GB2602815A

GB2602815A - Inflow control device

Info

Publication number: GB2602815A
Application number: GB2100514.5A
Authority: GB
Inventors: Wasa Tverlid Steinar; Ibragimova Zalpato; Torsvik Jone; Vabo Marta
Original assignee: Equinor Energy AS
Current assignee: Equinor Energy AS
Priority date: 2021-01-15
Filing date: 2021-01-15
Publication date: 2022-07-20
Also published as: GB202100514D0

Abstract

An apparatus 210 for controlling the flow of fluids into a tubular located in a well comprises a fluid inlet 214 configured to be in fluid communication with a volume outside of the tubular; a fluid outlet 216 configured to be in fluid communication with an internal volume 224 of the tubular. A valve assembly 220 is located between the fluid inlet and the fluid outlet; and a reversibly water-swellable material 212 configured to be in mechanical contact with the valve assembly, wherein the apparatus is configured to provide contact between the fluids and the water-swellable material, wherein the valve assembly is configured to, responsive to a swelling of the water-swellable material produced by an increase in the water content in the fluids, restrict the flow of the fluids into the tubular.

Description

INFLOW CONTROL DEVICE

Technical Field

The present invention relates to controlling the flow of fluids from a subsurface formation of the Earth into a tubular located in a well extending through the formation, in particular based on the water content in the fluids.

Backeifound A known device for recovering hydrocarbons from a horizontal or vertical well comprises a perforated pipe with, for example, a sand-control filter around the pipe. The well is typically an open-hole well, and the well and pipe may extend through multiple reservoir zones with different properties.

The fluids in a reservoir may include a layer of oil, and a layer of water beneath the oil. When the rate of production of the reservoir fluids into the pipe increases beyond a certain threshold, the oil/water interface may be drawn up in a cone or bell shape centred on the point at which the fluids are entering the pipe, resulting in 'water coning'. As the degree of water coning increases, increasing amounts of water will be recovered along with the hydrocarbons. It is typically labour-and cost-intensive to separate the unwanted water out from the fluids to provide hydrocarbons that are commercially viable.

Further, where a reservoir zone of a formation is substantially depleted of hydrocarbons and is producing water, this unwanted water will enter the well and reduce the proportion of valuable hydrocarbons in the total produced fluids.

Summary

It is an object of the present invention to overcome or at least mitigate the problems identified above.

In accordance with a first aspect of the present invention there is provided an apparatus for controlling the flow of fluids into a tubular located in a well extending through a subsurface formation of the Earth, the apparatus comprising: a fluid inlet configured to be in fluid communication with a volume outside of the tubular; a fluid outlet configured to be in fluid communication with an internal volume of the tubular; a valve assembly located between the fluid inlet and the fluid outlet; and a reversibly water-swellable material configured to be in mechanical contact with the valve assembly, wherein the apparatus is configured to provide contact between the fluids and the water-swellable material, wherein the valve assembly is configured to, responsive to a swelling of the water-swellable material produced by an increase in the water content in the fluids, restrict the flow of the fluids into the tubular.

The valve assembly may comprise an autonomous butterfly valve.

The autonomous butterfly valve may be configured to be actuated by a change in the flow of fluids incident on the autonomous butterfly valve.

The autonomous butterfly valve may comprise a disc and a shaft about which the disc is configured to rotate, and the valve assembly may further comprise: a chamber that contains the autonomous butterfly valve and is configured to be substantially sealed by the disc of the valve; a dividing wall that separates the internal volume of the chamber upstream of the autonomous butterfly valve into a first section and a second section, wherein the shaft of the butterfly valve extends across the chamber in the plane of the dividing wall; at least one abutment shoulder configured to prevent movement of the disc past a position in which the chamber is substantially sealed by the disc; and an inlet conduit extending between the fluid inlet and the chamber, wherein a proximate end of the inlet conduit adjacent to the chamber is configured to be movable between a first position in which at least the majority of the fluids are directed into the first section, and a second position in which at least the majority of the fluids are directed into the second section, wherein the water-swellable material is configured to be in mechanical contact with the inlet conduit, such that swelling of the water-swellable material causes the proximate end of the inlet conduit to be moved towards the second position.

The fluids may comprise hydrocarbons from the formation.

The apparatus may be configured to stop flow of the fluids into the tubular.

The water-swellable material may be a polymer comprising hydrophilic and hydrophobic polymer components.

The apparatus may be configured to be included in, or located adjacent to, a tubular wall.

The apparatus may further include a screen portion that enables contact between the water-swellable material and the fluids.

In accordance with a second aspect of the present invention there is provided a tubular comprising the apparatus of the first aspect.

In accordance with a third aspect of the present invention there is provided a method for controlling the flow of fluids into a tubular located in a well extending through a subsurface formation of the Earth, comprising: providing a tubular comprising the apparatus of the first aspect in a well extending through a subsurface formation of the Earth, and using the apparatus to, responsive to the swelling of the water-swellable material produced by an increase in the water content in fluids produced from the formation, restrict the flow of the fluids into the tubular.

The tubular may be located in an open-hole reservoir zone of the well.

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Brief Description of Drawings

Figure 1A shows a side-on cross-sectional view of a tubular including an apparatus for controlling the flow of fluids into the tubular.

Figure 1B shows an external view of a tubular including an apparatus for controlling the flow of fluids into the tubular.

Figure 2 shows a side-on cross-sectional view of an apparatus for controlling the flow of fluids into the tubular, with end-on cross-sectional views from different points along the apparatus.

Figure 3 shows a configuration of the apparatus in the presence of oil with moderate water content.

Figure 4 shows a configuration of the apparatus in the presence of oil having a high water content.

Figure 5 shows a configuration of the apparatus in the presence of oil having a low water content.

Figure 6 shows a high-level flow diagram.

Detailed Description

The invention provides an apparatus for controlling the flow of fluids into a tubular located in a well extending through a subsurface formation of the Earth. The fluids are e.g. fluids produced from the formation, where the fluids comprise hydrocarbons such as oil and/or gas, and water. The apparatus comprises a fluid inlet configured to be in fluid communication with a volume outside of the tubular; a fluid outlet configured to be in fluid communication with an internal volume of the tubular; a valve assembly located between the fluid inlet and the fluid outlet; and a reversibly water-swellable material coupled to the valve assembly. The apparatus is configured to provide contact between the fluids, e.g. fluids outside the tubular, and the water-swellable material. The valve assembly is configured to, responsive to a swelling of the water-swellable material produced by an increase in the water content in the fluids, restrict the flow of the fluids into the tubular.

The invention therefore provides a new type of autonomous inflow control device (AICD) that is triggered and actuated based on the presence and content of water in fluids from a formation. This is in contrast with existing AlCDs, in which the inflow is controlled based on the density and/or viscosity of the fluids. Such existing AlCDs may not be able to control the flow as intended where the difference in density/viscosity for two fluid components is not sufficiently large, e.g. for light oils and water. The present invention, in contrast, is able to control the inflow based on water content, regardless of the difference in density/viscosity.

The present invention may therefore be useful in controlling or preventing water coning. Water coning occurs when the inflow rate increases beyond a certain threshold, depending at least on the thickness of the oil layer and the viscosity of the oil. When the water content in the fluids exceeds a certain threshold, due in this example to the occurrence of water coning, the apparatus of the invention will restrict the inflow of fluids into the tubular, thereby decreasing the inflow rate below the threshold at which water coning occurs. The present invention can therefore prevent, or at least mitigate the impact of, water coning. Where the tubular extends through multiple reservoir zones with different properties, the invention may enable the inflow from the different zones to be balanced to maximise hydrocarbon production.

The valve included in the valve assembly is e.g. a valve that uses energy from the fluid flow itself to change the valve state. This has the advantage that the apparatus of the invention does not require any external power source (i.e. no electrical power, mud turbine, or any other external power source is required to actuate the valve).

Figure 1A shows an apparatus 110 in accordance with the invention, installed in a tubular 180. Figure 1A shows a side-on cross-sectional view of the tubular and apparatus. In the embodiment shown in Figure 1A, the tubular is part of a screen assembly coupled to production tubing, where the production tubing is located in a well extending through a subsurface formation 150 of the Earth. In another embodiment, the tubular is a section of production tubing, casing, pipe or any other suitable tubular. The tubular 180 is configured to convey fluids, e.g. hydrocarbons, as illustrated by arrows 165,175. It is envisaged that the portion of the well in which the tubular 180 is located is an open-hole portion of the well in a reservoir zone, or production zone, of the formation. That is, the formation is located outside of the tubular, with no other larger-diameter pipe between the tubular and the formation.

The apparatus 110 is located within a wall 182 of the tubular 180. In an alternative embodiment, the apparatus is located partially within the wall, or adjacent to the wall. The apparatus is configured to control the flow of fluids from the formation 150 into the tubular 180. The apparatus 110 includes a fluid inlet 114 that is in fluid communication with the volume of the well outside of the tubular 180, and a fluid outlet 116 that is in fluid communication with the internal volume of the tubular. The apparatus is configured such that fluids from the formation enter the apparatus through the fluid inlet 114, pass through the apparatus (or do not pass through, depending on the water content of the fluids) and enter the internal volume of the tubular via the fluid outlet 116.

A valve assembly (not shown here, but will be described below with reference to other Figures) is located between the fluid inlet and the fluid outlet. A water-swellable material 112, in particular a reversibly water-swellable material, is coupled to the valve assembly. The apparatus is configured to provide contact between the fluids and the waterswellable material. In the embodiment shown in Figure 1A, this is achieved by exposing the water-swellable material 112 to the fluids outside of the tubular, using a screen portion of the apparatus wall or tubular wall(not shown here but described below with reference to other Figures) behind which the water-swellable material is located. Of course, any other suitable configuration may be used to expose the water-swellable material to the fluids. The valve assembly is configured to, responsive to a swelling of the water-swellable material produced by an increase in the water content in the fluids, restrict the flow of the fluids into the tubular. In particular, in a situation where the water content of the fluids increases beyond a threshold concentration, the water-swellable material will swell to such a degree that the valve assembly completely restricts flow of the fluids into the tubular. Responsive to a decrease in the water content, the water-swellable material will shrink, and the valve assembly will again permit flow of the fluids into the tubular. It is envisaged that the apparatus, or multiple such apparatuses, will provide the flow path, in particular the only flow path, for fluids from the formation into the tubular.

The reversibly water-swellable material 112 is e.g. a polymer. In particular, in the embodiment of Figure 1A, the reversibly water-swellable material is a switchable polymer comprising hydrophobic and hydrophilic polymer components. The switchable polymer is in particular a polymer that is able to swell and at the same time initiate hydrophobic interactions. That is, the polymer groups that cannot receive water will accumulate /join and restrict further adoption of water molecules in the groups that can take up water. The power of this behaviour depends on the concentration of water. With a low concentration of water there is low adoption of water and a strong gel structure. In contrast, with a high concentration of water there is a high adoption of water, and a weaker gel structure, which results in swelling. The ratio of hydrophobic to hydrophilic components in the switchable polymer is configured to provide a degree of swelling that is sufficient to cause the valve assembly to restrict the flow of the fluids into the tubular when the water content in the fluids exceeds a threshold value. The switchable polymer is preferably inert in pure oil. The hydrophilic polymer component comprises e.g. one or more of an acrylic acid-based polymer, an ester of alpha-methyl acrylic acid, an acryl-amid-based polymer, and a poly-ethylene glycol. These are polymers which include carboxyl groups that provide hydrophilic properties. The hydrophobic polymer component comprises e.g. one or more of polystyrene, poly-methyl methacrylate, and poly-2-hydroxyethyl methacrylate (which is hydrophilic but not water soluble and rather water -swellable).

The switchable polymer swells in the presence of water, in particular in the presence of oil containing water. The degree of swelling is dependent on the water content in the oil, i.e. when a greater proportion of the fluids is water, the switchable polymer swells more. In an embodiment, the time taken for the switchable polymer to change from its non-swelled state to a fully swelled state is between 10 and 72 hours, between 10 and 48 hours, between 10 and 24 hours, or between 10 and 15 hours. In an alternative embodiment, the time taken for the switchable polymer to change from its non-swelled state to a fully swelled state is e.g. between 30 minutes and 8 hours, between 30 minutes and 4 hours, or between 30 minutes and 2 hours. The swelling of the switchable polymer reverses, and preferably reverses completely, if access to water is removed, e.g. when the switchable polymer is exposed again to pure oil, or reduces if the water content in the fluids is reduced. In an embodiment, the time taken for the switchable polymer to change from its fully swelled state to its non-swelled state is between 10 and 72 hours, between 10 and 48 hours, between 10 and 24 hours, or between 10 and 15 hours. In an alternative embodiment, the time taken for the switchable polymer to change from its fully swelled state to its non-swelled state is e.g. between 30 minutes and 8 hours, between 30 minutes and 4 hours, or between 30 minutes and 2 hours. The switchable polymer therefore performs as a sensor for the presence of water in oil, by swelling when there is water and contracting when water is no longer present or is present in reduced quantity.

Figure 1B shows a 3D perspective view of the apparatus installed in a wall 182 of a tubular 180. The fluid inlet 114 is located at the top of the tubular. The above mentioned screen portion 188 of the apparatus wall or tubular wall provides the water-swellable material with access to the fluids outside of the tubular.

In the embodiment of Figure 1A and 1B, the well is a substantially horizontal well. The present invention can of course be applied in a well with any other orientation, e.g. a vertical well. Further, in the embodiment of Figure 1A and 1B the tubular is orientated so that the apparatus 110 is located in the top wall of the tubular, such that the fluid inlet 114 faces up. Of course, the tubular can have any other orientation, such that the fluid inlet faces in any other suitable direction. For example, in an alternative embodiment, the apparatus 110 is located in a bottom wall of the tubular and the fluid inlet faces down.

Figure 2 shows a side-on cross-sectional view of the apparatus of Figure 1A and 1B, with further detail of the valve assembly shown. Like features are indicated by reference numerals incremented by one hundred. The apparatus 210 includes the fluid inlet 214, fluid outlet 216, water-swellable material 212, screen portion 288, and a valve assembly located between the fluid inlet 214 and fluid outlet 216.

In the embodiment of Figure 2, the valve assembly includes an autonomous butterfly valve 220. In particular, the butterfly valve 220 is autonomous in the sense that it is configured to be actuated by a change in the flow of fluids incident on the valve, and therefore requires no outside power source (e.g. electrical power provided by a battery or power cable) to operate. The autonomous butterfly valve 220 comprises a disc and a shaft about which the disc is configured to rotate. The valve assembly further comprises a chamber 224 that contains the autonomous butterfly valve 220 and is configured to be substantially sealed by the disc of the valve. A dividing wall 222 separates the internal volume of the chamber 224 upstream of the autonomous butterfly valve 220 into a first section 224a and a second section 224b, and the shaft of the butterfly valve extends across the chamber in the plane of the dividing wall 222. In the embodiment of Figure 2, the first section is an upper section, and the second section is a lower section. At least one abutment shoulder 228 is configured to prevent movement of the disc past a position in which the chamber is substantially sealed by the disc. In the embodiment of Figure 2 there are two abutment shoulders coupled to an inside wall of the chamber.

An inlet conduit 218 extends between the fluid inlet 214 and the chamber 224. A proximate end of the inlet conduit 218 that is adjacent to the chamber 224 is configured to be movable between a first position in which at least the majority of the fluids are directed into the first section 224a, and a second position in which at least the majority of the fluids are directed into the second section 224b. In the embodiment of Figure 2 the inlet conduit has a ribbed portion that provides at least some flexibility in the ribbed portion, and thereby permits movement of the proximate end of the inlet conduit between the first position and the second position. Of course, any alternative way of enabling said movement is possible, e.g. using an inherently flexible material for the inlet conduit. The water-swellable material 212 is contained in the apparatus in a volume adjacent to at least a portion of the inlet conduit. Further, the water-swellable material is asymmetrically distributed around the at least a portion of the inlet conduit, and in particular is located on one side of the at least a portion of the inlet conduit.

When the water-swellable material swells or shrinks, this causes the proximate end of the inlet conduit to move. In particular, when the water-swellable material swells in the presence of water, the proximate end of the inlet conduit is moved toward the second position, and when the water-swellable material shrinks when the presence of water is removed or reduced the proximate end of the inlet conduit is moved toward the first position. A biasing element 217, e.g. a spring, is coupled to the inlet conduit and urges the proximate end of the inlet conduit toward the first position, in opposition to the forces imposed on the proximate end by swelling of the water-swellable material. In some embodiments the biasing element may not be required, if the water-swellable material is fixably attached to the at least a portion of the inlet conduit. A pressure-equalisation outlet 219 provides fluid communication between the volume adjacent to at least a portion of the inlet conduit (in which the water-swellable material 212 is contained) and the volume of the well outside of the tubular. This permits free movement of the inlet conduit within the volume adjacent to at least a portion of the inlet conduit, and prevents the hydraulic 'locking' that could occur in the absence of such a pressure-equalisation outlet.

When the proximate end of the inlet conduit is in the first position, at least the majority of the fluids, in some cases all of the fluids, are directed into the first section of the chamber. The fluid flow through the first section causes the butterfly valve to open. As the water content in the fluids increases and the water-swellable material swells, the proximate end is moved toward the second position. When the water content exceeds a threshold value and the proximate end reaches the second position, at least the majority of the fluids, and in some cases all of the fluids, are directed into the second section of the chamber, and this causes the butterfly valve to move towards the closed position, and thereby restrict the flow of the fluids.

The autonomous butterfly valve could also be referred to as a flip valve, in particular a double barrel valve with a connected flip block located in the two barrels. The 'signal' from the polymer directs flow from the inlet conduit through either one or the other barrel, which respectively closes or opens the flip block and therefore also the flow. The valve uses energy from the flow through it to close and open. The valve will autonomously close in presence of water and open again when the water disappears or reduces in content.

Figure 2 also shows end-on slice representations of the cross-section of the apparatus along lines A-A, B-B, C-C, D-D and E-E. The cross-section A-A shows the simple circular profile of the inlet conduit. The section B-B shows the water-swellable material 212, the inlet conduit 218, and the biasing element 217. The section C-C shows the first section 224a and second section 224b of the chamber 224 upstream of the autonomous butterfly valve 220. Section D-D shows a portion of the chamber 224 downstream of the valve 220 which is not separated into two sections. Profile E-E shows the simple circular profile of an outlet conduit.

Of course, any other suitable valve assembly may be used as an alternative to the configuration shown in Figure 2.

Figure 3 illustrates the apparatus in a situation in which the fluids 390 flowing through the apparatus include oil and some water. The flow of the fluids 390 through the apparatus is illustrated by arrow 395. In particular, the fluids are at a balance point (tipping point), and the water content is at a maximum acceptable limit. In this case, the water-swellable material 312 is swelled to some degree, i.e. the H20 molecule exchange at the interface between the fluids and the water-swellable material is balanced, and the proximate end of the inlet conduit 318 is substantially equidistant between the first position and the second position. The flow through the first 324a and second 324b sections of the chamber is therefore substantially equal, and the flow over each side of the butterfly valve 320 is the same. In this situation the valve is at a tipping point, i.e. the valve state is unstable and the butterfly valve 320 may be open, in which case the flow of the fluids into the tubular through the apparatus is permitted (as shown in Figure 3), or may be closed, or may change between these states. When the water content is below the maximum acceptable limit, the butterfly valve 320 will be open as shown in Figure 3.

Figure 4 illustrates the apparatus in a situation in which the fluids 490 flowing through the apparatus include oil and a large amount of water, in particular an amount of water that is larger than the threshold amount. The flow of the fluids 490 through the apparatus is illustrated by arrow 495. The increased water content in the fluids increases absorption of water into the water-swellable material 412 and causes it to swell. The increased swelling causes the proximate end of the inlet conduit 418 to move to the second position, in which at least the majority of the fluid flow is directed into the second section 424b of the chamber. This moves the butterfly valve towards the closed position and thereby restricts flow of the fluids into the tubular. In particular, the butterfly valve is closed and the fluid flow into the tubular is completely restricted. In an embodiment, the large amount of water is present due to water coning. In another embodiment, the large amount of water is present because the hydrocarbons in the relevant zone of the formation have been depleted and only water, or large amounts of water relative to the amount of other fluids, are being produced. In this case there may be no water coning.

Figure 5 illustrates the apparatus in a situation in which the fluids 590 flowing through the apparatus include oil and no water, or only traces of water. The flow of the fluids 590 through the apparatus is illustrated by arrow 595. In an embodiment, the reduced water content results from a reduction in water coning, responsive to the restriction of flow imposed in the configuration shown in Figure 4. In particular, without flow from the formation into the tubular, gravity drains water from the oil zone (that is, without the flow from the formation drawing the oil/water interface into the bell or cone shape indicative of water coning, the water/oil interface settles into a more 'flat' configuration further away from the well). The reduced/low water content in the fluids 590s causes a net rejection of water from the water-swellable material 512, which in turn leads to a reduction in the volume of the water-swellable material, i.e. shrinkage. This shrinkage causes the proximate end of the inlet conduit 518 to move to the first position, in which at least the majority of the flow is directed into the first section 524a of the chamber. This causes the butterfly valve 520 to open, permitting maximum flow of the fluids through the apparatus into the tubular.

It is noted that where the butterfly valve is closed due to the presence of a large amount of water, where the large amount of water is present because of the depletion of hydrocarbons and there is no coning (as set out above in relation to Figure 4), the water will not retract, the swellable material will not shrink, and the butterfly valve will stay closed. This will allow other hydrocarbon-producing parts of the well to continue producing while the section of the tubular including the apparatus remains closed to fluids from the formation, thereby restricting unwanted water production which otherwise would enter the well and reduce the proportion of valuable hydrocarbons in the total produced fluids.

Figure 6 shows a high-level flow diagram describing a method in accordance with the invention. In step S602, a tubular comprising an apparatus is provided in a well extending through a subsurface of the Earth, wherein the apparatus is for controlling the flow of fluids into the tubular, the apparatus comprising: a fluid inlet configured to be in fluid communication with a volume outside of the tubular; a fluid outlet configured to be in fluid communication with an internal volume of the tubular; a valve assembly located between the fluid inlet and the fluid outlet; and a reversibly water-swellable material configured to be in mechanical contact with the valve assembly, wherein the apparatus is configured to provide contact between the fluids and the water-swellable material, wherein the valve assembly is configured to, responsive to a swelling of the water-swellable material produced by an increase in the water content in the fluids, restrict the flow of the fluids into the tubular. In step S604, the apparatus is used to, responsive to the swelling of the water-swellable material produced by an increase in the water content in fluids produced from the formation, restrict the flow of the fluids into the tubular.

It will be appreciated by the person of skill in the art that various modifications may be made to the above described embodiments without departing from the scope of the present invention.

Claims

Claims 1. An apparatus for controlling the flow of fluids into a tubular located in a well extending through a subsurface formation of the Earth, the apparatus comprising: a fluid inlet configured to be in fluid communication with a volume outside of the tubular; a fluid outlet configured to be in fluid communication with an internal volume of the tubular; a valve assembly located between the fluid inlet and the fluid outlet; and a reversibly water-swellable material configured to be in mechanical contact with the valve assembly, wherein the apparatus is configured to provide contact between the fluids and the water-swellable material, wherein the valve assembly is configured to, responsive to a swelling of the water-swellable material produced by an increase in the water content in the fluids, restrict the flow of the fluids into the tubular.
2. The apparatus of claim 1, wherein the valve assembly comprises an autonomous butterfly valve.
3. The apparatus of claim 2, wherein the autonomous butterfly valve is configured to be actuated by a change in the flow of fluids incident on the autonomous butterfly valve.
4. The apparatus of claim 2 or 3, wherein the autonomous butterfly valve comprises a disc and a shaft about which the disc is configured to rotate, and the valve assembly further comprises: a chamber that contains the autonomous butterfly valve and is configured to be substantially sealed by the disc of the valve; a dividing wall that separates the internal volume of the chamber upstream of the autonomous butterfly valve into a first section and a second section, wherein the shaft of the butterfly valve extends across the chamber in the plane of the dividing wall; at least one abutment shoulder configured to prevent movement of the disc past a position in which the chamber is substantially sealed by the disc; and an inlet conduit extending between the fluid inlet and the chamber, wherein a proximate end of the inlet conduit adjacent to the chamber is configured to be movable between a first position in which at least the majority of the fluids are directed into the first section, and a second position in which at least the majority of the fluids are directed into the second section, wherein the water-swellable material is configured to be in mechanical contact with the inlet conduit, such that swelling of the water-swellable material causes the proximate end of the inlet conduit to be moved towards the second position.
5. The apparatus of any one of the preceding claims, wherein the fluids comprise hydrocarbons from the formation.
6. The apparatus of any one of the preceding claims, wherein the apparatus is configured to stop flow of the fluids into the tubular.
7. The apparatus of any one of the preceding claims, wherein the water-swellable material is a polymer comprising hydrophilic and hydrophobic polymer components.
8. The apparatus of any one of the preceding claims, configured to be included in, or located adjacent to, a tubular wall.
9. The apparatus of any one of the preceding claims, further including a screen portion that enables contact between the water-swellable material and the fluids.
10. A tubular comprising the apparatus of any one of claims 1 to 9.
11. A method for controlling the flow of fluids into a tubular located in a well extending through a subsurface formation of the Earth, comprising: providing a tubular comprising the apparatus of any one of claims 1 to 9 in a well extending through a subsurface formation of the Earth, and using the apparatus to, responsive to the swelling of the water-swellable material produced by an increase in the water content in fluids produced from the formation, restrict the flow of the fluids into the tubular.
12. The method of claim 11, wherein the tubular is located in an open-hole reservoir zone of the well.