coupling to tubulars with maximum isolation
from the rock mass
for cases where it is desirable to monitor the tubing deformation and/or flow
noise/activity
within the tubing. Such swell packers may be constructed of elastomers that
swell when
exposed to either hydrocarbons or water, depending upon the application, in
order to seal off and
isolate zones within the wellbore. The swell packers may provide coupling by
swelling and
forcing a sensor package against either a formation, a wellbore, or any rigid
contact point. In
certain embodiments, swellable materials may be implemented to centralize or
decentralize
sensors and/or sensor tools within a wellbore, depending on the desirability
of placing the
sensors and/or sensor tools in a central or decentralized position.
[0037] Illustrative embodiments of the present invention are described in
detail herein.
In the interest of clarity, not all features of an actual implementation may
be described in this
specification. It will of course be appreciated that in the development of any
such actual
embodiment, numerous implementation-specific decisions must be made to achieve
the specific
implementation goals, which will vary from one implementation to another.
Moreover, it will
be appreciated that such a development effort might be complex and time-
consuming, but would
nevertheless be a routine undertaking for those of ordinary skill in the art
having the benefit of
the present disclosure.
[0038] To facilitate a better understanding of the present invention, the
following
examples of certain embodiments are given. In no way should the following
examples be read
to limit, or define, the scope of the invention. Embodiments of the present
disclosure may be
applicable to horizontal, vertical, deviated, or otherwise nonlinear wellbores
in any type of
subterranean formation. Embodiments may be applicable to injection wells as
well as
production wells, including hydrocarbon wells. In addition well bore and well
casing
implementations, embodiments may be applicable for securely planting surface
instruments in
soft, crumbly ground.
[0039] Figure lA illustrates a system 100 where a tubular body 105 having an
axis 105A
is shown disposed in a wellbore 140 and adjacent to the wall 120. As depicted,
the tubular body
105 may be disposed in an uncased section of wellbore 140, but the tubular
body 105 may be
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disposed in a cased section or in near-surface ground in other embodiments.
The tubular body
105 may provide a conduit for formation fluids to travel therethrough. The
system 100 may
include a sensor package 110 fully or partially encased in a swellable element
115. The sensor
package 110 may be disposed at or near an outer boundary of the swellable
element 115.
[0040] It should be clearly understood that the principles of this disclosure
are not
limited to use with a particular sensor, sensor package, sensing device or
tool. Instead, the
principles of this disclosure are applicable to wide variety of devices, tools
and methods. Two
common sensors for reservoir monitoring are seismic and deformation sensors.
The sensor
package 110 may include, for example, a sonde, a geophone, an accelerometer, a
hydrophone, or
another device that detects ground motion due to either source shots (e.g.,
vertical seismic
profiling or crosswell surveys) or passive behavior such as microseismicity
and/or noise in both
the wellbore and the reservoir. Also, for example, the sensor package 110 may
include a sensor
for measuring deformation in the downhole environment, such as a tiltmeter
that measures the
gradient of displacement, or any instrument that measures differential
displacement in the
reservoir.
[0041] A line 135 may be coupled to the sensor package 110. The line 135 may
be any
one, or a combination, of a multi-conductor cable, a single conductor cable, a
fiber optic cable, a
fiber optic bundle, and a conduit or umbilical that contains cables, fiber
optics and control lines
to provide a hydraulic connection down hole. In certain embodiments, the line
135 may be a
wireline. In certain embodiments, the line 135 may be a means of placing the
sensor package
110 in the wellbore 140. In the alternative, the sensor package 110 and the
swellable material
may be coupled to the tubular body 105 and introduced into the wellbore 140
together. The line
135 may also be a means of communicating electrical signals, such as
indications of a parameter
associated with the subterranean formation, between the sensor package 110 and
a data
collection system and/or control system at remote location, such as the
earth's surface or a
subsea location. In certain embodiments, the line 135 may be a means of
communicating with
another well tool at another location in the wellbore 140 or another wellbore.
As depicted, a
portion of the line 135 may be encased in the swellable element 115. In
alternative
embodiments, the sensor package 110 may communicate via any type of telemetry,
such as
acoustic, pressure pulse, electromagnetic telemetry or any wireless means.
[0042] Referring next to Figure 1B, therein is depicted the system 100 of
Figure lA with
the swellable element 115 in an expanded configuration. When the swellable
element 115
comes in contact with an activating agent, the swellable element 115 expands
radially
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outwardly. As illustrated in Figure 1B, the swellable element 115 may come in
contact with the
wellbore wall 120 due to swelling. The sensor package 110 may include a
telescoping section
130 configured to extend outwardly toward the wall 120 along with the
expansion of the
swellable element 115 such that the swellable element 115 in effect pulls the
sensor package 110
toward the wall 120. In certain embodiments, the swellable element 115 may
force the sensor
package 110 to come into contact with the wall 120 and/or to partially or
completely protrude
into the wall 120. The telescoping section 130 may include any means by which
the sensor
package 110 may be displaced while maintaining connection with the portion of
the line 135
encased in the swellable element 115. For example, the telescoping member 130
may include
an extensible arm or an expandable cavity within the swellable element 115
that houses a length
of the line 135 with sufficient slack corresponding to the displacement of the
sensor package
110.
[0043] Certain embodiments may employ a single swellable element 115 as
depicted in
Figures lA and 1B. Other embodiments may employ multiple swellable elements.
Though not
shown in Figures 1A and 1B, one or more additional swellable elements may be
placed about
the tubing 105.
[0044] It is recognized that the swellable element 115 may be made of
different
materials, shapes, and sizes. For example, the swellable element 115 may be
deployed on
tubing with a symmetrical ring configuration. The swellable element 115 may
take an annular
form surrounding or partially surrounding the tubing 105, and may be any
elastomeric sleeve,
ring, or band suitable for expanding within a space between tubing 105 and an
outer tubing,
casing, or wellbore.
[0045] The term "swell" and similar terms (such as "swellable") are used
herein to
indicate an increase in volume of a material. Typically, this increase in
volume is due to
incorporation of molecular components of a fluid into the swellable material
itself, but other
swelling mechanisms or techniques may be used, if desired. The swellable
element 115 may
include one or more swellable materials that swell when contacted by an
activating agent, such
as an inorganic or organic fluid. In one embodiment, a swellable material may
be a material that
swells upon contact with and/or absorption of a hydrocarbon, such as oil. In
another
embodiment, a swellable material may be a material that swells upon contact
with and/or
absorption of an aqueous fluid. The hydrocarbon is absorbed into the swellable
material such
that the volume of the swellable material increases creating a radial
expansion of the swellable
material when positioned around a base pipe which creates a radially outward
directed force that
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may operate to radially extend telescoping members as described above. The
swellable material
may expand until its outer surface contacts the formation face in an open hole
completion or the
casing wall in a cased wellbore. The swellable material accordingly may
provide the force to
extend the telescoping member 130 of the sensor package 110 to the surface of
the formation
such as wellbore wall 120.
[0046] Suitable swellable elements include, but are not limited, to the
swellable packers
disclosed in U.S. Patent Nos. 3,385,367; 7,059,415; and 7,143,832; the entire
disclosures of
which are incorporated by reference. In certain embodiments, the swellable
element 115 may be
individually designed for the conditions anticipated for a particular case,
taking into account the
expected temperatures and pressures for example. Some exemplary swellable
materials may
include elastic polymers, such as EPDM rubber, styrene butadiene, natural
rubber, ethylene
propylene monomer rubber, ethylene-propylene-copolymer rubber, ethylene
propylene diene
monomer rubber, ethylene-propylene-diene terpolymer rubber, ethylene vinyl
acetate rubber,
hydrogenized acrylonitrile butadiene rubber, acrylonitrile butadiene rubber,
isoprene rubber,
butyl rubber, halogenated butyl rubber, brominated butyl rubber, chlorinated
butyl rubber,
chlorinated polyethylene, chloroprene rubber and polynorbornene.
[0047] As discussed above, these and other swellable materials may swell in
contact
with and by absorption of hydrocarbons so that the swellable material expands.
In one
embodiment, the rubber of the swellable materials may also have other
materials dissolved in or
in mechanical mixture therewith, such as fibers of cellulose. Additional
options may be rubber
in mechanical mixture with polyvinyl chloride, methyl methacrylate,
acrylonitrile, ethylacetate
or other polymers that expand in contact with oil. Other swellable materials
that behave in a
similar fashion with respect to hydrocarbon fluids or aqueous fluids also may
be suitable. Those
of ordinary skill in the art, with the benefit of this disclosure, will be
able to select an
appropriate swellable material for use in the present invention based on a
variety of factors,
including the desired swelling characteristics of the swellable material and
the environmental
conditions in which it is to be deployed.
[0048] In some embodiments, the swellable materials may be permeable to
certain fluids
but prevent particulate movement therethrough due to the porosity within the
swellable
materials. For example, the swellable material may have a pore size that is
sufficiently small to
prevent the passage of the sand therethrough but sufficiently large to allow
hydrocarbon fluid
production therethrough. For example, the swellable material may have a pore
size of less than
1 mm.
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[0049] As discussed above, the activating fluid/agent may comprise a
hydrocarbon fluid
or an aqueous fluid. In addition, an activating fluid may comprise additional
additives such as
weighting agents, acids, acid-generating compounds, and the like, or any other
additive that does
not adversely affect the activating fluid or swellable material with which it
may come into
contact. For instance, it may be desirable to include an acid and/or an acid-
generating
compound to at least partially degrade any filter cake that may be present
within a wellbore.
One of ordinary skill in the art, with the benefit of this disclosure, will
recognize that the
compatibility of any given additive should be tested to ensure that it does
not adversely affect
the performance of the activating fluid or the swellable material.
[0050] The activation agent may be introduced to the swellable material in a
variety of
ways. The activation agent may be injected into the wellbore or casing from a
source at the
surface. In other embodiments, the activation agent may be placed in the
wellbore or casing and
released on demand. In yet other embodiments, swelling of the swellable
material may be
delayed, if desired. For example, a membrane or coating may be on any or all
surfaces of the
material to thereby delay swelling of the material. The membrane or coating
could have a
slower rate of swelling, or a slower rate of diffusion of fluid through the
membrane or coating,
in order to delay swelling of the material. The membrane or coating could have
reduced
permeability or could break down in response to exposure to certain amounts of
time and/or
certain temperatures. Suitable techniques and arrangements for delaying
swelling of a swellable
material are described in U.S. Patent Nos. 7,143,832 and 7,562,704, the entire
disclosures of
which are incorporated herein by reference.
[0051] The swellable materials of certain embodiments may be shrinkable or may
be
distintegratable. A deactivating fluid/agent, for example, may comprise a salt
compound that
would cause the swelled materials to contract by way of osmosis. A
disintegrating fluid/agent,
for example, may comprise any chemical adapted to chemically destroy the
swellable material.
In either case, the shrinking or disintegrating of the swellable material
allows for the
unanchoring of the sensor device or tool.
[0052] In alternative embodiments, the system 100 may comprise a sampling
package
(not shown) in lieu of or in addition to the sensor package 110. The sampling
package may
comprise an extendable straw or functional equivalent. When the swellable
element 115 comes
in contact with an activating agent, the swellable element 115 expands
radially outwardly and
may seal about an area of the wellbore wall 120. The sampling package, coming
into contact
with the formation, may facilitate fluid flowing from the formation such that
the fluid may be
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monitored by the sensors. Alternatively or additionally, the fluid from the
formation at that spot
may be used as a fluid power source. Alternatively or additionally, the
sampling package,
coming into contact with the formation, may obtain a sample from the location.
Then, by way
of the de-swelling processes disclosed herein, the system 100 may be retracted
from the
wellbore 120 and the sample may be recovered from the sampling package.
[0053] Figure 2 illustrates a system 200 where a swellable element 215
provides for
symmetric instrument tool clamping within a borehole or casing. A tool 205 may
be or include
a sensor device, a microseismic array tool, or any other tool for which
vibrations degrade its
fidelity. As depicted, the tool 205 may comprise a tubular body and may be
disposed in an
uncased section of the wellbore 240. Alternatively, the tool 205 may be
disposed in a cased
wellbore. Certain embodiments may include umbilical lines, wirelines, or tubes
to the surface
that could be incorporated to provide for positioning and/or monitoring the
tool 205 and
downhole sensors, for electrically activated controls of subsurface equipment,
for injecting
chemicals, or any combination thereof In alternative embodiments,
communication with the
tool 205 may be achieved via any type of telemetry, such as acoustic, pressure
pulse or
electromagnetic telemetry.
[0054] One or more swellable elements 215 may be coupled to the tool 205 and
may be
configured to expand to anchor symmetrically, or substantially symmetrically,
the tool 205
against a wall 220 of the wellbore or casing. For example, the swellable
elements 215 may be
configured to swell, due to contact with an activation agent, to a position
210. As illustrated by
the position 210, the swellable elements 215 may come in contact with the wall
220 upon
expansion.
[0055] The swellable elements 215 may be any elastomeric sleeve, band, ring,
or other
annular form surrounding or partially surrounding the tubing 205 and suitable
for expanding
between the tool 205 and wall 220, as long as the swellable elements 215
anchor the tool 205 in
a symmetrical or substantially symmetrical manner. For example, when a
configuration of the
swellable elements 215 fully ring the tool 205, the tool 205 may become well-
centered in the
wellbore or casing so that microseismic energy may reach the tool 205
substantially equally well
from all sides. In certain embodiments, a symmetric, or substantially
symmetric, system similar
to system 200 may surround a geophone planted in a shallow surface borehole to
suppress
decoupled oscillations of the instrument.
[0056] The areal contact of the swellable elements 215 with the tool 205
provides
stiffening and allows shifting of modal vibrations to higher frequencies above
the range of the
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microseisms or other sources that are being monitored. Because they expand
into available
space, the swelling elements themselves are very well suited for use in
irregular boreholes as
tool contact is necessarily hit-or-miss along the length of the tool in such
settings. Similar
swelling elements applied to surface-based acquisition sensors (e.g., shallow
borehole
geophones or tiltmeters) allow firm emplacement that, in contrast to permanent
cementation,
allows subsequent retrieval and reuse. In certain embodiments, the swellable
elements 215 may
form seals in the wellbore 240 by swelling. The swellable elements 215
accordingly may
prevent fluid from flowing outside of an interval along the body of the tool
205. In certain
embodiments, the swellable elements 215 may be configured to effectively
isolate the entire, or
nearly the entire, body of the tool 205, as desired.
[0057] Figure 3 illustrates a system 300 where a swellable element 315
provides for
asymmetric instrument tool clamping within a wellbore 340. One or more
swellable elements
315 may be coupled to the tool 305 in an asymmetric manner so that the
swellable elements 315
anchor the tool 305 in an asymmetrical manner. In such a configuration, the
tool 305 may be
pushed up against a side 320 of the wellbore or casing, where the tool 305 may
receive
microseismic energy via direct contact. The swellable elements 315 may push
the tool against
the borehole wall more uniformly and firmly along its length, as compared to
conventional
approaches.
[0058] It should be understood, in light of this disclosure, that a number of
combinations
of tubing and/or wireline run with encased, ring, or partial ring deployment
may have
advantages that can be exploited for a given monitoring situation, as for
example to shield
against noise, temperature, or wellbore chemistry and to appropriately couple
for what is
actually being monitored.
[0059] Figures 4A-4D illustrate a system 400 run on wireline using an
eccentric swell
packer for clamping a tool 405. A swellable element 415 may run along a length
of the tool 405
to provide for asymmetric instrument tool clamping within a wellbore or
casing. The swellable
element 415 may fit along a holder 410. Figures 4A and 4B depict the swellable
element 415
prior to activation. Figures 4C and 4D depict the swellable element 415 in an
expanded position
after contact with an activation agent. The expansion may cause the swellable
element 415 and
the tool 405 to contact the wall 420 of the wellbore or casing.
[0060] Figures 5A-5H illustrate a system 500 where a tubular body 505 is shown
disposed in a wellbore or casing 540 and adjacent to the wall 575. Figures 5A
and 5B
respectively illustrate partial side and perspectives views of the system 500
in a retracted state.
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Figures 5C and 5D respectively illustrate partial side and perspectives views
of the system 500
in an expanded state. The tubular body 505 may be encircled by an inner
arrangement 510 and
an outer arrangement 515. The tubular body 505 may be provided with ribbing
555 or other
means configured to prevent rotation of the inner arrangement 510 about the
tubular body 505.
The tubular body 505 may be provided with one or more flanges 545 proximate to
the inner
arrangement 510 and configured to anchor the inner arrangement 510 so as to
prevent axial
movement with respect to the tubular body 505.
[0061] The inner arrangement 510 and the outer arrangement 515 may
respectively
include components 510A and 515A, disposed in a generally circular, annular
and/or cylindrical
arrangement. For example, as depicted in the cross-sectional representations
in Figures 5B and
5D, one or more components 510A, 515A generally form partial sectors or arcs.
The
components 510A, 515A may be solid or hollow pieces and may be made of metal,
composite
or another type of suitable material.
[0062] One or more sensor packages 550 may be coupled to the outer arrangement
515.
Each sensor package 550 may have at least a portion extending into a component
515A. In
certain embodiments, one or more sensor packages may be coupled to the inner
arrangement
505. In certain embodiments, one or more sensor packages may be coupled to
both the inner
arrangement 505 and the outer arrangement 515. In the latter embodiment, the
sensor packages
may be configured for noise-canceling in order to attenuate tubular-borne
noise.
[0063] As depicted, the inner arrangement 510 and the outer arrangement 515
may be
coupled by way of one or more struts 520. The struts 520 may be configured to
have a degree of
freedom and, for example, may be swivably attached to one or both of the inner
arrangement
510 and the outer arrangement 515. It may be preferable that a swivel
attachment be associated
with either one or the other of the inner arrangement 510 and the outer
arrangement 515, so that
both may maintain a stable configuration during insertion into or retrieval
from the borehole. In
one exemplary embodiment, the swivel attachment may be of a hinge type and may
have a
vertical length around an axis of rotation. In certain embodiments, the swivel
attachment may
include paths for electrical signal lines.
[0064] Adjacent components 510A, 515A may be coupled to each other. For
example
without limitation, each component 510A, 515A may be coupled to an adjacent
component
510A, 515A via a mandrel and/or an expansion sleeve. As depicted, adjacent
components 510A
of the inner arrangement 510 are coupled via expansion sleeves 525. Adjacent
components
515A of the outer arrangement 515 are coupled via expansion sleeves 530. The
expansion
CA 02810332 2013-03-04
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sleeves 525 and 530 may partially encase, surround or otherwise wrap around
portions of
adjacent circular components 510A and 515A, thereby aiding the generally
circular alignment of
the components 510A and 515A. The expansion sleeves 525 and 530 may be made of
metal,
composite or another type of suitable material.
[0065] Figures 5E-5J illustrate one example of an expansion sleeve 530 about
adjacent
circular components 515A. Figure 5E illustrates an unexpanded state, while
Figure 5F
illustrates an expanded state. The adjacent components 510A may be configured
to allow a
region 535 between them when not flush. Swellable elements may be disposed in
the region
535. In one example, elastomer 530A may be disposed in the region 535 with
swell controls
560. Though not depicted, an expansion sleeve 525 and adjacent circular
components 510A
may be similarly configured. The swellable elements may be configured to
expand generally
tangentially to the inner arrangement 510 so that the inner arrangement 510
expands generally
tangentially, as opposed to radially. Thus, the swellable elements, in
conjunction with other
elements of system 500, provide a mechanism for the system 500 to detach from
the tubular
body.
[0066] As depicted in Figure 5G, the swell controls 560 may include fluid
and/or
electrical lines 565 that may be configured to convey activation agent and/or
activate valves
570. The valve 570 may include one or more reservoirs and may be operable to
disperse the
activation agent to the swellable materials 515A. By this or similar means,
the swell controls
560 may be adapted for swelling the swellable materials 515A so that the
system 500 may
detach from the tubular body.
[0067] In addition to detachment, the swellable elements may similarly provide
a
mechanism for reattachment. For example, it may be preferable for the
swellable elements to be
water-swellable. A deswelling agent may include salt to extract water from a
water-swellable
material by osmosis. The electrical lines may later be used to expose the
swellable elements to
a deswelling agent in order to shrink the swellable material, thereby
transitioning the tool to a
retracted state that would allow for tool retrieval. Thus, the swell controls
560 may be adapted
for de-swelling the swellable materials 515A.
[0068] Figures 5H and 51 show diagrams of one exemplary embodiment of a valve
570.
By way of example without limitation, the valve 570 may include a deswelling
agent reservoir
572 and/or a swelling agent reservoir 574. A slide 576 may include ports that
may be
selectively aligned with a deswelling agent reservoir 572 and/or a swelling
agent reservoir 574.
For example, Figure 51 depicts a view of the slide where ports 578A are shown
in an open state
CA 02810332 2013-03-04
14
and in aligned with a reservoir port. Ports 578B are shown in a closed state
and not aligned with
a reservoir port. The valve 570 may be configured with the slide 576 to allow
for the controlled
feed of an agent to the swellable material. The slide 576 may be activated by
hydraulics or an
electrical device such as an electromagnet on either end. In alternative
embodiments, one or
both of the valve 570 and the slide 576 may be adapted so the ports of the
slide may be
selectively aligned with the ports of a reservoir by rotation, rather than
lateral motion of the slide
576 indicated in Figure 5H. For example, the slide 576 may have a disk form
with ports that
may be rotated about a center.
[0069] Figure 5J illustrates a mandrel 525A that may be used in the
alternative or in
addition to expansion sleeves to couple two or more adjacent circular
components 510A and
515A. The mandrel 525A may be used as a one- or two-ended piston to prevent or
minimize
lateral expansion such that expansion is directed along an axis of the
mandrel. In certain
embodiments, secondary mandrels in the outer arrangement 515 may be preferred
in order to
shift the centerpoint of the inner arrangement 510 as the tubular body 505 may
not always be
well-centered in the borehole 540.
[0070] Swellable elements may be included with the mandrels 525A. As depicted
in
Figure 5J, a mandrel 525A may include an outer body 525B that at least
partially surrounds an
elastomer material 525C. The elastomer material 525C is shown in an at least
partially
expanded state. The outer body 5258 may comprise metal, a composite, or any
other suitable
material. Although the mandrel 525A is depicted as having a particular shape,
it should be
understood that the shape and implementation of the mandrel 525A may be
subject to
considerable modification, as would be understood by one of ordinary skill in
the art having the
benefit of this disclosure.
[0071] Thus, in the expanded state, the system 500 allows sensor packages to
be
deployed in a state that has no direct physical contact or intermediate
structural contact with the
tubular body. Having the tool placed against the side of the borehole with no
direct
solid-to-solid contact with the tubular body, the sensor packages are afforded
a degree of
acoustic isolation from acoustics that may otherwise be transferred via the
tubular body.
Further, the system 500 provides a safety margin such that the tool may be
spared from sharp,
high-force, or uncontrolled movements that could endanger tubing, wiring, the
borehole wall, or
the tool. The generally circular outer arrangement 515 provides a perimeter
that may allow for
positioning while maintaining tolerance for irregularities that may be
encountered in the surface
of the borehole. Although system 500 is depicted with four circular components
and four sensor
CA 02810332 2013-03-04
15
packages in the outer arrangement 515, and four circular components in the
inner arrangement
510, it should be understood that other embodiments may include a different
number and
combination of circular components and sensor packages.
[0072] In another embodiment, the inner arrangement 510 may be coupled to
spring-
powered extensions released to point inwards to the tubular body 505 in order
to "measure" the
radial distance between the inner arrangement 510 and the tubular body 505 at
three or more
points. As the spring-powered extensions increasingly extend, they may
restrict the flow of
swelling agent into their respective components 510A, thereby allowing those
swellable sections
nearest the tubular to be expanded outwards more rapidly than those farther
away, and thereby
centering the inner arrangement 510 at a uniform distance from the tubular
body 505. Once
deployed, the extensions may be retracted into the inner arrangement 510.
[0073] Certain embodiments of the present disclosure may provide a simpler,
cheaper,
and easier means of coupling sensors to a formation or tubing/casing that are
likely to provide
much surer coupling. Most previous sensor deployments have used cement
coupling (generally
for permanent deployments), mechanical coupling such as clamp arms and bow
springs (for
both permanent and retrievable applications), magnetic coupling (retrievable
applications), or
even uncoupled deployments (e.g., sensors attached to tubing run inside of
casing) that rely on
friction and bending stresses. Methods and systems of the present disclosure
may eliminate the
need for mechanical clamp arms (which may have leak issues with seals and high
temperature),
bow springs (which may have poor high frequency response and resonances),
magnets (which
may have limited coupling and resonances), or cementing. Methods and systems
of the present
disclosure may also improve omnidirectional array fidelity, even for
retrievable operations and
settings where the swelling elements may be subsequently de-swelled, detached
or torn off to
facilitate tool retrieval or repositioning.
[0074] Certain embodiments of the present disclosure may allow for long-term
emplacement in difficult open-hole environments without permanently cementing
an instrument
in place. This may simplify operations and may allow for retrievable sensor
devices if
difficulties occur during emplacement. This may avoid the situation in open-
hole environments
where mechanical arms or bowsprings can sink into soft materials in the hole
and cause poor
tool coupling. Such a situation can occur in shales and many shallow boreholes
where sensors
would otherwise have to be cemented in permanently to obtain good coupling.
[0075] Certain embodiments may allow for improved signal fidelity for
microseismic
monitoring of hydraulic fractures by ensuring better coupling compared to
clamp arms, bow
CA 02810332 2013-03-04
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spring, magnets, or other emplacement methods, thus attenuating or eliminating
longitudinal
tool vibrations that degrade the recording fidelity of elastic body wave
motion parallel to a tool
axis. In certain embodiments, swelling elements may effectively dampen
acoustic noise
generated by flow in production tubulars as well as noise received via the
tubulars. The
swelling elements may even yield sensor isolation from the tubulars even
though swellable
elements are in contact with both. Additionally, certain embodiments may allow
for securely
planting surface instruments in soft, crumbly ground.
[0076] Certain embodiments may remove directional bias of recorded signals by
emplacing sensors in the center of a borehole with equal response from all
directions, as
opposed to a likely higher fidelity on the side of the borehole on which it is
deployed when
clamped or cemented. Certain embodiments may eliminate the need for a nearby
vertical
observation well by allowing for installation of tools in the
injection/production well with good
coupling and a degree of noise suppression from tubing activities.
[0077] Certain embodiments may be used for time-lapse seismic monitoring
and/or time-
lapse deformation monitoring throughout the life of the reservoir for more
permanent
installations. The time-lapse seismic application requires a source on either
the surface or in a
nearby well; time-lapse deformation only requires continuous measurements of
tilt or other
deformation parameters. For emplacement of tiltmeters, geophones, or other
sensors in shallow
boreholes, certain embodiments provide a fast, easy method to deploy sensors,
potentially
allowing them to stabilize much faster¨which translates to a shorter lead time
for monitoring.
[0078] Even though the figures depict embodiments of the present disclosure in
a
horizontal section of a wellbore, it should be understood by those skilled in
the art that
embodiments of the present disclosure are well suited for use in deviated or
vertical wellbores or
casings. Accordingly, it should be understood by those skilled in the art that
the use of
directional terms such as above, below, upper, lower, upward, downward and the
like are used
in relation to the illustrative embodiments as they are depicted in the
figures, the upward
direction being toward the top of the corresponding figure and the downward
direction being
toward the bottom of the corresponding figure. Additionally, as discussed
above, embodiments
of the present disclosure may be implemented in cased or uncased wellbores,
even though only
uncased wellbores are depicted in the figures.
[0079] 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
CA 02810332 2013-03-04
17
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 or modified and all
such variations are
considered within the scope of the present invention. Also, the terms in the
claims have their
plain, ordinary meaning unless otherwise explicitly and clearly defined by the
patentee. 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.
