Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: WATER SENSING DEVICES AND METHODS UTILIZING SAME
TO CONTROL FLOW OF SUBSURFACE FLUIDS
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates generally to systems and methods for selective
control of fluid flow into a wellbore.
2. Description of the Related Art
(0002) Hydrocarbons such as oil and gas are recovered from a
subterranean formation using a wellbore drilled into the formation. Such wells
are typically completed by placing a casing along the wellbore length and
perforating the casing adjacent each such production zone to extract the
formation fluids (such as hydrocarbons) into the wellbore. These production
zones are sometimes separated from each other by installing a packer
between the production zones. Fluid from each production zone entering the
wellbore Is drawn Into a tubing that runs to the surface. It is desirable to
have
substantially even drainage along the production zone. Uneven drainage
may result In undesirable conditions such as an invasive gas cone or water
cone. In the instance of an oil-producing well, for example, a gas cone may
cause an inflow.of gas into the wellbore that could significantly reduce oil
production- In like fashion, a water cone may cause an inflow of water into
the oil production flow that reduces the amount and quality of the produced
oil. Accordingly, it is desired to provide even drainage across a production
zone and / or the ability to selectively close off or reduce inflow within
production zones experiencing an undesirable influx of water and/or gas.
[0003] The present disclosure addresses these and other needs of the prior
art.
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SUMMARY OF THE DISCLOSURE
(00041 In aspects, the present disclosure provides an apparatus for
controlling fluid flow into a weilbore tubular. In one embodiment, the
apparatus includes a reactive element configured to react when exposed to a
fluid and a flow control device configured to control a flow of the fluid. The
flow control device may be actuated by a reaction of the reactive element to
the fluid, which may be water, a hydrocarbon, an engineered fluid, and 1 or a
naturally occurring fluid.
10005] In embodiments, the reactive element reacts by exhibiting a change
in a mechanical material property, a modulus, a storage modulus, a shear
strength, a glass transition temperature, ductility, hardness and / or
density.
In embodiments, the reaction of the reactive element may a deformation, a
bending, an expansion, contraction, and / or a twisting. In aspects, the
reactive element may be configured to have a chemical reaction to the fluid,
and / or a molecular reaction to the fluid. In aspects, the reaction of the
reactive element is reversible. In some embodiments, the reactive element
may be a shape memory polymer.
10006] In embodiments, the flow control device maybe a valve, an orifice,
and / or a tortuous path. Depending on the configuration of the flow control
device, the flow control device may be actuated by a compression applied by
the reactive element, and / or a tension applied by the reactive element. In
some arrangements, the flow control device includes an actuating element
operably coupled to the reactive element. The reaction of the reactive
element to a given fluid, such as water, releases the actuating element to
actuate the flow control device.
10007] In aspects, the present disclosure provides a method for producing
fluid from a subterranean formation. The method may include positioning a
reactive element downhole in a wellbore, and actuating a flow control device
in response to a reaction of the reactive element to a given fluid. The fluid
may be water, a hydrocarbon, an engineered fluid, and / or a naturally
occurring fluid. In some embodiments, the reactive element may be a shape
memory polymer.
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[0008) In aspects, the present disclosure provides a system for controlling
flow of one or more fluids into a welibore intersecting a subterranean
formation. The system may include a wellbore tubular conveying the one or
more fluids to a surface location, and a plurality of flow control devices
distributed along a section of the wellbore tubular. Each flow control device
may include a reactive element configured to react when exposed to a fluid.
Each of the flow control device may be actuated by a reaction of the reactive
element to the fluid to control a flow of the fluid into the wellbore tubular.
In
some embodiments, the reactive element may be a shape memory polymer.
[0009] It should be understood that examples of the more important
features of the disclosure have been summarized rather broadly in order that
detailed description thereof that follows may be better understood,. and in
order that the contributions to the art may be appreciated. There are, of
course, additional features of the disclosure that will be described
hereinafter
and which will form the subject of the claims appended hereto.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The advantages and further aspects of the disclosure will be readily
appreciated by those of ordinary skill in the art as the same becomes better
understood by reference to the following detailed description when
considered in conjunction with the accompanying drawings in which like
reference characters designate like or similar elements throughout the
several figures of the drawing and wherein:
Fig. 1 is a schematic elevation view of an exemplary multi-zonal
wellbore and production assembly which. Incorporates an inflow control
system in accordance with one embodiment of the present disclosure;
Fig. 2 is a schematic elevation view of an exemplary open hole
production assembly which Incorporates an inflow control system in
accordance with one embodiment of the present disclosure;
Fig. 3 is a schematic cross-sectional view of an exemplary production
control device made in accordance with one embodiment of the present
disclosure;
Fig. 4 is a schematic view of a flow control device made in accordance
with one embodiment of the present disclosure;
Fig. 5 is a schematic view of another flow control device made in
accordance with one embodiment of the present disclosure; and
Fig. 6 is a schematic view of still another flow control device made in
accordance with one embodiment of the present disclosure.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The present disclosure relates to devices and methods for
controlling production of a hydrocarbon producing well. The present
disclosure is susceptible to embodiments of different forms. There are shown
in the drawings, and herein will be described in detail, specific embodiments
of the present disclosure with the understanding that the present disclosure
is
to be considered an exemplification of the principles of the disclosure, and
is
not intended to limit the disclosure to that illustrated and described herein*
Further, while embodiments may be described as having one or more
features or a combination of two or more features, such a feature or a
combination of features should not be construed as essential unless
expressly stated as essential.
[0012] Referring initially to Fig. 1, there Is shown an exemplary wellbore 10
that has been drilled through the earth 12 and into a pair of formations 14,16
from which it Is desired to produce hydrocarbons. The wellbore 10 is cased
by metal casing, as is known in the art, and a number of perforations 18
penetrate and extend into the formations 14,16 so that production fluids may
flow from the formations 14, 16 Into the wellbore 10. The wellbore 10 has a
deviated, or substantially horizontal leg 19. The wellbore 10 has a late-stage
production assembly, generally indicated at 20, disposed therein by a
wellbore tubularor tubing string 22 that extends downwardly from a wellhead
24 at the surface 26 of the wellbore 10. The production assembly 20 defines
an internal axial flowbore 28 along its length. An annulus 30 is defined
between the production assembly 20 and the wellbore casing. The
production assembly 20 has a deviated, generally horizontal portion 32 that
extends along the deviated leg 19 of the wellbore 10. Production devices 34
are positioned at selected points along the production assembly 20.
Optionally, each production device 34 is isolated within the wellbore 10 by a
pair of packer devices 36. Although only two production devices 34 are
shown In Fig. 1, there may, in fact, be a large number of such production
devices arranged in serial fashion along the horizontal portion 32.
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O(0 131 Each production device 34 features a production control device 38'
that is used to govern one or more aspects of a flow of one or more fluids
into the production assembly 20. As used herein, the term "fluid" or "fluids"
includes liquids, gases, hydrocarbons, multi-phase fluids, mixtures of two of
more fluids, water, brine, engineered fluids such as drilling mud, fluids
injected from the surface such as water, and naturally occurring fluids such
as oil and gas. Additionally, references to water should be construed to also
include water-based fluids; e.g., brine or salt water. In accordance with
embodiments of the present disclosure, the production control device 38 may
have a number of alternative constructions that ensure selective operation
and controlled fluid flow therethrough.
[0014] Fig. 2 illustrates an exemplary open hole wellbore arrangement 11
wherein the production devices of the present disclosure may be used.
Construction and operation of the open hole wellbore 11 is similar In most
respects to the wellbore 10 described previously. However, the wellbore
arrangement 11 has an uncased borehole that is directly open to the
formations 14, 16. Production fluids, therefore, flow directly from the
formations 14, 16, and into the annulus 30 that is defined between the
production assembly 21 and the wall of the wellbore 11. There are no
perforations, and open hole packers 36 may be used to isolate the production
control devices 38. The nature of the production control device is such that
the fluid flow is directed from the formation 16 directly to the nearest
production device 34, hence resulting in a balanced flow. In some instances,
packers maybe omitted from the open hole completion.
[0015] Referring now to Fig. 3, there is shown one embodiment of a
production control device 100 forcontrolling the flow of fluids from a
reservoir
into a production string. This flow control can be a function of one or more
characteristics or parameters of the formation fluid, including water content,
fluid velocity, gas content, etc. Furthermore, the control devices 100 can be
distributed along a section of a production well to provide fluid control at
multiple locations. This can be advantageous, for example, to equalize
production flow of oil in situations wherein a greater flow rate is expected
at a
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"heel" of a horizontal well than at the "toe" of the horizontal well. By
appropriately configuring the production control devices 100, such as by
pressure equalization or by restricting inflow of gas orwater, a well owner
can
Increase the likelihood that an oil bearing reservoir will drain efficiently.
Exemplary production control devices are discussed herein below.
[0016] In one embodiment, the production control device 100 includes a
particulate control device 110 for reducing the amount and size of
particulates entrained in the fluids, an in-flow control device 120 that
controls
overall drainage rate from the formation, and a flow control device 130 that
controls in-flow area based upon the composition of a'flowing fluid. The
particulate control device 110 can include known devices such as sand
screens and associated gravel packs and the in-flow control device 120 can
utilize devices employing tortuous fluid paths designed to control inflow rate
by created pressure drops.
[0017] An exemplary flow control device 130 may be configured to control
fluid flow into a flow bore 102 based upon one or more characteristics (e.g.,
water content) of the in-flowing fluid. In embodiments, the flow control
device
130 is actuated by a reactive element 132 that. reacts with a specified fluid
in
the vicinity of the flow control device 130. By react or reaction, it is meant
that the reactive element 132 undergoes a change in one or more
characteristics or properties upon exposure to the specified fluid. The
characteristic or property may include, but is not limited to, a mechanical
property, an electrical property, and a material composition. Moreover, the
change may be reversible in some arrangements. That is, the reactive
element 132 may revert to an original condition once the specified fluid has
dissipated or is no longer present, Also, the reactive element 132 may revert
to an original condition upon exposure to another specified fluid.
Illustrative
reactive elements are described below.
[0018] Referring now to Figs. 4 and 5, there are shown embodiments of
flow control devices 200 and 240 that are actuated using reactive elements
202 and 242, respectively. In one Illustrative arrangement, the reactive
elements 202 and 242 incorporate a shaped memory polymer (SMP)
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material. An SMP material may be configured such that when a threshold
value for an activation parameter is exceeded. the SMP material undergoes a
transformation that manifests as a change in a material property. Illustrative
activation parameters include chemistry and heat. In one arrangement, a
water-activated SMP may use a glass transition temperature, or Tg, as a
threshold value for an activation parameter based on heat. The material
property affected may be storage modulus. In an exemplary configuration,
exposing a water-activated SMP material to water causes a transformation in
the SMP that manifests as a change in storage modulus. Thus, for instance.
prior to exposure to water, the SMP material may have a first Tg and after
exposure to water may have a lower second Tg. If a surrounding
temperature is between the first Tg and the second Tg, then exposing a
water-activated SMP material to water causes a shift between a relatively
stiff
condition to a relatively flexible condition.
[0019] Referring now to Fig. 4, the flow control device 200 utilizes a
reactive element:202 that may be operably coupled to a flow restriction
element 204 that is configured to partially or completely restrict flow
through
an orifice 206. The orifice 206, when open, may provide fluid communication
between the formation and the flow bore 102 (Fig. 3). The reactive element
202 is formed of a water-activated SMP material that has a Tg greater than
the ambient downhole temperature encountered by the flow control device
200 when the reactive element 202 is not exposed to water. For clarity, the
condition wherein the reactive element 202 is not exposed to a fluid that
induces a transformation will be referred to as a "null" activation. When
exposed to water, the water-activated SMP material has a Tg lower than the
ambient downhole temperature encountered by the flow control device 200.
In one arrangement, a lever 208 having a fulcrum at a connection point 210
connects the reactive element 202 to the flow restriction element 204. The
reactive element 202 may be formed as a band that engages one end of the
lever 208 that generates a force that counteracts the force urging the flow
restriction element 204 into a sealing engagement with the orifice 206. In
this
case, the force is gravity, but in other cases, a biasing member, hydraulic
pressure, etc., may urge the flow restriction element 204 toward the orifice
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206.
[0020] During the "null" activation, the reactive element 202 is sized to
orient the lever 208 such that the flow restriction element 204 is not engaged
with or seated on the orifice 206. Because the reactive element 202 Is
relatively stiff in the "nuIP activation, the lever208 and flow restriction
element
204 are generally static and remain in this position. A counter weight lobe
212 may also be positioned on the lever 208 to assist the reactive element
202 In applying the necessary force on the lever 208 to keep the flow
restriction element 204 unseated. When a sufficient amount of water
surrounds the reactive element 202, the reactive element 202 undergoes a
transformation that causes a drop In the value of Tg. Because the new Tg Is
below the ambient downhote temperature, the reactive element 202 becomes
flexible and loses Its capacity to apply a counter force on the lever 208. As
the weight of the flow restriction element 204 overcomes the force applied by
the reactive element 202, the flow restriction element 204 rotates into a
seating engagement with the orifice 206. Thus, the flow control device 200 is
actuated by the reaction of the reactive element 202 when exposed to water.
This reaction may be characterized as a change in material property in one
aspect, a change in shape in another aspect or a change in Tg in still another
aspect.
10021] If water no longer surrounds the reactive element 202, the value of
Tg returns to that for "null' activation. Thus, the reactive element 202
reverts
to its shape and / or size during "null" activation, which causes the flow
restriction element 202 to rotate out of engagement with the orifice 206.
Thus, the reaction of the reactive element 204 may be considered reversible.
[0022] In some embodiments, the F1g. 4 flow control device 200 may be
oriented in the wellbore such that gravity can pull the flow restriction
element
204 downward Into engagement with the orifice 206. In other embodiments,
the flow control device 200 may be rotatably mounted on a wetlbore tubular
22 (Fig. 1) and include a counter weight (not shown). Thus, upon being
positioned in the welibore, the counter weight causes the flow restriction
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element 204 to rotate into a wellbore highside position, which thus allows
gravity to act on the flow restriction element 204 in a manner previously
described.
f0023] Referring now to Fig. 5, the flow control device 240 utilizes the
reactive element 242 in an electrical circuit 244 that can move or displace a
flow restriction element 246 that partially or completely restricts flow
through
an orifice 248. The orifice 248, when open, may provide fluid communication
between the formation and the flow bore 102 (Fig. 3). The reactive element
242 is formed of a water-activated SMP material and is configured in the
same manner as described with respect to Fig. 4. In one arrangement, the
flow restriction element 248 Is coupled at a pivoting element 250 in a manner
that allows rotation between an open and closed position. The flow
restriction element 246 may be formed of a non-metallic material that
includes a magnetic element 252 that co-acts with the electrical circuit 244.
In an illustrative configuration, the electrical circuit 248 generates a
magnetic
field that attracts the magnetic element 252. The force applied by the
generated magnetic field pulls or rotates the flow restriction element 246 out
of engagement with the orifice 248. The electrical circuit 244 may be
energized using a surface power source that supplies power using a suitable
conductor and / or a downhole power source. Exemplary downhole power
sources Include power generators and batteries.
[0024] The electrical circuit 244 Includes a switch 254 that selectively
energizes an electromagnetic circuit 256. In some embodiments, the switch
254 may be a switch that is activated using an applied magnetic field, such
as a Reed switch. For example, the switch 254 may be moved between an
energized and non-energized position by a magnetic trigger 258. The
magnetic trigger 258 Includes a magnetic element 260 that may slide or shift
between two positions. Ina first position, the magnetic field generated by the
magnetic element 260 is distant from and does not affect the switch 254. In
a second position, the magnetic field generated by the magnetic element 260
is proximate to and does affect the switch 254. The switch 254 may be
configured to energize the electromagnetic circuit 256when the magnetic
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trigger258 is in the first position and de-energize the electromagnetic
circuit
256when the magnetic trigger 258 is in the second position. It should be
understood that, in addition to magnetic fields, the switch 254 may also be
activated by mechanical co-action, an electrical signal, a hydraulic or
pneumatic arrangement, a chemical or additive, or other suitable activation
systems.
[0025] Movement of the magnetic trigger 258 between the first position and
the second position is controlled by the reactive element 242 and a biasing
element 262. In the "null" activation, the reactive element 242 has a size and
stiffness than maintains the biasing element 262 in a compressed state and
the magnetic trigger 258 In the first position. When a sufficient amount of
water surrounds the reactive element 242, the reactive element 242 loses its
capacity to resist the biasing force applied by the biasing element 262. As
the biasing element 262 overcomes the resistive force of the reactive
element 242, the biasing element 262 slides the magnetic trigger 260 into the
second position. When magnetic elements 262 of the magnetic trigger 260
are sufficiently close to the switch 254, the switch 254 opens or breaks the
electromagnetic circuit 256 and thereby de-activates the magnetic field
generated by the electromagnetic circuit 256. Thereafter, gravity or some
other force urges the flow restriction element 246 to rotate Into engagement
with the orifice 248.
[0026] If water no longer surrounds the reactive element 242, the value of
Tg returns to that for "null activation. Thus, the reactive element 242
reverts
to shape and / or size during "nulr activation, which compresses the spring
262 and causes the magnetic trigger 260 to return to the first position.
Because the magnetic elements 260 no longer affect the switch 254, the
switch 254 re-energizes the electromagnetic circuit 244 and the generated
magnetic field causes the flow restriction element 244 to rotate out of
engagement with the orifice 248. Thus, again, the reaction of the reactive
element 242 may be considered reversible.
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10027] In some embodiments, the Fig. 5 flow control device 240 may be
positioned in the welibore such that gravity can pull the flow restriction
element 246 downward into engagement with the orifice 248. In other
embodiments, the flow control device 200 may be rotatabty mounted on a
weilbore tubular 22 (Fig. 1) and include a counter weight (not shown) in a
manner previously described in connection with Fig. 4.
[0028] Referring now to Fig. 6, there Is shown a flow control device 280
that utilizes a reactive element 282 that selectively blocks flow across an
orifice 284. The reactive element 282 may be formed of a water-activated
SMP material and utilized as an object commonly referred to as a "dart" that
maybe pumped down from the surface. The reactive element 282 may have
a "null" activation during the pump down in which the reactive element 282
has a shape and / or dimensions that allow the element 282 to enter the
orifice 284. Thereafter, exposure to water causes the element 282 to expand
and become secured within the orifice 284 and thereby partially or fully
occlude the orifice 284. In other embodiments, the reactive element 282 may
be positioned in the orifice 284 during initial installation and be formed of
an
SMP material that is oil-activated. Exposure to oil, or some other
hydrocarbon, may cause the reactive element 282 to transform from one size
to a smaller size. Thus, when oil surrounds the orifices 284, the reactive
element 282 reduces in size and falls out of the orifice 284. In still other
embodiments, the reactive element 282 may be positioned on or in the orifice
284 to selectively control flow through the orifice 284 based on the nature of
the surrounding fluid.
[0029] It should be understood that the above arrangements are merely
illustrative of flow devices according to the present disclosure. Forexample,
in some variants, a reactive element may be formed to have a non-reversible
reaction with a fluid. For instance, the reactive element may use a material
that reacts to a specified fluid by disintegrating. Exemplary types of
disintegration include, but are not limited to, oxidizing, dissolving,
melting,
and fracturing. Referring to Fig. 5, the reactive element 242 may be formed
of a material, such as aluminum, that oxidizes, or corrodes, when exposed to
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water. Thus, once water has sufficiently corroded an aluminum-based
reactive element 242, the biasing element 262 will shift the magnetic trigger
258 to the second position.
100301 In other variants, a reactive element maybe configured to react with
fluids other than water. For example, a reactive element may be configured
to utilize an oil-activated SMP material. Referring now to Fig. 4, an oil-
activated reactive element 202 may be configured to have a shape or
dimension that applies the counter force to maintain the flow restriction
element 204 in an open position as long as oil is present. If water displaces
the oil, then the oil-activated reactive element 202 reverts to a shape or
dimension associated with the "nuir activation and the flow restriction
element 204 moves to a closed position. In still other embodiments, the
reactive element 202 may be configured to react with an engineered fluid,
such as drilling mud, or fluids introduced from the surface such as brine. It
should also be understood that SMP materials are merely illustrative of the
type of materials that may be used for the reactive element. Any material
that undergoes a transformation in a property, dimension, shape, size, a
response to stimulus, etc. may be used for the reactive element.
[0031] In still other variants, an SMP material may be configured to use
activation thresholds based on parameters other than temperature, such as
pressure ordownhole compositions. Moreover, the activation parameter may
also be varied to provide an additional layer of control over the flow control
devices. For instance, the threshold value may be selected such that human
intervention may be used to complete an actuation of the flow control device.
In one scenario, the "null" activation Tg and the transformed value for Tg
may both be selected to be higher than the ambient wellbore temperature.
Thus, a second step of raising the ambient wellbore temperature may be
used to complete the actuation process for the flow control device.
[0032] Instill other variants, forces other than gravity may be used to move
flow restriction elements between an open position and a closed position.
For example, biasing members, such as springs, may be used to apply a
force that either keeps a flow restriction element in an open or closed
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position. The reactive element may be configured to counteract or restrain
the force applied by such a biasing element. Additionally, while Figs. I and 2
show production wells wherein fluid flows from a formation into a weilbore
tubular, embodiments of the present disclosure may be utilized in connection
with activities wherein fluid flows out of the wellbore tubular. For instance,
injection wells may be used to assist in drainage of a production well. In a
common use, water is Injected into an offset well to increase production from
a main well. Embodiments of the present disclosure may be used in those
and other situations to control fluid flow out of a weilbore tubular.
[0033] It should be understood that Figs. I and 2 are intended to be merely
illustrative of the production systems in which the teachings of the present
disclosure may be applied. For example, in certain production systems, the
wellbores 10, 11 may utilize only a casing or liner to convey production
fluids
to the surface. The teachings of the present disclosure may be applied to
control flow to those and other wellbore tubulars.
[0034] For the sake of clarity and brevity, descriptions of most threaded
connections between tubular elements, elastomeric seals, such as o-rings,
and other well-understood techniques are omitted in the above description.
The foregoing description is directed to particular embodiments of the
present disclosure for the purpose of illustration and explanation. It will be
apparent, however, to one skilled In the art that many modifications and
changes to the embodiment set forth above are possible without departing
from the scope of the disclosure.
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