AU2020227008A1

AU2020227008A1 - A Valve and a Fluid System

Info

Publication number: AU2020227008A1
Application number: AU2020227008A
Authority: AU
Inventors: David John Roberts
Original assignee: Project Eng Wa Pty Ltd
Current assignee: Project Engineering Wa Pty Ltd
Priority date: 2019-08-30
Filing date: 2020-08-31
Publication date: 2021-03-18
Also published as: AU2022291528A1

Abstract

The present invention a valve (19) adapted to inject fluid into, and abstract fluid from a reservoir (13). The valve comprises a housing (33) having a first end (23) adapted to be secured to a first pipe (21), and a second end (27) adapted to be in fluid communication with a pump (25). The valve also comprises a sleeve (35) slidingly retained in the housing. The sleeve is movable relative to the housing between a first position wherein the valve is in an injection mode for injecting fluid into the reservoir, and a second position wherein the valve is in an abstraction mode for abstracting fluid from the reservoir. The present invention also provides a fluid system incorporating the valve. 2/5 67 '53 3 _____ ____41 Figure 2

Description

2/5

67 '53

3

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Figure 2

A Valve and a Fluid System

TECHNICAL FIELD

[0001] The present invention generally relates to a valve for use in a borehole, and a fluid system incorporating such a valve.

[0002] In particular the invention relates to a valve which is used to control the flow of liquid being injected into and extracted from a subterranean reservoir.

BACKGROUND ART

[0003] Generally, borehole injection valves are used to control the amount of water being injected into a subterranean aquifer. The valve is typically located within the borehole at the lower end of a downpipe at an optimum level relative to the depth of the subterranean aquifer. The valve is usually operated from the surface using a powered hydraulic system. The hydraulic system is connected to the valve to control operation of the valve. In order to vary the flow rate of water being injected, and depending on the valve type, the hydraulic system may operate a piston within a cylinder of the valve, cause sliding movement of a sleeve mounted on the outer periphery of the valve housing, or cause the inflation/deflation of a flexible tube within the valve housing.

[0004] Some boreholes have a requirement where abstraction of water is required in addition to injection of water. This requires a submersible electrically driven pump to be fitted to a lower end of the injection valve and it is this form of valve. Such a valve is referred to as a combined injection valve.

[0005] Current valves of this type employ a hollow tube housing mounted on the lowest end of a borehole downpipe and have an electrically driven submersible pump mounted at the lower end of the housing. The submersible pump is fitted with a non-return valve to prevent water entering the pump during injection. The housing employs a sliding sleeve which is externally mounted and hydraulically operated. This sleeve progressively exposes or covers a number of openings provided in the valve housing wall, allowing the flow of water into the aquifer to be controlled when water is being injected therein. When the abstraction of water from the aquifer is required the sleeve is positioned to cover the openings and the submersible pump directs water through the valve and up the downpipe to the surface. With this valve, the sleeve is caused to slide by means of a separate powered hydraulic system located at ground level. This system uses oil as the operating medium and requires a power supply. As many boreholes/aquifers are in remote locations making maintenance of the powered hydraulic system very difficult. Also, environmental regulations prohibit contamination of any kind within pristine aquifers, thereby prohibiting the use of oil operated equipment. In addition, these systems require an electric cable that is supported by the borehole downpipe to supply power for the submersible pump. This cable passes over and adjacent to the sliding sleeve thereby presenting a potential for wearing/abrasion of the cable by the reciprocating action of the sleeve and can result in electrical failure.

[0006] Furthermore, boreholes commonly gather surface debris for a variety of reasons which can become wedged between the sliding sleeve and the borehole casing resulting in jamming of the sleeve, and malfunction of the valve.

[0007] The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

SUMMARY OF INVENTION

[0008] It is an object of this invention to provide a valve and a fluid system which ameliorates, mitigates or overcomes, at least one disadvantage of the prior art, or which will at least provide the public with a practical choice.

[0009] Throughout the specification the term 'reservoir' is used to describe a subterranean body of fluid, such as water.

[0010] Throughout the specification the term 'borehole' is used to describe any passageway, conduit, pipe, channel or similar pathway extending from a reservoir to an alternative location, such as a dam.

[0011] The present invention provides a valve adapted to inject fluid into, and abstract fluid from a reservoir, the valve comprises: a housing having a first end adapted to be secured to a first pipe, and a second end adapted to be in fluid communication with a pump; a sleeve slidingly retained in the housing, the sleeve being movable relative to the housing between a first position wherein the valve is in an injection mode for injecting fluid into the reservoir, and a second position wherein the valve is in an abstraction mode for abstracting fluid from the reservoir.

[0012] The housing and sleeve may co-operate to define a valve passage through the valve. The passage valve may extend from the first end to the second end.

[0013] The housing may have a channel therethrough, wherein the sleeve is slidingly retained in the channel.

[0014] Adjacent the second end of the valve, the housing may provide one or more outlets. The one or more outlets may be in fluid communication with the valve passage when the valve is in the injection mode. The outlets may not be in fluid communication with the valve passage when the valve is in the abstraction mode.

[0015] Preferably the valve provides at least one chamber. The volume of the at least one chamber may be adjusted to selectively move the sleeve relative to the housing.

[0016] The at least one chamber may be in the form of an annular ring.

[0017] The at least one chamber may be sealed from the valve passage.

[0018] The chamber may be formed between the sleeve and the housing.

[0019] In one aspect of the invention there are two annular rings in spaced apart relation.

[0020] In another aspect of the invention the housing may have an annular recess incorporated in an internal wall thereof. An outer portion of the sleeve may be adapted to be slidingly received in the annular recess. The outer portion may co-operate with the annular recess of the housing to define an uppermost position of the sleeve relative to the housing and a lowermost position of the sleeve relative to the housing. The outer portion of the sleeve may be in the form of a projection extending outwardly from an outer surface of the sleeve. The outer portion may be dimensioned to be wider than the internal diameter of the channel of the housing, and narrower than the internal diameter of the annular recess. The projection may be in the form of an annular ring. The annular ring may be formed in the outer surface of the housing. The length of the projection may be shorter than the length of the annular recess by an amount at least equal to the diameter of the outlets formed in the housing.

[0021] In yet another aspect of the invention, the sleeve provides one or more annular rings extending outwardly from the outer surface of the sleeve, the one or more annular rings forming one or more chambers with the continuous inner surface of the channel of the housing.

[0022] An upper portion of the chamber may be adapted to receive and discharge a working fluid therefrom. A lower portion of the chamber may be adapted to discharge and receive the working fluid therefrom.

[0023] Preferably the valve is a combined injection valve.

[0024] The present invention further provides a combined injection valve for injecting fluid into, and abstracting fluid from a reservoir, the valve comprises:

a hollow housing having a channel therethrough, the channel having a first section, a second section and a third section, wherein the internal diameter of the second section is wider than the internal diameter of the first section and the second section;

a sleeve slidingly received in the channel of the housing, the sleeve having a ring extending outwardly from an outer surface thereof, the ring having an outer diameter larger than the internal diameter of the first section and the third section of the housing, and smaller than the internal diameter of the second section, by which the sleeve is slidingly retained in the housing;

the housing and sleeve co-operate to provide a valve passage through which fluid passes, the housing has at least one outlet which forms part of the valve passage when the valve is in an injection mode; wherein the sleeve is movable relative to the housing between a first position wherein the valve is in the injection mode for injecting fluid into the reservoir, and a second position wherein the valve is in an abstraction mode for abstracting fluid from the reservoir.

[0025] The present invention further provides a combined injection valve for injecting fluid into, and abstracting fluid from a reservoir, the valve comprises:

a hollow housing having a channel therethrough, the channel having at least a channel portion in which an inner surface is substantially continuous,

a sleeve slidingly received in the channel of the housing, the sleeve having an upper ring and a lower ring extending outwardly from an outer surface thereof, each ring having an outer diameter slightly smaller than the internal diameter of the channel portion;

the housing and sleeve co-operate to provide a valve passage through which fluid passes, the housing has at least one outlet which forms part of the valve passage when the valve is in an injection mode;

wherein the sleeve is movable relative to the housing between a first position wherein the valve is in the injection mode for injecting fluid into the reservoir, and a second position wherein the valve is in an abstraction mode for abstracting fluid from the reservoir.

[0026] Preferably a first end of the housing is adapted to be secured to a first pipe, and a second end of the housing is adapted to be secured to a pump.

[0027] A surface of the channel portion, an external surface of the sleeve and the upper and lower rings may define at least one annular chamber.

[0028] The at least one annular chamber may be sealingly isolated from the valve passage.

[0029] The at least one annular chamber may be adapted to receive/discharge a working fluid for moving the sleeve relative to the housing.

[0030] The present invention further provides a fluid system for injecting fluid into, and abstracting fluid from a reservoir, the fluid system comprises:

a pipe secured to a first end of a combined injection valve;

a pump secured to a second end of the valve;

a control means to control the operation of the valve;

the valve comprising a housing having a sleeve slidingly retained therein, the sleeve being movable relative to the housing between a first position wherein the valve is in an injection mode for injecting fluid into the reservoir, and a second position wherein the valve is in an abstraction mode for abstracting fluid from the reservoir.

[0031] The housing may provide one or more outlets in a sidewall thereof wherein the one or more outlets are open when the valve is in the injection mode and are closed when the valve is in the abstraction mode.

[0032] In one aspect of the invention the housing has one or more annular chambers incorporated in an internal wall thereof. One or more annular collars may extend outwardly from an outer surface of the sleeve and may be slidingly received in the chamber, such that the sleeve can move relative to the housing between the first position and the second position.

[0033] In another aspect of the invention, the sleeve provides one or more annular rings extending outwardly from the outer surface, the one or more annular rings forming one or more chambers with the continuous inner surface of the channel of the housing.

[0034] The control means may comprise a first fluid line and a second fluid line both in fluid communication with the one or more annular chambers, wherein co-ordinated movement of a working fluid through the first fluid line and second fluid line causes movement of the sleeve relative to the housing, selectively moving the valve between the injection mode and the abstraction mode.

[0035] Preferably the one or more annular collars of the sleeve are provided by an upper collar and a lower collar.

[0036] The valve may have a variable upper chamber portion defined by that portion of the chamber above the upper collar of the sleeve, a variable lower chamber portion defined by that portion of the chamber below the lower collar of the sleeve, and a fixed intermediate chamber portion defined by that portion of the chamber between the upper collar and the lower collar.

[0037] The first fluid line may be in fluid communication with the upper chamber portion,

[0038] The second fluid line may be in fluid communication with the lower chamber portion.

[0039] Preferably when the working fluid is injected into the upper chamber portion through the first fluid line, the sleeve is caused to move downwardly, increasing the volume of the upper chamber portion, and closing the outlets in the housing, while the working fluid in the lower chamber portion is caused to exit therefrom through the second fluid line, while the volume of the lower chamber portion decreases. When the sleeve closes the outlet, the valve is in the abstraction mode, ready for fluid to be abstracted from the reservoir.

[0040] To move the valve from the abstraction mode to the injection mode the reverse process takes place. Preferably when the working fluid is injected into the lower chamber portion through the second fluid line, the sleeve is caused to move upwardly, increasing the volume of the lower chamber portion, allowing the outlets in the housing to open, while the working fluid in the upper chamber portion is caused to exit therefrom through the first fluid line, while the volume of the upper chamber portion decreases.

[0041] Preferably the control means may incorporate one or more solenoids to control the sequential flow of working fluid to and from the upper and lower chamber portions of the valve.

[0042] The pump may incorporate a check valve to prevent the flow of fluid through the valve when the pump is off and the housing outlets are closed. The check valve may also prevent flow of fluid through the valve and through the pump when the housing outlets are open.

[0043] Preferably the control means allows the valve to be operated in a controlled manner to minimise the issues of irregular flow rates when the valve is in the injection mode.

[0044] The present invention further provides a fluid system comprising a valve as herein before described.

[0045] The present invention further provides a method of injecting fluid into a reservoir and abstracting fluid from the reservoir wherein the method comprises moving a sleeve within a housing of a valve, the valve being as hereinbefore described.

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is schematic of a fluid system according to a first embodiment of the present invention;

Figure 2 is a cross sectional side view of a valve shown in figure 1, the valve being in an injection mode;

Figure 3 is a view similar to figure 2 wherein the valve is in an abstraction mode;

Figure 4 is a cross sectional side view of a portion of an alternative valve, the valve being in an injection mode; and

Figure 5 is a view similar to figure 4 wherein the valve is in an abstraction mode.

[0047] In the drawings like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention.

DESCRIPTION OF EMBODIMENTS

[0048] According to an embodiment of the present invention, there is provided a valve which is used to control the flow of liquid, such as water, as it is injected into a borehole for the purpose of recharging a subterranean reservoir/aquifer. The valve is also designed to perform the abstraction of the liquid from the reservoir water, wherein the valve can selectively alternate between modes: injection and abstraction.

[0049] Fluid is often injected into or abstracted from reservoirs for various reasons. So that this can take place, a borehole 11 is first drilled through to a reservoir 13 before a borehole casing 15 is installed in the borehole 11, as shown figure 1. A fluid system 17 according to an embodiment of the present invention may then be installed for injecting and abstracting fluid from the reservoir 13.

[0050] The fluid system 17 comprises a valve 19, a first pipe, in the form of a riser 21, secured to a first end 23 of the valve 19, a pump 25 secured to a second end 27 of the valve 19, and a control means for operating the valve. The riser 21 is secured via a borehead 29 to headworks 31, through which fluid passes when either injecting fluid into, or abstracting fluid from the reservoir 13.

[0051] The configuration of the valve 19 is best shown in figures 2 and 3. Figure 2 represents the valve 19 when in an injection mode. In the injection mode fluid can be injected into the reservoir 13. The flow of fluid through the valve 19 when in the injection mode is indicated by arrows "A". Figure 3 represents the valve 19 when in an abstraction mode. In the abstraction mode fluid can be abstracted from the reservoir 13. The flow of fluid through the valve 19 when in the abstraction mode is indicated by arrows "B".

[0052] Referring to figures 2 and 3, the valve 19 comprises a housing 33 and a sleeve slidingly retained in the housing 33. In this embodiment both the housing 33 and sleeve 35 are hollow and tubular in shape, and co-operate to define a valve passage 37.

[0053] The housing 33 provides the first end 23 and second end 27 of the valve 19. The housing also provides a channel 39 along which the sleeve 35 slides. The channel 39 provides an inner wall section which presents a substantially continuous surface 43.

[0054] The inner surface 43 of the channel 39 of the housing 33 co-operates with the outer surface 49 of the sleeve 35 to define a chamber 51. Using seals 53, the chamber 51 is sealed relative to the valve passage 37.

[0055] The sleeve 35 has an upper collar/ring 45 and a lower collar/ring 47 in spaced relation, and extending outwardly from an outer surface 49 thereof into the chamber 51. Each ring 45, 47 has an outer diameter slightly smaller than the internal diameter of the channel 39 and divides the chamber 51 into three portions: an upper chamber portion , a lower chamber portion 57, and a fixed intermediate chamber portion 59.

[0056] The volume of the upper chamber portion 55 and the lower chamber portion 57 vary as a result of movement of the sleeve 35 relative to the housing 33. The variable upper chamber portion 55 is defined by that portion of the chamber above the upper ring 45 of the sleeve, while the variable lower chamber portion 57 is defined by that portion of the chamber below the lower ring 47 of the sleeve 35. The fixed intermediate chamber portion 59 is defined by that portion of the chamber between the upper ring 45 and the lower ring 47.

[0057] The volume of the upper chamber portion 55 varies between zero volume, as shown in figure 2, and its maximum volume, as shown in figure 3. Whereas the volume of the lower chamber portion 57 varies between its maximum volume, as shown in figure 2, and zero volume, as shown in figure 3

[0058] The housing 33 also provides a series of outlets 61 adjacent the second end 27 of the valve. These outlets 61 extend through the wall of the housing 33 from the channel to an outer surface 63 of the housing 33.

[0059] The control means comprises a control apparatus (not shown) which selectively operates solenoids (not shown) to regulate a working fluid 65 into and out of the chamber 51 to selective move the sleeve 35 relative to the housing 33.

[0060] The control means also comprises a first fluid line 67 which is in fluid communication with the upper chamber portion 55, and a second fluid line 69 which is in fluid communication with the lower chamber portion 57, wherein co-ordinated movement of the working fluid through the first fluid line 67 and second fluid line 69 cause movement of the sleeve 35 relative to the housing 33.

[0061] In operation, when the working fluid 65 is injected into the upper chamber portion through the first fluid line 67, the sleeve 35 is caused to move downwardly, increasing the volume of the upper chamber portion 55. As the sleeve 35 moves downwardly, a bottom portion 71 of the sleeve starts to obstruct and close the outlets 61 in the housing 33. The working fluid 65 in the lower chamber portion 57 is caused to exit therefrom through the second fluid line 69, and the volume of the lower chamber decreases. Eventually the bottom portion 71 of the sleeve 35 completely closes each outlet 61. When the sleeve is in this position, the valve 19 is in the abstraction mode, ready for the pump to be energised so that fluid can be abstracted from the reservoir 13.

[0062] To move the valve 19 from the abstraction mode to the injection mode the reverse process takes place. The working fluid 65 is injected into the lower chamber portion 57 through the second fluid line 69. This causes the sleeve 35 to move upwardly, increasing the volume of the lower chamber portion 57, allowing the outlets 61 in the housing to open. During this process the working fluid in the upper chamber portion 55 is caused to exit therefrom through the first fluid line 67, resulting in a decrease in the volume of the upper chamber portion 55. The outlets 61 open and fluid can be injected into the reservoir through the valve 19.

[0063] A valve according to a second embodiment of the invention is illustrated in figures 4 and 5.

[0064] The second embodiment provides a combined borehole injection valve 219 comprising a hollow tube like housing 1 adapted for connection to a borehole downpipe 2 at its upper end and a submersible electrically driven pump 3 at its lower end, a plurality of outlet openings 4 arranged around the lower wall of housing 1, a valve element 5 slidingly and sealingly mounted within the housing 1 the valve element 5 being provided with a circumferential collar 6 positioned within an enlarged chamber 7 of the housing 1, control tubes 8A and 8B provided to the enlarged chamber 7 and such that alternate admission and release of water in the control tubes 8A and 8B causes movement of the valve element 5 between the limits 7A and 7B of the chamber 7 causing the outlet openings 4 to be exposed or covered. The control tubes 8A and 8B being connected at surface level to the borehole feed water pipeline which is maintained at a moderate positive hydraulic head pressure thus providing the means to operate the valve element 5 thereby providing an effective combination injection valve which does not require a separate powered control system and avoids the potential for electrical failure.

[0065] Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention. The present invention is not to be limited in scope by any of the specific embodiments described herein. These embodiments are intended for the purpose of exemplification only. Functionally equivalent products, formulations and methods are clearly within the scope of the invention as described herein.

[0066] Reference to positional descriptions, such as lower and upper, are to be taken in context of the embodiments depicted in the figures, and are not to be taken as limiting the invention to the literal interpretation of the term but rather as would be understood by the skilled addressee.

[0067] Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0068] While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

[0069] Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0070] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms )"a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprise", "comprises," "comprising," "including," and "having," or variations thereof are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0071] The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0072] When an element or layer is referred to as being "on", "engaged to", "connected to" or "coupled to" another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to", "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

[0073] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0074] Spatially relative terms, such as "inner," "outer," "beneath", "below", "lower", "above", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0075] Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0076] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element or intervening elements may be present. As used herein the term "and/or" includes any and all combinations of one or more of the associated listed items.

Claims

1. A valve adapted to inject fluid into, and abstract fluid from a reservoir, the valve comprises:

a housing having a first end adapted to be secured to a first pipe, and a second end adapted to be in fluid communication with a pump;

a sleeve slidingly retained in the housing, the sleeve being movable relative to the housing between a first position wherein the valve is in an injection mode for injecting fluid into the reservoir, and a second position wherein the valve is in an abstraction mode for abstracting fluid from the reservoir.

2. The valve according to claim 1 wherein the housing and sleeve co operate to define a valve passage through the valve.

3. The valve according to claim 2 wherein the passage valve extends from the first end to the second end.

4. The valve according to claim 1 or 2 wherein the housing has a channel therethrough, wherein the sleeve is slidingly retained in the channel.

5. The valve according to claim 1, 2 or 3 wherein the housing provides one or more outlets adjacent the second end of the valve.

6. The valve according to claim 5 wherein the one or more outlets are in fluid communication with the valve passage when the valve is in the injection mode.

7. The valve according to claim 5 wherein the one or more outlets are not in fluid communication with the valve passage when the valve is in the abstraction mode.

8. The valve according to any one of claims 1 to 7 wherein the valve provides at least one chamber.

9. The valve according to claim 8 wherein the volume of the at least one chamber is adjustable to selectively move the sleeve relative to the housing.

10. The valve according to any one of claims 8 to 9 wherein the at least one chamber is in the form of an annular ring.

11. The valve according to any one of claims 8 to 10 wherein the at least one chamber is sealed from the valve passage.

12. The valve according to any one of claims 8 to 11 wherein the chamber is formed between the sleeve and the housing.

13. The valve according to any one of claims 8 to 12 when dependent on claim 10 wherein the two annular rings are in spaced apart relation.

14. The valve according to any one of claims 8 to 12 wherein the housing has an annular recess incorporated in an internal wall thereof.

15. The valve according to claim 14 wherein an outer portion of the sleeve is adapted to be slidingly received in the annular recess.

16. The valve according to claim 15 wherein the outer portion co-operates with the annular recess of the housing to define an uppermost position of the sleeve relative to the housing and a lowermost position of the sleeve relative to the housing.

17. The valve according to claim 15 or 16 wherein the outer portion of the sleeve is in the form of a projection extending outwardly from an outer surface of the sleeve.

18. The valve according to claim 17 wherein the outer portion is dimensioned to be wider than the internal diameter of the channel of the housing, and narrower than the internal diameter of the annular recess.

19. The valve according to claim 18 wherein the projection is in the form of an annular ring.

20. The valve according to claim 19 wherein the annular ring is formed in the outer surface of the housing.

21. The valve according to any one of claims 17 to 20 wherein the length of the projection is shorter than the length of the annular recess by an amount at least equal to the diameter of the outlets formed in the housing.

22. The valve according to any one of claims 8 to 12 wherein the sleeve provides one or more annular rings extending outwardly from the outer surface of the sleeve, the one or more annular rings forming one or more chambers with the continuous inner surface of the channel of the housing.

23. The valve according to any one of claims 8 to 22 wherein an upper portion of the chamber is adapted to receive and discharge a working fluid therefrom.

24. The valve according to any one of claims 8 to 23 wherein a lower portion of the chamber is adapted to discharge and receive the working fluid therefrom.

25. The valve according to any one of claims 8 to 24 wherein the valve is a combined injection valve.

26. A combined injection valve for injecting fluid into, and abstracting fluid from a reservoir, the valve comprises:

a sleeve slidingly received in the channel of the housing, the sleeve having a ring extending outwardly from an outer surface thereof, the ring having an outer diameter larger than the internal diameter of the first section and the third section of the housing, and smaller than the internal diameter of the second section, by which the sleeve is slidingly retained in the housing; the housing and sleeve co-operate to provide a valve passage through which fluid passes, the housing has at least one outlet which forms part of the valve passage when the valve is in an injection mode; wherein the sleeve is movable relative to the housing between a first position wherein the valve is in the injection mode for injecting fluid into the reservoir, and a second position wherein the valve is in an abstraction mode for abstracting fluid from the reservoir.

27. A combined injection valve for injecting fluid into, and abstracting fluid from a reservoir, the valve comprises:

28. The combined injection valve according to claims 26 or 27 wherein a first end of the housing is adapted to be secured to a first pipe, and a second end of the housing is adapted to be secured to a pump.

29. The combined injection valve according to claims 27 wherein a surface of the channel portion, an external surface of the sleeve and the upper and lower rings define at least one annular chamber.

30. The combined injection valve according to claims 29 wherein the at least one annular the chamber is sealingly isolated from the valve passage.

31. The combined injection valve according to claims 29 or 30 wherein the at least one annular chamber is adapted to receive/discharge a working fluid for moving the sleeve relative to the housing.

32. A fluid system for injecting fluid into, and abstracting fluid from a reservoir, the fluid system comprises:

a pipe secured to a first end of a combined injection valve;

a pump secured to a second end of the valve;

a control means to control the operation of the valve;

33. The fluid system according to claim 32 wherein the housing provides one or more outlets in a sidewall thereof, wherein the one or more outlets are open when the valve is in the injection mode and are closed when the valve is in the abstraction mode.

34. The fluid system according to claim 32 or 33 wherein the housing has one or more annular chambers incorporated in an internal wall thereof.

35. The fluid system according to claim 34 wherein one or more annular collars extend outwardly from an outer surface of the sleeve and are slidingly received in the chamber, such that the sleeve can move relative to the housing between the first position and the second position.

36. The fluid system according to claim 32 or 33 wherein the sleeve provides one or more annular rings extending outwardly from the outer surface, the one or more annular rings forming one or more chambers with the continuous inner surface of the channel of the housing.

37. The fluid system according to any one of claims 32 to 36 wherein the control means comprises a first fluid line and a second fluid line both in fluid communication with the one or more annular chambers, wherein co-ordinated movement of a working fluid through the first fluid line and second fluid line causes movement of the sleeve relative to the housing, selectively moving the valve between the injection mode and the abstraction mode.

38. The fluid system according to any one of claims 35 to 37 wherein the one or more annular collars of the sleeve are provided by an upper collar and a lower collar.

39. The fluid system according to claim 38 wherein the valve has a variable upper chamber portion defined by that portion of the chamber above the upper collar of the sleeve, a variable lower chamber portion defined by that portion of the chamber below the lower collar of the sleeve, and a fixed intermediate chamber portion defined by that portion of the chamber between the upper collar and the lower collar.

40. The fluid system according to claim 39 wherein the first fluid line is in fluid communication with the upper chamber portion.

41. The fluid system according to claim 39 or 40 wherein the second fluid line is in fluid communication with the lower chamber portion.

42. The fluid system according to claim 41 wherein when the working fluid is injected into the upper chamber portion through the first fluid line, the sleeve is caused to move downwardly, increasing the volume of the upper chamber portion, and closing the outlets in the housing, while the working fluid in the lower chamber portion is caused to exit therefrom through the second fluid line, while the volume of the lower chamber portion decreases; the valve being in the abstraction mode when the sleeve closes the outlet, ready for fluid to be abstracted from the reservoir.

43. The fluid system according to claim 41 wherein when the working fluid is injected into the lower chamber portion through the second fluid line, the sleeve is caused to move upwardly, increasing the volume of the lower chamber portion, allowing the outlets in the housing to open, while the working fluid in the upper chamber portion is caused to exit therefrom through the first fluid line, while the volume of the upper chamber portion decreases, the valve being in the injection mode when the sleeve opens the outlet, ready for fluid to be injected into the reservoir..

44. The fluid system according to any one of claims 32 to 43 wherein the control means incorporates one or more solenoids to control the sequential flow of working fluid to and from the upper and lower chamber portions of the valve.

45. The fluid system according to any one of claims 32 to 44 wherein the pump incorporates a check valve to prevent the flow of fluid through the valve when the pump is off and the housing outlets are closed.

46. The fluid system according to claim 45 wherein the check valve prevents the flow of fluid through the valve and through the pump when the housing outlets are open.

47. The fluid system according to any one of claims 32 to 46 wherein the control means allows the valve to be operated in a controlled manner to minimise the issues of irregular flow rates when the valve is in the injection mode.

48. A fluid system comprising a valve according to any one of claims 1 to 31.

49. A method of injecting fluid into a reservoir and abstracting fluid from the reservoir wherein the method comprises moving a sleeve within a housing of a valve, the valve according to any one of claims 1 to 31.