Anti-throttling subsurface injection safety valve

Abstract

Some implementations include a downhole valve configured for use inside a flow tube. The downhole valve may include a poppet configured to reciprocate on an internal centralizer to enable and disable flow in the flow tube. The downhole valve also may include a flow housing including one or more ports configured to convey a fluid around the poppet into a space between the flow housing and the flow tube to achieve a pressure drop upstream of the poppet.

Description

ANTI-THROTTLING SUBSURFACE INJECTION SAFETY VALVETECHNICAL FIELD

[0001] Some implementations relate to valves. More specifically, some implementations relate to valves that facilitate injection of fluids into underground geological formations.BACKGROUND

[0002] Various processes may involve injecting capture carbon dioxide (CO2) into underground geological formations. For example, carbon capture and storage (CCS) systems may capture and inject C02into an underground geological formation (such as a depleted oil and gas field, saline aquifer, or other formation). The CO2 may be permanently stored in the underground geological formation. CCS and other processes may utilize valves that facilitate injecting CO2 or other fluids into underground geological formations.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Implementations of the disclosure may be better understood by referencing the accompanying drawings.

[0004] Figure 1 is a sectional view of a subsurface injection safety valve.

[0005] Figure 2 is a sectional view of the valve residing inside a flow tube.

[0006] Figure 3 is a schematic depicting an example geothermal system.

[0007] Figure 4 is a flow diagram showing operations for controlling flow.DESCRIPTION OF IMPLEMENTATIONS

[0008] The description that follows may include example systems, methods, and techniques that embody implementations of the disclosure. However, this disclosure may be practiced without these specific details. For clarity, some well-known instruction instances, protocols, structures, and techniques may not be shown in detail.Overview

[0009] Some traditional subsurface injection safety valves (also referred to herein as “valves”) may include spring-actuated closure mechanisms that reciprocate between open and closedpositions. During operation, the closure mechanism may uncontrollably throttle between the open and closed positions. Throttling may result in failure of the valve’s closure seal mechanism, its closure spring, and more. In traditional valves, such throttling may arise from fluctuations of the injected fluid properties and / or flow rates. Throttling may be more severe for carbon capture and storage (CCS) applications because changes in pressure, temperature, or flow rate may change the phase of the CO2 resulting in wide range of pressure drop to hold open the closure mechanism. Additionally, the need to maintain a large flow area through the injection valve to mitigate erosion issues coupled with the ty pical injection rates for CO2 may lead to the use of a relatively weak closure spring (in traditional valves). With a relatively weak closure force, the closure spring may not be able to overcome a mechanical anti-throttling / hold-open feature when injection flow ceases, so a traditional valve may fail in the open position.

[0010] Some implementations include a valve and closure mechanism configured to reduce throttling and failure in the open position. In some implementations, the valve includes a closure mechanism that stops on a metal -to-metal (MTM) seal upstream of a closure spring chamber to create a large piston area acting on the closure mechanism. The valve’s closure spring chamber may be ported such that injection flow passing over the outside diameter of the spring chamber creates a low pressure inside the spring chamber while flow is present. Increased flow velocity in the outside diameter of the spring chamber may result in reduction of fluid pressure (venturi effect). This may increase a pressure differential acting across the MTM dow n stop. The increased pressure differential may cause a hold-open force on the closure mechanism while injection flow is present. Due to the large piston area of the MTM seal, the hold-open force may exceed the spring force under a wide range of flow conditions ensuring that the injection valve is held in the fully open position. In some implementations, the hold-open force for the closure mechanism is activated only when injection How is present. When injection flow' is stopped, the hold-open force may go to zero, allowing a relatively weak closure spring to close the injection valve.Example Implementations

[0011] Figure 1 is a sectional view of a subsurface injection safety valve. The valve 100 may be coupled with an upper subassembly 120 and a bottom subassembly 118 and may reside inside a flow' tube (not show n in Figure 1) (see discussion of Figure 2). The valve 100 may include a spring 104 configured to move a poppet 102 between an open position and a closed position. In Figure 1, the valve 100 is in the closed position, where the poppet 102 is in contact with a metal - to-metal (MTM) seal 122 to fluidically seal off flow' in any direction. Hence, in the closedposition, the valve 100 disables both downstream and upstream flow. In the open position, the poppet 102 is not in contact with the MTM seal 122 and downstream flow is enabled.

[0012] When no fluid (such as CO2) is being injected, the spring 104 may apply a closing force to hold the poppet 102 in contact with the MTM seal 122. thereby disabling flow through the valve 100. When fluid is being injected, pressure may overcome the closing force and move the valve 100 into the open position (poppet 102 out of contact with the MTM seal 122). To facilitate opening, the valve 100 may include a spring chamber 128 that includes flow ports 126. The flow ports 126 may convey fluid through the spring chamber 128 into an annular space between the valve 100 and a flow tube (not shown in Figure 1; see discussion of Figure 2). Fluid flowing through the flow ports 126 may cause low pressure inside the spring chamber 128 while flow is present. That is, increased flow velocity in the outside diameter of the spring chamber 128 (i.e., in the above-noted annular space) may reduce pressure inside the spring chamber 128 (venturi effect). This may increase a pressure differential acting across the MTM seal 122. The increased pressure differential may cause a hold-open force on the valve 100 while injection flow is present. Due to the large piston area of the MTM seal 122, the hold-open force may exceed the spring’s closing force under a wide range of flow conditions ensuring that the valve 100 is held in the fully open position. In some implementations, the hold-open force for the valve 100 is activated only when injection flow is present. When injection flow ceases, the holdopen force may go to zero, allowing a relatively weak closing force from the spring 104 to close the valve 100.

[0013] As shown, the spring 104 may be coiled around an internal centralizer 116 and coupled with a spring cap 106. A spring housing 108 may house at least a portion of the spring 104 and internal centralizer 116. An external centralizer 112 may house portions of the spring housing 108, spring 104, and internal centralizer 116. The external centralizer 112 may be housed inside a flow housing 114. The flow housing 114 may include the flow ports 126 and clean out ports 124. A skirt 110 may be connected to the poppet 102, where the skirt 110 and poppet 102 reciprocate inside the flow housing 114 on the external centralizer 112.

[0014] Figure 2 is a sectional view of the valve residing inside a flow tube 200. In Figure 2, the valve 100 is in the open position. A flow path 202 may convey fluid (such as CO2) through one or more components that reside inside the flow tube 200. The flow path 202 may run through the upper subassembly 120 and into the spring chamber 128 of the valve 100. The flow path 202 may continue through the flow ports 126 into an annular space 204 between the flow housing 114 and the flow tube 200. The flow path 202 may continue downstream in the flow tube 200.

[0015] Before fluid is injected into the flow path 202. the valve 100 may be in the closed position (see Figure 1). As fluid is injected into the flow path 202, the fluid may flow into the spring chamber 128 and push open the valve’s closure mechanism (poppet 102, spring 104, and more). As the poppet 102 moves downstream, the flow ports 126 may be exposed, thereby allowing the fluid to flow downstream into the annular space 204. As fluid flows downstream, pressure upstream of the poppet 102 may drop. Despite the pressure drop, the flow may create a hold-open force that holds the valve’s closure mechanism in a fully open position. Because the pressure drops upstream of poppet 102, some implementations of the valve 100 may require less closing force to move the closure mechanism into the fully closed position than traditional valves that do not exhibit such a pressure drop. Hence, the spring 104 may be configured to exert less closing force than springs in traditional valves. A lower closing force may reduce throttling of the closure mechanism, thereby avoiding failures of the spring 104, MTM seal 122, and other components.

[0016] As shown in Figure 2, in the open position, the spring 104 may be compressed and the poppet 102 and skirt 110 may be further dow nstream than the closed position. In some implementations, sizing of the flow7housing 114 may depend on the inner diameter of the flow tube 200. For larger flow tubes, the flow housing f 14 may have a larger outer diameter. The outer diameter may be selected to achieve a particular pressure drop downstream of the poppet 102 (as described herein).

[0017] With the benefit of this disclosure, one of ordinary skill in the art would understand that some implementations may include configurations in which the venturi effect causes a force opposite the closing force of the spring 104. Although the discussion of Figures 1 and 2 refer to a spring 104, some implementations may utilize any suitable actuator configured to provide a closing force (as described herein).Example Environment

[0018] Implementations may be deployed in any suitable environment. For example, some implementations may be deployed in a geothermal system. Figure 3 is a schematic depicting an example geothermal system. More specifically, Figure 3 is a schematic of a geothermal system 300 that includes a production wellbore 302 and an injection wellbore 310 in a subsurface formation 301. In some implementations, a working fluid may be obtained from a source such as a power plant, a carbon capture plant, etc. The working fluid may include a supercritical fluid, such as supercritical CO2. Injection components 316 (such as a compressor, pump, etc.)may pump the working fluid into the casing 312 of the injection wellbore 310, via the wellhead 314, to inj ect the working fluid into the subsurface formation 301 .

[0019] A subsurface injection safety valve 100 (“valve 100"’) may be disposed in the injection wellbore 310. The valve 100 may include any one or more of the inventive aspects described herein.

[0020] The injection wellbore 310 also may include one or more inflow control devices 320-324 disposed in the injection wellbore 310. The inflow control devices 320-124 may include a nozzle inflow control device and / or other suitable inflow control devices configured to regulate the flow of the working fluid into the subsurface formation. In some implementations, there may be perforations, screens, or any other suitable wellbore completion tools and / or configurations that allow the injected working fluid to flow into the subsurface formation 301. In some implementations, the injection wellbore 310 may include packers 326 and 328 to control the flow of the working fluid to the inflow control devices 320-324. The packers 326 and 328 may include any suitable packer type for zonal isolation in a wellbore such as a swell metal packer.

[0021] In some implementations, the subsurface formation may include fractures (artificial and / or natural). The working fluid, when injected into the subsurface formation 301, via the injection wellbore 310, may flow through said fractures towards the production wellbore 302. When exposed to the subsurface formation 301, the temperature of the working fluid mayincrease due to the geothermal heat of the subsurface formation 301. In some implementations, the working fluid may short circuit through the fractures of the subsurface formation, limiting the exposure of the working fluid to the heat of the subsurface formation 301. Alternatively, or in addition to, one or more areas within the subsurface formation 301 may be cooled due to increased exposure to the working fluid.

[0022] In some implementations, the production wellbore 302 may include one or more packers, such as packers 336 and 338, positioned between the flow control assemblies 330-334. The packers 336 and 138 may create zonal isolation between the flow control assemblies 130-134. The packers 336, 338 may be any suitable packer configured for zonal isolation, such as a swell metal packer.

[0023] Once the working fluid flows into the casing 304, via the one or more flow control assemblies 330-334, the working fluid may flow to the surface 311 where it may flow through the wellhead 306 of the production wellbore 302 to a thermal energy recovery system 308. The thermal energy- recovery- system 308 may- include a steam plant, thermoelectric generators, or anyother suitable systems configured to utilize the thermal energy recovered in the working fluid. In some implementations, the thermal energy recovery system 308 may be a part of the same system as the injection components 316. For example, the thermal energy recovery system 308 and the injection components 316 may both be a part of a steam plant. The heated working fluid may be produced from the production wellbore 302 and sent to the steam plant. Once cooled, the working fluid may then flow to a compressor at the steam plant which may then return the cooled fluid back to the injection wellbore 310 for injection.

[0024] The geothermal system 300 depicted in Figure 3 depicts two horizontal wellbores. The control of the flow of a working fluid based on the working fluid density, via one or more flow control assemblies, may be applicable to any other suitable wellbore configurations utilized in geothermal operations. For example, one or more of the wellbores (either the production well, injection well(s), or both) may be vertical, there may be multiple injection wells offset to the production well, there may only be a single wellbore that acts as the injection well and the production well (i.e., a geothermal energy storage system), etc.

[0025] The geothermal system 300 may include a computer 370 that may be communicatively coupled to other parts of the geothermal system 300. The computer 370 may be local or remote to the geothermal system 300. A processor of the computer 370 may perform simulations (as further described below). In some implementations, the processor of the computer 170 may control geothermal operations of the geothermal system 300 or subsequent geothermal operations of other wellbores. For instance, the processor of the computer 370 may determine the density of the working fluid based on measurements obtained from the flow control assemblies 330-334 and control the flow control assemblies 330-334 based on the density of the working fluid.

[0026] Figure 4 is a flow diagram showing operations for controlling flow. At block 402, a method may move, in response to injection of a fluid into the flow tube, a poppet of a valve into a fully open position to enable flow of the fluid. At block 404, the method may convey, via one or more flow ports, the fluid around the poppet into a space between a flow housing of the valve and the flow tube to achieve a pressure drop upstream of the poppet.

[0027] Figures 1-4 and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations may perform additionaloperations, fewer operations, operations in parallel or in a different order, and some operations differently. Some implementations may perform the operations with different components.

[0028] As used herein, a phrase referring to “at least one of’ a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b. or c” is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

[0029] Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art. and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be interpreted the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

[0030] Certain features that are described in this specification in the context of separate implementations also may be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also may be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination may in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0031] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.Example Clauses

[0032] Some implementations may include the following clauses.

[0033] Clause 1 : A downhole valve configured for use inside a flow' tube, the downhole valve comprising: a poppet configured to reciprocate on an internal centralizer to enable and disable flow in the flow tube; and a flow housing including one or more ports configured to convey a fluid around the poppet into a space between the flow housing and the flow' tube to achieve a pressure drop upstream of the poppet.

[0034] Clause 2: The downhole valve of clause 1 further including a spring coupled with the internal centralizer and configured to exert a selected closing force on the poppet, wherein the selected closing force and the pressure drop coordinate to reduce throttling of the poppet and spring.

[0035] Clause 3: The downhole valve of any one or more of clauses 1-2 further comprising an actuator configured to move the poppet to enable the flow of the fluid in response to injection of the fluid in the flow tube; and move the poppet to disable backflow in response to cessation of the flow of the fluid.

[0036] Clause 4: The downhole valve of any one or more of clauses 1-3, wherein the actuator is a coiled spring

[0037] Clause 5: The downhole valve of any one or more of clauses 1-4, wherein the poppet is further configured to disable the flow by contact with a metal sealing surface inside the flow tube.

[0038] Clause 6: The downhole valve of any one or more of clauses 1-5, wherein a size of the flow housing depends on an inner diameter of the flow tube, and wherein the flow housing is sized to achieve the pressure drop upstream of the poppet.

[0039] Clause 7: The downhole valve of any one or more of clauses 1-6, wherein the fluid includes carbon dioxide.

[0040] Clause 8: The downhole valve of any one or more of clauses 1-7, wherein the flow tube is part of a carbon capture and storage system.

[0041] Clause 9: A method for controlling flow in flow tube, the method comprising: moving, in response to injection of a fluid into the flow tube, a poppet of a valve into a fully open position to enable flow7of the fluid; and conveying, via one or more flow ports, the fluid around the poppet into a space betw een a flow housing of the valve and the flow' tube to achieve a pressure drop upstream of the poppet.

[0042] Clause 10: The method of clause 9 further compnsing exerting, via an actuator, a closing force on the poppet to move the poppet into a fully closed position, wherein the closing force and the pressure drop coordinate to reduce throttling of the poppet and the actuator.

[0043] Clause 11 : The method of any one or more of clauses 9-10, wherein the poppet is coupled with the actuator, and wherein the actuator reciprocates the poppet on an internal centralized between the fully open position and the fully closed position.

[0044] Clause 12: The method of any one or more of clauses 9-11, wherein the actuator is a spring.

[0045] Clause 13: The method of any one or more of clauses 9-12, wherein a size of the flow housing depends on an inner diameter of the flow tube, and wherein the flow housing is sized to achieve the pressure drop upstream of the poppet.

[0046] Clause 14: The method of any one or more of clauses 9-13, wherein the fluid includes supercritical carbon dioxide.

[0047] Clause 1 : A system comprising: a flow tube; a downhole valve fluidically coupled with the flow tube, the downhole valve including a poppet configured to reciprocate on an internal centralizer to enable and disable flow in the flow tube; and a flow housing including one or more ports configured to convey a fluid around the poppet into a space between the flow housing and the flow tube to achieve a pressure drop upstream of the poppet.

[0048] Clause 16: The system of clause 15, the downhole valve further including a spring coupled with the internal centralizer and configured to exert a selected closing force on the poppet, wherein the selected closing force and the pressure drop coordinate to reduce throttling of the poppet and spring.

[0049] Clause 17: The system of any one or more of clauses 15-16, the downhole valve of claim 1 further comprising: an actuator configured to move the poppet to enable the flow of the fluid in response to injection of the fluid in the flow7tube; and move the poppet to disable backflow7in response to cessation of the flow of the fluid.

[0050] Clause 18: The system of any one or more of clauses 15-17, wherein the actuator is a coiled spring.

[0051] Clause 19: The system of any one or more of clauses 15-18. wherein the poppet is further configured to disable the flow by contact with a metal sealing surface inside the flow7tube.

[0052] Clause 20: The system of any one or more of clauses 15-19, wherein a size of the flow housing depends on an inner diameter of the flow tube, and wherein the flow housing is sized to achieve the pressure drop upstream of the poppet.

Claims

2024-INV-l 12517- WOOlCLAIMSWhat is claimed is:

1. A downhole valve configured for use inside a flow tube, the downhole valve comprising: a poppet configured to reciprocate on an internal centralizer to enable and disable flow in the flow tube; and a flow housing including one or more ports configured to convey a fluid around the poppet into a space between the flow housing and the flow tube to achieve a pressure drop upstream of the poppet.

2. The downhole valve of claim 1 further including: a spring coupled with the internal centralizer and configured to exert a selected closing force on the poppet, wherein the selected closing force and the pressure drop coordinate to reduce throttling of the poppet and spring.

3. The downhole valve of claim 1 further comprising: an actuator configured to move the poppet to enable the flow of the fluid in response to injection of the fluid in the flow tube; and move the poppet to disable backflow in response to cessation of the flow of the fluid.

4. The downhole valve of claim 3, wherein the actuator is a coiled spring.

5. The downhole valve of claim 1 , wherein the poppet is further configured to disable the flow by contact with a metal sealing surface inside the flow tube.

6. The downhole valve of claim 1, wherein a size of the flow housing depends on an inner diameter of the flow tube, and wherein the flow housing is sized to achieve the pressure drop upstream of the poppet.

7. The downhole valve of claim 1, wherein the fluid includes carbon dioxide.2024-INV-l 12517- WOOl8. The downhole valve of claim 1, wherein the flow tube is part of a carbon capture and storage system.

9. A method for controlling flow in flow tube, the method comprising: moving, in response to injection of a fluid into the flow tube, a poppet of a valve into a fully open position to enable flow of the fluid; and conveying, via one or more flow ports, the fluid around the poppet into a space between a flow housing of the valve and the flow tube to achieve a pressure drop upstream of the poppet.

10. The method of claim 9 further comprising: exerting, via an actuator, a closing force on the poppet to move the poppet into a fully closed position, wherein the closing force and the pressure drop coordinate to reduce throttling of the poppet and the actuator.

11. The method of claim 10, wherein the poppet is coupled with the actuator, and wherein the actuator reciprocates the poppet on an internal centralized between the fully open position and the fully closed position.

12. The method of claim 10, wherein the actuator is a spring.

13. The method of claim 9, wherein a size of the flow housing depends on an inner diameter of the flow tube, and wherein the flow housing is sized to achieve the pressure drop upstream of the poppet.

14. The method of claim 9, wherein the fluid includes supercritical carbon dioxide.

15. A system comprising: a flow tube; a downhole valve fluidically coupled with the flow tube, the downhole valve including a poppet configured to reciprocate on an internal centralizer to enable and disable flow in the flow tube; and a flow housing including one or more ports configured to convey a fluid around the poppet into a space between the flow housing and the flow tube to achieve a pressure drop upstream of the poppet.2024-INV-l 12517- WOOl16. The system of claim 15, the downhole valve further including: a spring coupled with the internal centralizer and configured to exert a selected closing force on the poppet, wherein the selected closing force and the pressure drop coordinate to reduce throttling of the poppet and spring.

17. The system of claim 15 further comprising: an actuator configured to move the poppet to enable the flow of the fluid in response to injection of the fluid in the flow tube; and move the poppet to disable backflow in response to cessation of the flow of the fluid.

18. The system of claim 17, wherein the actuator is a coiled spring.

19. The system of claim 15, wherein the poppet is further configured to disable the flow by contact with a metal sealing surface inside the flow tube.

20. The system of claim 15, wherein a size of the flow housing depends on an inner diameter of the flow tube, and wherein the flow housing is sized to achieve the pressure drop upstream of the poppet.

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