Note: Descriptions are shown in the official language in which they were submitted.
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DOWNHOLE ARRAY AND ASSEMBLY THEREOF
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to downhole arrays configured for use in
wells, such as oil and gas wells.
Description of Related Art
[0002] It is often desirable to control and or perform operations, such as
chemical injection, dewaterization, or gas lifting applications, on a well.
Furthermore, it
is also often desirable to determine characteristics of a well or
characteristics of fluid to
be produced from a well. For example, it is often desirable to gather
information, such
as reservoir pressure and temperature, about the fluid-producing or
"production interval"
of a well. Such information can, then, be used to optimize the production from
the well.
In directionally-drilled oil and gas wells, commonly referred to as
"horizontal" wells, the
thickness and geology of the hydrocarbon-bearing reservoir can vary greatly
over the
length of the production interval. The importance of these variations is
compounded
when producing highly viscous oils with high specific gravities, commonly
referred to as
"heavy oils," which are often recovered using steam-assisted, gravity-drainage
(SAGD)
techniques. For example, knowing reservoir pressures and temperatures at
locations
along the production interval allows specific completions and production
simulation
programs to be designed for particular wells to optimize production from the
wells.
[0003] However, current technologies for determining the reservoir pressures
and temperatures along production intervals of wells are expensive and often
unreliable.
For example, positioning multiple pressure and temperature sensors, as well as
other
components, such as flow control devices, within a well often creates
restrictions in the
well. Moreover, pressure and temperature sensors are fragile in nature and, to
inhibit
failures, must be protected from the often extreme environments found in
wells.
Furthermore, data derived from the sensors must be correlated with the
locations of the
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sensors within the production interval for the data to be of any value.
Accordingly,
to inhibit the sensors or other such components from drifting from their
desired
locations within a well, the sensors often must be banded, clamped, strapped,
and/or otherwise attached to the well casing. It should be noted that
deploying
multiple sensors or other such components within a production interval of a
well
using conventional techniques often requires multiple runs or trips down the
well.
Each run adds to the unproductive cost of operating or completing the well.
Moreover, retrieving the sensors from the well interrupts or at least hinders
operation of the well.
[0004] There are many designs of downhole component arrays well known
in the art, however, considerable shortcomings remain.
BRIEF SUMMARY OF THE INVENTION
[0005] In one aspect of the present invention, a downhole array is provided.
The downhole array includes first and second canisters, a component disposed
in
each of the canisters, a first conduit extending to the first canister, and a
second
conduit extending to the second canister such that the canisters are spaced
apart
from one another by a predetermined distance.
[0006] In another aspect, the present invention provides a downhole array
assembly. The downhole array assembly includes a tubing string, first and
second canisters disposed within the tubing string, and first and second
couplings
corresponding to the first and second canisters, each coupling attaching a
corresponding one of the canisters to the tubing string. The downhole array
assembly further includes a component disposed in each of the canisters, a
first
conduit extending the first canister, and a second conduit extending to the
second
canister. The canisters are spaced apart from one another by a predetermined
distance.
[0007] In yet another aspect of the present invention, a well is provided.
The well includes a wellhead, a borehole (cased or uncased) extending from the
wellhead into a productive interval, and a tubing string disposed in the
borehole
and extending from the wellhead into the productive interval. The well further
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includes first and second canisters disposed within the tubing string, first
and
second couplings corresponding to the first and second canisters, each of the
couplings attaching a corresponding canister to the tubing string, a component
disposed in each of the canisters, a first conduit extending from the wellhead
to
the first canister, and a second conduit extending from the wellhead to the
second
canister. The canisters are spaced apart from one another by a predetermined
distance.
[0008] The present invention provides significant advantages, including: (1)
providing a way to deploy components in a productive interval of a well
without
unduly restricting the well; (2) providing a way to protect components from
the
extreme environments found in wells; (3) providing a way to deploy components
in
a productive interval of a well without banding, clamping, or strapping the
components to a well casing; and (4) providing a way to deploy a plurality of
components in a productive interval of a well in one run or trip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The novel features of the invention are set forth in the appended
claims. However, the invention itself, as well as a preferred mode of use, and
further objectives and advantages thereof, will best be understood by
reference to
the following detailed description when read in conjunction with the
accompanying
drawings, in which the leftmost significant digit(s) in the reference numerals
denote(s) the first figure in which the respective reference numerals appear,
wherein:
[0010] Figure 1 is a side, sectional view of an illustrative embodiment of a
downhole array assembly operably associated with a horizontal well;
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[0011] Figure 2 is a stylized, schematic view of a portion of the downhole
array assembly of Figure 1, illustrating predetermined spacing between
canisters of the
array assembly;
[0012] Figure 3 is a stylized, schematic view of a portion of the downhole
array assembly of Figure 1, illustrating exemplary conduit configurations of
the array
assembly;
[0013] Figure 4 is a stylized, partial cross-sectional view of a portion of
the
downhole array assembly of Figure 1, depicting an illustrative attachment
between a
canister and a tubing string of the array assembly;
[0014] Figures 5-8 are cross-sectional views of a portion of the downhole
array assembly of Figure 1, depicting various illustrative coupling
embodiments for
attaching a canister and a tubing string of the array assembly;
[0015] Figures 9 and 10 are stylized, partial cross-sectional views of a
portion
of the downhole array assembly of Figure 1, depicting illustrative embodiments
of a
canister of the array assembly;
[0016] Figure 11 is a perspective view of an illustrative embodiment of the
array assembly of Figure 1 in a sensor array configuration;
[0017] Figures 12-13 are perspective views of alternative, illustrative
embodiments of the array assembly of Figure 1 in a sensor array configuration;
and
[0018] Figure 14 is a perspective view of an illustrative embodiment of a
canister in the sensor array configuration.
[0019] While the invention is susceptible to various modifications and
alternative forms, specific embodiments thereof have been shown by way of
example in
the drawings and are herein described in detail. It should be understood,
however, that
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the description herein of specific embodiments is not intended to limit the
invention to
the particular forms disclosed, but on the contrary, the intention is to cover
all
modifications, equivalents, and alternatives falling within the scope of the
invention as
defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Illustrative embodiments of the invention are described below. In the
interest of clarity, not all features of an actual implementation are
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
developer's specific goals, such as compliance with system-related and
business-
related constraints, 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 this disclosure.
[0021] A downhole array includes a plurality of canisters that are linked or
interconnected via a single conduit or a plurality of conduits. The single
conduit or
plurality of conduits may, in various embodiments, comprise, for example,
hydraulic,
optical, and/or electrical conductors. The plurality of canisters is not
required to be
linked in series, as a conduit of the plurality of conduits may bypass one or
more
canisters. The canisters of the plurality of canisters are spaced away from
one another
by one or more predetermined distances. Preferably, the one or more conduits
define
the canister spacing.
[0022] In one embodiment, the array is disposed within and attached to a
tubing string to form an array assembly, such that the installation of the
array in the
tubing string does not appreciably or substantially affect the structural
integrity of the
tubing string. The tubing string is contiguous proximate the plurality of
canisters, such
that the only breeches in the tubing string proximate the plurality of
canisters are
openings used to attach the plurality of canisters to the tubing string and to
allow
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communication of reservoir fluids into the plurality of canisters. In
embodiments that
include a tubing string, each canister of the plurality of canisters is
preferably located
within the tubing string using a detection device external to the tubing
string. The
location of each canister with respect to the tubing string is fixed using an
anchoring
means.
[0023] The present array is particularly useful in well completion and in
reservoir monitoring and control. For example, in well completion
applications, the
downhole array can, in various embodiments, facilitate packer setting, zonal
isolation,
chemical injection, dewaterization, gas lift, and/or other such activities.
The downhole
array can be configured into a sensor array by the addition of one or more
sensors in
the canisters of the array. The sensor array can provide sensory information
that is
useful in determining pressure, acoustic, and temperature characteristics of a
reservoir;
fluid sampling; fluid testing; and/or other such activities relating to
reservoir monitoring
and control. Such sensory information may be gathered in real time or stored
with the
aid of memory devices.
[0024] Figure 1 depicts a stylized, side, sectional view of a downhole array
assembly 101 operably associated with a directionally-drilled or "horizontal"
well 103. It
should be noted, however, that downhole array assembly 101 may be operably
associated with wells other than horizontal wells, such as wells known as
"vertical"
wells. In the illustrated embodiment, downhole array assembly 101 extends from
a
wellhead 105 proximate a surface 107 of the earth to a location in well 103
within a
productive zone or interval 109. As is described in greater detail herein,
downhole array
assembly 101 of the illustrated embodiment comprises a downhole array 111
including
a plurality of canisters 113, 115, 117, and 119 disposed within a contiguous
tubing
string 121. It should be noted, however, that downhole array 111 may include
any
suitable number of canisters, such as canisters 113, 115, 117, and 119.
Preferably,
tubing string 121 is of the type commonly referred to in the art as "coiled
tubing," and
tubing string 121 is contiguous in the zone proximate canisters 113, 115, 117,
and 119,
as discussed above. In some embodiments, however, tubing string 121 is
omitted, as
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discussed in greater detail herein with regard to Figure 14. One or more
conduits 123
couple the plurality of canisters. In the illustrated embodiment, the one or
more
conduits 123 pass through wellhead 105 so that the one or more conduits can be
coupled with ancillary equipment. For example, in one embodiment, the one or
more
conduits 123 provide a means for conducting sensory information from sensors
operably associated with the canisters to a location proximate wellhead 105
and provide
a means for conducting power to sensors of downhole array 111. Moreover,
downhole
array 111 may be used as a selective production string to retrieve fluids from
productive
zone 109 of well 103.
[0025] Figure 2 is a stylized, schematic view, referenced in Figure 1, of
canisters 113 and 115 disposed in tubing string 121 and coupled by conduit
123.
Canisters 113 and 115 are separated by a predetermined distance L to provide a
desired distance between locations within productive interval 109 (shown in
Figure 1). It
should be noted, however, that other canisters may be separated by
predetermined
distances other than predetermined distance L or other canisters may be
separated by
the same predetermined distance L.
[0026] As discussed above, the plurality of canisters 113, 115, 117, and 119
(shown in Figure 1) may be interconnected, either in series or not in series,
by one
conduit, such as conduit 123 (shown in Figures 1 and 2), or by more than one
conduit.
For example, in the stylized, schematic view of Figure 3, referenced in Figure
1,
canisters 115, 117, and 119 are interconnected in the aggregate by conduits
301, 303,
and 305, rather than by single conduit 123. In the illustrated embodiment,
conduit 301
extends to canisters 117 and 119 but not to canister 115. Conduit 303 extends
to
canisters 115 and 117 but not to canister 119. Conduit 305 extends to
canisters 115
and 119 but not to canister 117. It should be noted that the configuration
depicted in
Figure 3 is merely exemplary of the multitude of configurations that would be
evident to
one of ordinary skill in the art having the benefit of the present disclosure,
each of which
is deemed to be within the scope of the present invention.
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[0027] Figure 4 provides a stylized, schematic view, referenced in Figure 1,
of
canister 117 disposed in tubing string 121 with conduit 123 extending through
canister
117. Note that tubing string 121 is shown in cross-section. Canister 117 is
attached to
tubing string 121 by a coupling 401 to fix the location of canister 117 with
respect to
tubing string 121. Couplings corresponding to coupling 401 also attach
canisters 113,
115, and 119 (shown in Figure 1) to tubing string 121. The scope of the
present
invention encompasses any suitable means for attaching canister 117, as well
as the
other canisters of downhole array 111, such as canisters 113, 115, and 119, to
tubing
string 121. In some embodiments, coupling 401 defines a port, represented by
arrow
403, providing fluid communication into canister 117, and such embodiments of
coupling 401 are discussed in greater detail herein with respect to Figures 5-
8. Canister
117 provides pressure integral seals through which conduit 123 passes or to
which
conduit 123 is connected.
[0028] Figures 5-8 depict cross-sectional views of various embodiments of
coupling 401 that may be employed with any tubing string and canister of
downhole
array assembly 101. Referring to Figure 5, tubing string 121 defines a
threaded
opening 501 and canister 117 defines a corresponding threaded opening 503. A
threaded plug 505 is threadedly engaged with threaded opening 501 and threaded
opening 503 to provide a pressure seal between the inside of canister 117 and
the
inside of tubing string 121. In the illustrated embodiment, threaded plug 505
defines a
port 507 that provides communication of reservoir fluids from outside tubing
string 121
to the inside of canister 117. In the illustrated embodiment, reservoir fluids
are allowed
to enter tubing string 121 and an annulus 509 between tubing string 121 and
canister
117.
[0029] Figure 6 depicts an alternative embodiment of coupling 401. Tubing
string 121 defines an opening 601 and canister 117 defines an opening 603 that
is
smaller than opening 601. Canister 117 is attached to tubing string 121 by a
weldment
605 that extends contiguously about opening 601 to provide a pressure seal
between
the inside of canister 117 and the outside of tubing string 121. Opening 603
provides a
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port 607 for communication of reservoir fluids from outside tubing string 121
to the
inside of canister 117. In the illustrated embodiment, weldment 605 further
provides a
pressure seal between the exterior of tubing string 121 and the interior of
tubing string
121, thus inhibiting reservoir fluids from entering tubing string 121 except
into canister
117.
[0030] Figure 7 depicts yet another embodiment of coupling 401. Tubing
string 121 defines an opening 701 and canister 117 defines an opening 703. A
rivet-
style fastener 705 extends between tubing string 121 and canister 117 to
fasten canister
117 to tubing string 121. Rivet-style fastener 705 defines a port 707 for
communication
of reservoir fluids from outside tubing string 121 to inside of canister 117.
In the
illustrated embodiment, rivet-style fastener 705 provides a limited pressure
seal
between the outside of tubing string 121 and the inside of canister 117.
[0031] Figure 8 depicts yet another embodiment of coupling 401. A canister
801 defines recesses 803 and 805 extending circumferentially about canister
801. A
tubing string 807 is permanently deformed at 809 and 811 into recesses 803 and
805 of
canister 801, respectively, to locate canister 801 with respect to tubing
string 807. It
should be noted that recesses 803 and 805 are merely exemplary of many various
profiles that may be defined by canister 801. A packing 813 is disposed
between
recesses 803 and 805 of canister 801, in the annulus between tubing string 807
and
canister 801. Packing 813 provides a pressure seal between the outside of
tubing
string 807 and the inside of canister 801. The material of packing 813 is
implementation
specific but may comprise a "swellable" packing material or an "injectable"
packing
material. A port 815 extends through tubing string 807, packing 813, and
canister 801
for communication of reservoir fluids from outside of tubing string 807 to the
inside of
canister 801.
[0032] Figures 9 and 10 depict stylized, schematic views, corresponding to
the view of Figure 4, of two particular embodiments of canister 117. It should
be noted
that the embodiments of Figures 9 and 10 may be applied to other canisters of
downhole array 111, such as canisters 113, 115, 119, and 801. In the
embodiment of
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Figure 9, canister 117 comprises a wet compartment 901 and a dry compartment
903.
Reservoir fluid is allowed to communicate into wet compartment 901 but is
inhibited
from communicating into dry compartment 903. Components, such as component
905,
are housed primarily in dry compartment 903, with only portions of the
components that
necessarily must contact the reservoir fluid extending through a bulkhead 907
into wet
compartment 901 to enhance the life of such components. Dry compartment 903
further provides protection to connections between conduit 123 and component
905
from reservoir fluids to enhance the life of such connections. Components,
such as
component 905, include, but are not limited to, sensors, such as temperature
sensors,
acoustic sensors, pressure sensors, and the like; and/or flow control devices,
such as
valves, regulators, nozzles, and the like. The flow control device or devices
may be
used, for example, in chemical injection, dewaterization, and gas lift
applications.
[0033] While some components, such as component 905 are sensitive to
reservoir fluids, other components, such as component 1001 of Figure 10, are
not so
sensitive. Accordingly, it may be advantageous in certain implementations for
such
components not to be protected from inadvertent contact with reservoir fluids.
Accordingly, as shown in Figure 10, canister 117 includes only wet compartment
901,
omitting dry compartment 903 (shown in Figure 9).
[0034] Still referring to Figure 10, in some embodiments, reservoir fluids are
inhibited from entering tubing string 121, except into wet compartment 901 or
other such
wet compartments, depending upon the implementation. Accordingly, an interior
volume of tubing string 121 serves as a dry compartment, corresponding to dry
compartment 903 (shown in Figure 9), and component 1001 is protected from
inadvertent contact with reservoir fluids. Thus, for the purposes of this
disclosure, the
term "dry compartment" means any confined volume of downhole array 111 that
lacks
fluid communication with reservoir fluid.
[0035] Figure 11 depicts a perspective view of a portion of downhole array
assembly 101. Canister 117 is representative of the canisters of downhole
array 111,
including canister 801 (shown in Figure 8). Downhole array 111 is installed
inside
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tubing string 121, for example, by pumping or pulling downhole array 111 into
position
within tubing string 121. The position of each of the canisters, such as
canister 117, is
determined using a device external to tubing string 121. In one embodiment, a
change
in density of downhole array assembly 101 is sensed, such as with an X-ray
machine, to
determine the location of canister 117 in tubing string 121. In other
embodiments,
canister 117 includes one or more tags 1101, such as radio frequency tags or
radioactive tags, which are sensed from outside tubing string 121 to determine
the
location of canister 117 within tubing string 121. Openings 1103 and 1105 are
generated in tubing string 121 and canister 117, respectively. Canister 117 is
then
coupled to tubing string 121 with coupling 401, such as the embodiments shown
in
Figures 5-8 and described herein. Figure 11 is exemplary of a sensor array
configuration of downhole array 111.
[0036] While Figures 9 and 10 depict canister 117 as including one
component 901, the scope of the present invention is not so limited. Rather,
one or
more of the canisters, such as canisters 115 and 117, may include a plurality
of
components including, but not limited to, sensors, such as temperature
sensors,
acoustic sensors, pressure sensors, and the like; and/or flow control devices,
such as
valves, regulators, nozzles, and the like. In Figure 12, canisters 115 and 117
each
include two such components 1201 and 1203. Note that components 1201 and 1203
may be the same type of component or different types of components.
[0037] While components 1201 and 1203 are depicted as being disposed
within canisters 115 and 117, the scope of the present invention is not so
limited.
Rather, as discussed herein regarding Figure 10, such components may be
disposed
external to a canister. Accordingly, Figure 13 depicts canisters 115 and 117
that omit
dry compartments, such that a plurality of components 1301 and 1303 extend
from
canisters 115 and 117 into the interior of tubing string 121.
[0038] While it is advantageous to employ downhole array 111 in tubing string
121 in some implementations, the scope of the present invention includes using
downhole array 111 without tubing string 121, as shown in Figure 14, for
example, in
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vertical wells. Wet compartment 901 defines a port 1401 to allow communication
of
reservoir fluid into wet compartment 901.
[0039] The particular embodiments disclosed above are illustrative only, as
the 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 embodiments disclosed above may be altered or modified and all such
variations are considered within the scope of the invention. Accordingly, the
protection
sought herein is as set forth in the claims below. Although the present
invention is
shown in a limited number of forms, it is not limited to just these forms, but
is amenable
to various changes and modifications.
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