WO2024130174A1 - Adjustable force safety valve systems and methods - Google Patents

Abstract

A safety valve of a well string may include a fluid conduit, disposed about an axis, for conveying a fluid through the safety valve and a valve closure member articulatable between a first state and a second state to selectively block a flow of the fluid through the fluid conduit. The safety valve may also include a power spring to bias the valve closure member toward the first state via a power spring force, a piston to operatively overcome the power spring force and articulate the valve closure member toward the second state, and an adjustable stop disposed at one of multiple different positions within the safety valve such that the power spring is compressed between the piston and the adjustable stop. Moreover, the power spring force may be different at the different positions of the adjustable stop.

Description

ADJUSTABLE FORCE SAFETY VALVE SYSTEMS AND METHODS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a Patent Cooperation Treaty (PCT) application claiming priority to and the benefit of India Provisional Application No. 202221072942, entitled “SPRING SYSTEM FOR A SAFETY VALVE,” filed December 16, 2022, which is hereby incorporated by reference in its entirety for all purposes.

BACKGROUND

[0002] This disclosure relates to downhole tool strings and valves thereof. In particular, the present disclosure relates to a valve, such as a safety valve, with an adjustable closing/opening force.

[0003] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as an admission of any kind.

[0004] The extraction of natural resources such as hydrocarbons from a geological formation is typically a multi-step endeavor utilizing a variety of tools and techniques. In general, wells to extract resources include a drilled wellbore into which downhole tools are deployed. For example, drilling and logging may be performed to create a wellbore into a geological formation and analyze the characteristics thereof, and well completion may be obtained when piping is put in place to allow for the production of resources from the geological formation.

[0005] In the various stages of the preparation and extraction, one or more valves may be utilized to selectively isolate or couple different portions of the wellbore and/or piping (e.g., production piping, drilling mud piping, etc.). Furthermore, different types of valves may be actuated in different manners (e.g., electrically, mechanically, hydraulically, etc.) and/or have different characteristics for use in a broad range of downhole applications including prevention of fluid loss, lateral and/or depth isolation, to control other downhole tools, etc. For example, safety valves may be designed to have a default state (e.g., open or closed) when not actively actuated.

[0006] Safety valves are generally utilized where a default state (e.g., open or closed) of the valve is to be desired if control of the valve is removed. In some scenarios, this may be to avoid a hazardous condition and/or to promote the efficiency /efficacy of well completion. Furthermore, in some scenarios, safety valves may be held to one or more standards, such as set by the American Petroleum Institute (API). For example, API Specification 14A outlines certain standards for subsurface safety valve equipment.

[0007] In general, a safety valve includes a blocking mechanism (e.g., valve closure member, valve element, etc.) that is held in a state (e.g., closed) due to a potential energy force of a power spring. For example, a power spring may maintain a safety valve in a closed state until a force greater than the potential energy force of the power spring is applied (e.g., via an electrical, mechanical, or hydraulic actuator) forcing the safety valve into an open state. However, due to the variations in downhole environments (e.g., temperature, pressure, etc.) the power spring force (e.g., potential energy force) of a particular safety valve may be suitable at one location (e.g., depth) and unsuitable in another location (e.g., a different depth). For example, the relative operating pressures of hydraulic systems, which may be utilized to actuate the safety valve, may be different at different depths and, therefore, different power spring forces may be utilized. Typically, different safety valves are designed with different power springs to accommodate the different depths (e.g., pressures) encountered downhole. However, having multiple different types and/or models of safety valves may be cumbersome, frustrating, and/or lead to logistical inefficiencies. As such, it is presently recognized that a single safety valve that is adjustable for different depths (e.g., pressures and power spring forces) may provide increased flexibility, consolidation of parts, and increased efficiency in time, cost, and/or labor. SUMMARY

[0008] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0009] Indeed, in one example, a safety valve of a well string may include a fluid conduit, disposed about an axis, for conveying a fluid through the safety valve and a valve closure member articulatable between a first state and a second state to selectively block a flow of the fluid through the fluid conduit. The safety valve may also include a power spring to bias the valve closure member toward the first state via a power spring force, a piston to operatively overcome the power spring force and articulate the valve closure member toward the second state, and an adjustable stop disposed at one of multiple different positions within the safety valve such that the power spring is compressed between the piston and the adjustable stop. Moreover, the power spring force may be different at the different positions of the adjustable stop.

[0010] In another embodiment, a method may include adjusting a position of an annular adjustable stop of a power spring of a safety valve in an axial direction relative to an axis. The annular adjustable stop may be disposed circumferentially about the axis, the power spring may be disposed between an actuatable piston and the adjustable stop, and the position of the annular adjustable stop may correspond to a biasing force of the power spring to maintain the safety valve in a closed position. Additionally, the method may include conveying the safety valve into a wellbore at a depth corresponding to the biasing force, and applying a hydraulic pressure to a piston chamber, having the actuatable piston disposed therein, such that a hydraulic force on the piston is greater than biasing force to facilitate transitioning the safety valve from the closed state to an open state.

[0011] In another embodiment, a safety valve adjusting tool may include an outer annular assembly configured to mechanically couple to a safety valve and a collet engagement assembly configured to be axially inserted into the safety valve. The collet engagement assembly may include a collet dog that selectively engages a collet of an adjustable stop of the safety valve. An axial position of the adjustable stop within the safety valve may correspond to an amount of a power spring force that biases a valve closure member to a closed state. Additionally, the collet dog may be axially adjustable relative to the outer annular assembly such that an axial movement of the collet dog, relative to the outer annular assembly, operatively changes the axial position of the adjustable stop within the safety valve.

[0012] Various refinements of the features noted above may be undertaken in relation to various aspects of the present disclosure. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. The brief summary presented above is intended to familiarize the reader with certain aspects and contexts of embodiments of the present disclosure without limitation to the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

[0014] FIG. 1 is an example of a well system with a well string having an adjustable safety valve deployed in a wellbore of a geological formation, in accordance with an embodiment;

[0015] FIG. 2 is a cross-sectional schematic diagram of a ratcheting adjustable safety valve, in accordance with an embodiment;

[0016] FIG. 3 is a partial cross-sectional schematic diagram of the ratcheting adjustable safety valve of FIG. 2 with an actuated adjustment piston, in accordance with an embodiment;

[0017] FIG. 4 is a partial cross-sectional schematic diagram of the ratcheting adjustable safety valve of FIG. 2 with a moved adjustable stop and non-actuated adjustment piston, in accordance with an embodiment; [0018] FIG. 5 is a flowchart of an example process for adjusting and utilizing the ratcheting adjustable safety valve of FIG. 2, in accordance with an embodiment;

[0019] FIG. 6 is a cross-sectional schematic diagram of a bidirectional adjustable safety valve, in accordance with an embodiment;

[0020] FIG. 7 is a cross-sectional schematic diagram of the bidirectional adjustable safety valve of FIG. 6 with a decoupled split flow tube, in accordance with an embodiment;

[0021] FIG. 8 is a cross-sectional schematic diagram of the bidirectional adjustable safety valve of FIG. 6 with an adjustment tool disposed therein, in accordance with an embodiment;

[0022] FIG. 9 is a cross-sectional schematic diagram of the bidirectional adjustable safety valve of FIG. 6 with an adjustment tool disposed therein and engaging a collet holder, in accordance with an embodiment;

[0023] FIG. 10 is a partial cross-sectional schematic diagram of the bidirectional adjustable safety valve of FIG. 6 with an adjustment tool disposed therein having a collet holder engagement assembly, in accordance with an embodiment;

[0024] FIG. 11 is a partial cross-sectional schematic diagram of the bidirectional adjustable safety valve of FIG. 6 with an adjustment tool disposed therein having a locking engagement assembly, in accordance with an embodiment;

[0025] FIG. 12 is a cross-sectional schematic diagram of the bidirectional adjustable safety valve of FIG. 6 with an adjustment tool disposed therein having a collet engagement assembly, in accordance with an embodiment;

[0026] FIG. 13 is a cross-sectional schematic diagram of the bidirectional adjustable safety valve of FIG. 6 with an adjustment tool disposed therein and having articulated a collet to a different position, in accordance with an embodiment; and

[0027] FIG. 14 is a flowchart of an example process for adjusting and utilizing the bidirectional adjustable safety valve of FIG. 6, in accordance with an embodiment. DETAILED DESCRIPTION

[0028] One or more specific embodiments of the present disclosure will be described below. These described embodiments are examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, the features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0029] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0030] The oil and gas industry includes a number of sub-industries, such as exploration, drilling, logging, extraction, transportation, refinement, retail, and so forth. During exploration and drilling, wellbores may be drilled into the ground for reasons that may include discovery, observation, or extraction of resources. These resources may include oil, gas, water, or any other combination of elements within the ground.

[0031] Wellbores, sometimes called boreholes, may be straight or curved holes drilled into the ground from which resources may be discovered, observed, and/or extracted. During and/or after the establishment of a wellbore, well logging may be practiced. Well logging may include making a detailed record of the geological formations penetrated by a wellbore, and is generally part of the discovery and observation of resources. In general, well logging may provide the basis for choosing to perform well completion. Well completion may include outfitting of the wellbore with equipment to facilitate production of reservoir fluids (e.g., hydrocarbons or other resource of interest). For example, piping may provide a conduit for carrying reservoir fluids to the surface and/or to allow for pumped fluid from the surface to enter the wellbore and/or pressurize the piping. Valves may be utilized to isolate different portions of the wellbore and/or piping, such as to optimize production and/or ease completion of the wellbore. As should be appreciated, pipes and valves (e.g., safety valves) may be utilized in well strings (well completion string, bottom hole assembly (BHA), well logging string, etc.) for any suitable purpose during drilling, logging, and/or production.

[0032] In general, safety valves may be utilized where a default state (e.g., open or closed) of the valve is desired if control of the valve is removed. For example, the default state (e.g., failsafe state) may be set to avoid a hazardous condition and/or to promote the efficiency /efficacy of a well operation. Furthermore, in some scenarios, safety valves may be held to one or more standards, such as the American Petroleum Institute (API) Specification 14A, which outlines certain standards for subsurface safety valve equipment. As used herein, safety valves may or may not connotate a safety hazard condition, but rather refer to a valve having a default state (e g., a fail-safe state). Furthermore, as discussed herein, the default state of a safety valve may be the open state or the closed state. While certain discussions or illustrations may refer to safety valves that default in the closed state, as should be appreciated, such is given as non-limiting examples, and the default state may be different while still employing the techniques discussed herein.

[0033] In general, a safety valve includes a blocking mechanism (e.g., flapper, valve stem, piston, or other articulating component) that is held in a default state (e.g., open or closed) by a power spring. For example, a power spring may maintain a safety valve in a closed state until an applied force overcomes the power spring force (e.g., the potential energy force of the power spring). In some embodiments, the applied force may be applied via an electrical, mechanical, or hydraulic actuator forcing the safety valve into an open state. For example, a hydraulic line may be pressurized (e.g., via a pump at the surface of the wellbore) to force a piston of the safety valve to overcome the power spring force and actuate (e.g., open or close) the valve. When the applied force is removed, the power spring may restore the blocking mechanism to the default state. [0034] However, at different depths of the wellbore, the same hydraulic pressure applied at the surface may correspond to a wide range of hydraulic pressures at the piston. For example, the hydrostatic pressure of the hydraulic fluid may increase as depth increases, meaning that a power spring force suitable (e.g., properly balanced for controllability) at one depth may be too strong at a depth closer to the surface or not strong enough at a depth deeper into the wellbore.

Typically, different safety valves are designed with different power springs to accommodate the different depths (e.g., pressures) encountered downhole, leading to an array of different models of safety valves for a single wellbore. However, aspects of the present disclosure include adjustable safety valves that can be adapted for use at different depths (e.g., operating pressures). Furthermore, such adjustable safety valves may be adjustable without breaking body connections thereof and satisfy one or more standards, such as API 14A. Such adjustability may provide increased flexibility, consolidation of parts, and increased efficiency in time, cost, and/or labor at a well site.

[0035] As discussed herein, a safety valve may utilize a power spring that abuts an actuatable piston that, when actuated, overcomes the power spring force and opens the safety valve. The opposite end of the power spring may abut an adjustable stop to alter the power spring force and suitable working depth of the adjustable safety valve. As should be appreciated, the power spring force may be approximately proportional to the compressed or stretched distance of the power spring from a state of equilibrium. In other words, by adjusting the compression (or expansion) of the power spring, the power spring force may be adjusted. As such, the adjustable stop, opposite the actuatable piston end of the power spring, may be moved to calibrate the adjustable safety valve for different depths and/or operating pressures.

[0036] With the foregoing in mind, FIG. 1 illustrates an example of a well system 10 with a well string 12 (e.g., well completion string, bottom hole assembly (BHA), well logging string, etc.) having an adjustable safety valve 14 deployed in a wellbore 16 of a geological formation 18. The adjustable safety valve 14 may include an actuatable blocking mechanism 20 (e.g., flapper, valve stem, piston, or other articulating component), which may also be described as a valve closure member or valve element, to selectively facilitate a flow of fluids (e.g., formation fluid, fluid pumped from the surface of the geological formation 18, or combination thereof) through piping 22 between the surface 24 and downhole 26 environments and/or between different sections (e.g., laterally and/or vertically separated portions) of the wellbore 16. Additionally, the adjustable safety valve 14 may maintain the blocking mechanism 20 in a default state (e.g., open or closed) when not positively actuated via an applied force. Furthermore, a wellhead 28 and/or surface equipment 30 may be disposed at the surface 24 of the well system 10. As should be appreciated, the wellhead 28 may include or interface with surface equipment 30 to control, monitor, or otherwise work in conjunction with the well string 12. For example, the surface equipment 30 may include one or more sensors, one or more pumps, one or more valves, communication equipment, winch or other relaying systems, mechanical connections with the well string 12, fluid connections with the well string 12, and/or electrical connections with the well string 12.

[0037] Additionally, in some embodiments, the well system 10 may include a liner or casing 32 along the sidewall of the wellbore 16, which may include pipe, cement, and/or other materials. Furthermore, the wellbore 16 (e.g., with or without a casing 32) may form an annulus 34 around the piping 22 and/or other components of the well string 12. In some embodiments, the well string 12 may include additional components such as a packer 36, which may form a seal in the annulus 34 separating sections of the wellbore 16. Moreover, while depicted as a land- based well system 10, in some embodiments, the techniques discussed herein may also be utilized in subsea and/or offshore applications.

[0038] The well string 12 may receive energy from a downhole power source or from the surface equipment 30. Moreover, in some embodiments, the surface equipment 30 may send control signals to the well string 12 to facilitate operation of the well string 12. For example, the nature of the control signals may be electric, electromagnetic, acoustic, optical, chemical, a series of pressure pulses, a pressure differential, and/or a temperature differential. Moreover, in some embodiments, a data processing system 38 may be implemented as part of and/or coupled to the surface equipment 30 and/or well string 12 to control operations of the surface equipment 30 and well string 12. The data processing system 38 may be any electronic data processing system that can be used to carry out the systems and methods of this disclosure. For example, the data processing system 38 may include a processor 40, which may execute instructions stored in memory 42 and/or storage 44. As such, the memory 42 and/or the storage 44 of the data processing system 38 may be any suitable article of manufacture that can store the instructions. For example, the memory 42 and/or the storage 44 may be read-only memory (ROM), randomaccess memory (RAM), flash memory, an optical storage medium, or a hard disk drive, to name a few examples. Additionally, in some embodiments, a display 46, which may be any suitable electronic display, may display images generated by the processor 40, such as alerts and status indicators, and/or to facilitate operator control of the well system 10. The data processing system 38 may be a local component of the well system 10 (e.g., at the surface 24), a part of the well string 12, a remote device that analyzes data received from the surface equipment 30 and/or well string 12, a cloud computing device, or any combination thereof. In some embodiments, the data processing system 38 may be a mobile computing device (e.g., tablet, smart phone, or laptop), a server remote from the well system 10, or a combination thereof.

[0039] As discussed above, well completion and/or other downhole activities may include outfitting the wellbore 16 with a well string 12 of piping 22 and one or more adjustable safety valves 14. The piping 22 may provide a conduit for carrying reservoir fluids from downhole 26 to the surface 24 and/or to allow for pumped fluid from the surface 24 to reach downhole 26. Furthermore, the well string 12 may convey control signals, mechanical linkages (e.g., cables, armatures, etc.), and/or hydraulic lines into the wellbore 16 for controlling aspects of the well string 12, such as one or more adjustable safety valves 14. Adjustable safety valves 14 may be utilized to allow or block (e.g., via the blocking mechanism 20) fluid flow between different portions of the wellbore 16 and/or piping 22, such as to optimize production and/or ease completion of the wellbore 16.

[0040] As discussed herein, the adjustable safety valve 14 may have an adjustable power spring force for use at different depths (e.g., operating pressures of hydraulic pressure) within the wellbore 16. To help illustrate, FIG. 2 is cross-sectional schematic diagram of a ratcheting adjustable safety valve 50 (e.g., adjustable safety valve 14) in an actuated (e.g., open) position and having a blocking mechanism 20 (e.g., flapper) that selectively controls a flow of a fluid 52 (e.g., reservoir fluid such as oil and gas, drilling mud, or etc.) through piping 22. As should be appreciated, the adjustable safety valves 14 (e.g., ratcheting adjustable safety valve 50) discussed herein may be fluidly coupled to the piping 22 and may be considered to include piping 22 therethrough to facilitate the flow of the fluid 52. Additionally, while illustrated and discussed herein as having components that radially surround (e.g., being coaxial or concentric with) an axis 54 through the piping 22, such as for compact execution, as should be appreciated, in some embodiments, the components of the valve system 14 may also be implemented laterally or radially offset from the axis 54 of the piping 22.

[0041] The ratcheting adjustable safety valve 50 may include a flow tube 56 (e.g., annular flow tube) with an axial degree of freedom that articulates the blocking mechanism 20 to an open position when the flow tube 56 is actuated by a piston 58. As should be appreciated, while articulation of the blocking mechanism is described herein as a flow tube 56 pushing a flapper (e g., blocking mechanism 20), other embodiments having different types of blocking mechanisms 20 may be actuated in different manners by the axial movement of the flow tube 56 and/or piston 58. As discussed above, the piston 58 may be motivated by any suitable electrical, mechanical, and/or hydraulic actuation to overcome a power spring force of a power spring 60. The power spring 60 sets a default state (e.g., closed state) of the blocking mechanism 20 by applying a force to the flow tube 56 opposite the direction of the piston 58 articulation. For example, a hydraulic control line of the well string 12 may couple to a hydraulic port 62 of the ratcheting adjustable safety valve 50, and pressurized hydraulic fluid from the hydraulic control line may, in turn, pressurize a piston chamber 64 of the ratcheting adjustable safety valve 50 to actuate the piston 58. As should be appreciated, the piston 58, piston chamber 64, and/or other components of the safety valve 14 described herein as annular may be annular, semi-annular, or disposed at a single radial location, such as corresponding to less than 90 degrees of azimuth. The travel 66 of the piston 58 may correspond to that of the flow tube 56 and, in some embodiments, cause the flow tube 56 to articulate through an opening 68 in the piping 22 that would otherwise be closed off by the blocking mechanism 20 in the default (e.g., closed) state.

[0042] To adjust the force of the power spring 60 (e.g., power spring force) and, therefore, the operating force (e.g., hydraulic pressure force) to open the ratcheting adjustable safety valve 50, an adjustable stop 70 (e.g., annular adjustable stop) of the power spring 60 may be moved. For example, moving the adjustable stop 70 to increase compression of the power spring 60 will increase the potential energy stored therein and the force output thereof, whereas moving the adjustable stop 70 to reduce compression of the power spring 60 will decrease the potential energy stored therein and the force output thereof. The ratcheting adjustable safety valve 50 may include a ratcheting adjustment 72 for moving the adjustable stop 70. For example, the adjustable stop 70 may include a first toothed edge 74 (e.g., toothed annular surface) that engages a toothed ratchet 76 (e.g., annular toothed ratchet) and a second toothed edge 78 (e.g., toothed annular surface) that engages a toothed collet 80 (e.g., annular toothed collet). In some embodiments, the adjustable stop 70 is retained axially between the toothed ratchet 76 and the power spring 60.

[0043] The double ratchet (e.g., first toothed edge 74 and second toothed edge 78) of the adjustable stop 70 allows for the toothed collet 80 to grip and push the adjustable stop 70, increasing the power spring force, while the adjustable stop 70 slides past the toothed ratchet 76 and for the toothed ratchet 76 to hold the adjustable stop 70 in place while the toothed collet 80 slides past the adjustable stop 70, such as to regrip the adjustable stop 70. As such, cycled movement of the toothed collet 80 in axially opposite directions may ratchet the adjustable stop 70 further and further, such as in incremental steps (e.g., uniform distance per step), to increase the power spring force.

[0044] In some embodiments, the toothed collet 80 may be cycled (to adjust the adjustable stop 70) by pressure cycling a hydraulic adjustment port 82 of the ratcheting adjustable safety valve 50. For example, pressurizing the hydraulic adjustment port 82 may motivate an adjustment piston 84 (e.g., annular adjustment piston), overcoming an adjustment spring force of an adjustment spring 86 (e.g., annular adjustment spring), as shown in FIG. 3. The adjustment piston 84 may be coupled to or integral with the toothed collet 80, such that movement of the adjustment piston 84 due to pressurization of the hydraulic adjustment port 82 moves the adjustable stop 70. Additionally, in some embodiments, movement of the adjustment piston may be regulated by an adjustment stop 88 to provide a metered step size 90 (e.g., uniform step distance) for adjustment to the position of the adjustable stop 70. When pressure is removed from the hydraulic adjustment port 82, the adjustment spring 86 may bias the toothed collet 80 and the adjustment piston 84 back to a non-actuated state, as shown in FIG. 4. Moreover, while the toothed collet 80 returns to the non-actuated state, the toothed ratchet 76 maintains the adjustable stop 70 at the moved position, displaced by the step size 90 relative to FIG. 2. As such, pressure cycling the hydraulic adjustment port 82 may correspond to cycling the toothed collet 80 back and forth in the axial direction, translating the adjustable stop 70 with each cycle. Therefore, a desired power spring force may be achieved by pressure cycling the hydraulic adjustment port 82 a corresponding number of times. For example, the power spring force may be increased by a factor of the number of pressure cycles.

[0045] In some embodiments, the ratcheting adjustable safety valve 50 may have unidirectional adjustability. For example, the ratcheting adjustment 72 may operate in a single direction (e.g., to increase the power spring force) without the ability to reduce the power spring force. Moreover, in some embodiments, the power spring force may be reset, such as by disengaging the toothed ratchet 76. Moreover, adjustment of the ratcheting adjustable safety valve 50 may be performed at the surface 24 before implementation downhole 26. Additionally or alternatively, a hydraulic line of the well string 12 may be coupled to the hydraulic adjustment port 82 to adjust the power spring force of the ratcheting adjustable safety valve 50 while downhole 26, allowing for the ratcheting adjustable safety valve 50 to be utilized at a first depth, transferred to a second depth, deeper than the first, and utilized at a new depth after adjusting the power spring force.

[0046] FIG. 5 is a flowchart of an example process 92 for adjusting and utilizing a ratcheting adjustable safety valve 50. In some embodiments, a hydraulic adjustment port 82 may be pressurized to apply a force on an adjustment piston 84, countering an adjustment spring force of an adjustment spring 86 (process block 94). Furthermore, the adjustment piston 84, a toothed collet 80, and an adjustable stop 70 of a power spring 60 may be actuated in response to the force caused by the pressurized hydraulic adjustment port 82 (process block 96). The hydraulic adjustment port 82 may then be depressurized (e g., to atmospheric or otherwise environmental pressure) to return the adjustment piston 84 and the toothed collet 80 to their non-actuated state (process block 98), while the adjustable stop 70 is maintained at the actuated position. It may be determined whether a desired power spring force of the power spring 60 has been achieved (decision block 100) and, if not, the hydraulic adjustment port 82 may be pressurized again (returning to process block 94). If the desired power spring force has been achieved, the ratcheting adjustable safety valve 50 may be implemented downhole 26 (process block 102), such as part of a well string 12. Furthermore, a hydraulic port 62 of the ratcheting adjustable safety valve 50 may be pressurized to apply a force to a piston 58 to counter the power spring force (process block 104), and the piston 58, a flow tube 56, and a blocking mechanism 20 of the ratcheting adjustable safety valve 50 may be actuated to change a state (e.g., open or closed state) of the ratcheting adjustable safety valve 50 (process block 106) in response to the force caused by pressurizing the hydraulic port 62.

[0047] As noted above, in some embodiments, the ratcheting adjustable safety valve 50 may be capable of unidirectional adjustment without providing for a reduction in power spring force before or after increasing the power spring force. As such, in some embodiments, the adjustable safety valve 14 may be a bidirectional adjustable safety valve 110, as shown in FIG. 6. In a similar manner as the ratcheting adjustable safety valve 50, the bidirectional adjustable safety valve 110 may include a blocking mechanism 20 (e.g., flapper) that selectively blocks a flow of fluid 52 through piping 22. Moreover, the blocking mechanism 20 may be articulated by a flow tube 56 that is articulated by a piston 58 (e.g., annular piston) within a piston chamber 64 (e.g., annular piston chamber) that is pressurized via a hydraulic port 62 to motivate the piston 58. However, instead of utilizing a ratcheting adjustment 72, the adjustable stop 70 of the bidirectional adjustable safety valve 110 may be moved by utilizing an adjusting tool inserted into the piping 22 of the bidirectional adjustable safety valve 110.

[0048] The adjustable stop 70 of the bidirectional adjustable safety valve 110 may include (e g., be mechanically coupled to or be integrally formed with) a collet 112 (e.g., annular collet) that is operatively disposed in one of number of grooves 114 (e.g., annular grooves spaced axially apart from one another) corresponding to different adjustable stop positions and, therefore, power spring forces. The collet 112 may be retained in a groove 114 via a collet holder 116, which, in turn, may be biased into position via a retaining spring 118. To change the power spring force, the collet holder 116 may be retracted (e.g., against the force of the retaining spring 118) from the collet 112, and the collet 112 may be moved axially to a different groove 114 in a wall 119 (e.g., annular wall) of the bidirectional adjustable safety valve 110.

[0049] In some embodiments, the collet 112 and collet holder 116 may be disposed between the wall 119 and the flow tube 56. For example, the collet holder 116 may apply radial pressure on the collet 112 and retain the collet 112 in a groove 114. Moreover, the flow tube 56 may provide a barrier to protect the collet 112 and collet holder 116 from the flow of fluid 52 through the piping 22. However, with the flow tube 56 in place, the collet 112 and/or collet holder 116 may be inaccessible. As such, in some embodiments, the flow tube 56 may be a split flow tube assembly have a first tube section 120 integral with, coupled to, or otherwise in contact with the piston 58 and a second tube section 122 disposed proximate the collet 112, collet holder 116, and/or blocking mechanism 20. Furthermore, the first tube section 120 may be coupled to the second tube section 122 of the flow tube 56, such as via threading or other fastening mechanism, such that the first tube section 120 and second tube section 122 may be decoupled (e.g., unscrewed or otherwise unfastened) to allow the second tube section 122 to be relocated, exposing the collet 112 and the collet holder 116. In some embodiments, the second tube section 122 may be temporarily relocated through the blocking mechanism 20 during adjustment of the adjustable stop 70, as shown in FIG. 7.

[0050] To adjust the adjustable stop 70, an adjusting tool 124 may be inserted axially into the piping 22 of the bidirectional adjustable safety valve 110, as shown in FIG. 8. Furthermore, in some embodiments, the adjusting tool 124 may include separately articulatable portions, such as a shaft assembly 126, an inner annular assembly 128, and an outer annular assembly 130. In some embodiments, the outer annular assembly 130 may couple to the bidirectional adjustable safety valve 110, such as via threading 132 or other temporary fastening mechanism. By coupling the adjusting tool 124 to the bidirectional adjustable safety valve 110, the forces of the potential energy of the power spring 60 and/or retaining spring 118 may be retained within the bidirectional adjustable safety valve 110 instead of being transferred to a user (e.g., via the adjusting tool 124).

[0051] In some embodiments, the shaft assembly 126 may include a collet holder engagement assembly 134 and/or a locking engagement assembly 136. The collet holder engagement assembly 134 and/or the locking engagement assembly 136 may be mechanically coupled (e.g., affixed) to a central shaft 138. In some embodiments, the collet holder engagement assembly 134 may include a collet holder dog 140 (e.g., annular dog) that operatively engages (e.g., radially locks) with the collet holder 116. Additionally, in some embodiments, the locking engagement assembly 136 may include a locking dog 142 that operatively engages with the outer annular assembly 130 to hold the central shaft 138 in place when biased by the retaining spring 118, as discussed further below. As should be appreciated, while the collet holder dog 140, locking dog 142, and collet dog (discussed below) are discussed as being singular (e.g., annular, semi-annular, or having an arclength less than 180 degrees) dogs, in some embodiments, the collet holder dog 140, the locking dog 142, and/or collet dog may be implemented by multiple circumferentially spaced dogs.

[0052] To engage the collet holder dog 140, an axial force 144 may be applied to the central shaft 138, as shown in FIG. 9. The axial force 144 may overcome the biasing force of the retaining spring 118 to retract the collet holder 116 from the collet 112, and further translation in the axial direction may engage the locking dog 142, such that the biasing force of the retaining spring 118 is held via the locking dog 142 of the shaft assembly 126 and the outer annular assembly 130. To help further illustrate, FIG. 10 is a partial cross-sectional schematic view of the bidirectional adjustable safety valve 110 with an adjustment tool 124 disposed therein having a collet holder engagement assembly 134 engaging a collet holder 116. In some embodiments, the collet holder engagement assembly 134 may include a dog biasing spring 146A that biases the collet holder dog 140 in the axial direction. When the axial force 144 is applied to move the central shaft 138 to move the central shaft further into the bidirectional adjustable safety valve 110, the collet holder dog 140 may translate in the axial direction and in the radial direction via a ramp 148A (e.g., annular ramp) of the collet holder engagement assembly 134. The radial movement of the collet holder dog 140 may cause the collet holder dog 140 to engage the collet holder 116, and additional axial movement of the central shaft 138, against the retaining spring 118, into the bidirectional adjustable safety valve 110 may retract the collet holder 116 from the collet 112.

[0053] Additionally, in some embodiments, the axial movement of the central shaft 138 may cause the locking dog 142 to translate in the radial direction up a tapered portion 149 of the central shaft 138, such that the locking dog 142 engages a recess 150 of the outer annular assembly 130, as shown in FIG. 11. As the outer annular assembly 130 is coupled to the wall 119 of the bidirectional adjustable safety valve 110 (e g., via threading 132), the biasing force of the retaining spring 118 may be countered (e.g., the collet holder 116 may be held in the retracted position) without maintained force by a user on the central shaft 138.

[0054] With the collet holder 116 retracted, the collet 112 may be moved from one groove 114 to the next to adjust the adjustable stop 70. FIG. 12 is a cross-sectional schematic diagram of the bidirectional adjustable safety valve 110 with an adjustment tool 124 disposed therein and having a collet engagement assembly 151. As the power spring 60 applies force on the adjustable stop 70 and, therefore, the collet 112, it may be desired that a user does not manually directly counter the power spring force. As such, in some embodiments, the inner annular assembly 128 may be threaded to the outer annular assembly 130 and/or the central shaft 138 of the shaft assembly 126. When a relative torque 152 is applied to the inner annular assembly 128, the inner annular assembly 128 may move axially due to threading with the outer annular assembly 130 and/or the central shaft 138. The axial movement of the inner annual assembly may free a collet dog 154 (e.g., annular dog), allowing a dog biasing spring 146B to motivate the collet dog 154 up a ramp 148B (e.g., annular ramp) and engage the adjustable stop 70. In some embodiments, the collet dog 154 may be engaged before the collet holder 116 is retracted, to prevent the collet 112 from escaping the groove 114 before the collet dog 154 engages the adjustable stop 70. Continued applied torque 152, such as in FIG. 13, may continue the axial movement of the inner annular assembly 128 to move the adjustable stop 70.

[0055] When the adjustable stop 70 is in the desired position (e.g., the collet 112 is in the desired groove 114), such as corresponding to the desired power spring force, the collet holder 116 may be released. For example, the central shaft 138 of the shaft assembly 126 may be retracted axially, releasing the locking dog 142 and/or the collet holder dog 140 and allowing the collet holder 116 to translate to the collet 112, motivated by the retaining spring 118. With the collet holder 116 retaining the collet 112 in the desired groove 114, the collet dog 154 may be disengaged by rotating the inner annular assembly 128 in the opposite direction as the previously applied torque 152, and the adjusting tool 124 may be removed from the bidirectional adjustable safety valve 110. Moreover, the second tube section 122 may be recoupled with the first tube section 120, and the bidirectional adjustable safety valve 110 may be utilized downhole 26 with the adjusted (e.g., increased) power spring force. As should be appreciated, a similar process as that discussed above may be utilized when reducing the power spring force. For example, a modified to separate adjusting tool 124 (e.g., with reversed biased collet dog 154) may be utilized to engage the adjustable stop 70 and move the collet 112 to a groove 114 corresponding to a decreased power spring force.

[0056] FIG. 14 is a flowchart of an example process 156 for adjusting the bidirectional adjustable safety valve 110. In some embodiments, a first tube section 120 and second tube section 122 of a flow tube 56 may be decoupled (e.g., unscrewed from one another) to expose a collet 1 12 of an adjustable stop 70 and a collet holder 116 (process block 158). Additionally, an adjusting tool 124 may be inserted into the bidirectional adjustable safety valve 110 (process block 160), for example, via piping 22. In some embodiments, an outer annular assembly 130 of the adjusting tool 124 may be coupled (e.g., threaded) to piping 22 or another component of the bidirectional adjustable safety valve 110, for example, to stabilize the adjustment process. Additionally, an inner annular assembly 128 of the adjusting tool 124 may be rotated (e.g., via an applied torque 152 relative to the outer annular assembly 130) to engage a collet dog 154 of the inner annular assembly 128 with the adjustable stop 70 (process block 162). Additionally, a shaft assembly 126 of the adjusting tool 124 may be translated (e.g., via an axial force 144 into the bidirectional adjustable safety valve 110 to engage a collet holder dog 140 with the collet holder 116, retract the collet holder 116 (e.g., from the collet 112), and engage a locking dog 142 to maintain the collet holder 116 in the retracted position (process block 164), for example, countering the biasing force of a retaining spring 118. The inner annular assembly 128 may be rotated further (e.g., via an applied torque 152) to axially translate the collet dog 154 and the adjustable stop 70, including the collet 112, to a desired position (process block 166). With the adjustable stop 70 at the desired position, the shaft assembly 126 may be translated out of the bidirectional adjustable safety valve 110 to disengage the locking dog 142 and collet holder dog 140, releasing the collet holder 116 (process block 168), for example to engage and retain the collet 112 at the desired position (e.g., within a groove 114). Additionally, the inner annular assembly 128 may be counter-rotated (e.g., rotated in the opposite direction as the previously applied torque 152) to disengage the collet dog 154 from the adjustable stop 70 (process block 170). Furthermore, the adjusting tool 124 may be removed from the bidirectional adjustable safety valve 110, and the first tube section may be recoupled with the second tube section 122 (process block 172), for example, to restore operability to the bidirectional adjustable safety valve 110 at the new power spring force.

[0057] Technical effects of the present disclosure allow for a single adjustable safety valve 14 to be reconfigured for use at different depths and/or operating pressures (e.g., hydraulic pressures) within a wellbore 16. Such adjustability may provide increased flexibility, consolidation of parts, and increased efficiency in time, cost, and/or labor at a well site. As should be appreciated, although the flowcharts of FIGS. 5 and 14 are shown in a given order, in certain embodiments, portions of the flowcharts may be reordered, deleted, occur simultaneously, and/or be initiated/controlled by one or multiple data processing systems 38.

[0058] The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

[0059] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function], ..” or “step for [performing [a function], . it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

Claims

1. A safety valve of a well string, the safety valve comprising: a fluid conduit disposed about an axis and configured to convey a fluid through the safety valve; a valve closure member configured to articulate between a first state and a second state to selectively block a flow of the fluid through the fluid conduit; a power spring configured to bias the valve closure member toward the first state via a power spring force of the power spring; a piston configured to operatively overcome the power spring force to articulate the valve closure member toward the second state; and an adjustable stop configured to be disposed at one of a plurality of positions within the safety valve, wherein the power spring is compressed between the piston and the adjustable stop, and wherein different positions of the plurality of positions correspond to different amounts of the power spring force.

2. The safety valve of claim 1, wherein the different positions of the adjustable stop correspond to different depths of operation of the safety valve within a wellbore.

3. The safety valve of claim 1 , wherein the adjustable stop comprises an annular adjustable stop disposed circumferentially about the axis, wherein the power spring is disposed circumferentially about the axis, and wherein the piston is configured to articulate axially relative to the axis in response to overcoming the power spring force.

4. The safety valve of claim 1, wherein the first state comprises a closed state and the second state comprises an open state.

5. The safety valve of claim 4, comprising an annular flow tube disposed between the piston and the valve closure member and configured to contact and articulate the valve closure member in response to articulation of the piston.

6. The safety valve of claim 5, wherein the annular flow tube comprises a split flow tube assembly comprising a first tube section coupled to the piston and a second tube section removably coupled to the first tube section.

7. The safety valve of claim 6, wherein removal of the second tube section from the first tube section exposes the adjustable stop for adjustment between the plurality of positions.

8. The safety valve of claim 7, wherein the adjustable stop is configured to articulate axially in response to an axial movement of a collet dog of an adjusting tool operatively disposed within the fluid conduit.

9. The safety valve of claim 1, wherein the adjustable stop comprises a first toothed surface configured to contact a ratchet and a second toothed surface configured to contact a toothed collet.

10. The safety valve of claim 9, wherein an axial movement of the toothed collet in a first direction is configured to articulate the adjustable stop in the first direction from a first position of the plurality of positions to a second position of the plurality of positions, and wherein the adjustable stop is maintained at the second position via the ratchet in response to a subsequent axial movement of the toothed collet in a second direction opposite the first direction.

11. The safety valve of claim 10, wherein the axial movement of the toothed collet is motivated by pressurization of a hydraulic adjustment port of the safety valve, wherein a distance of the axial movement is preset by an adjustment limiter to regulate a step-size between the different positions of the plurality of positions.

12. The safety valve of claim 1, wherein the valve closure member comprises a flapper valve.

13. A method comprising: adjusting a position of an annular adjustable stop of a power spring of a safety valve in an axial direction relative to an axis, wherein the annular adjustable stop is disposed circumferentially about the axis, the power spring is disposed between an actuatable piston and the adjustable stop, and the position corresponds to a biasing force of the power spring to maintain the safety valve in a closed position; conveying the safety valve into a wellbore at a depth corresponding to the biasing force; and applying a hydraulic pressure to a piston chamber comprising the actuatable piston such that a hydraulic force on the piston is greater than biasing force to facilitate transitioning the safety valve from the closed state to an open state.

14. The method of claim 13, wherein adjusting the position of the annular adjustable stop comprises cyclically applying a plurality of hydraulic pulses to a hydraulic adjustment port of the safety valve to cyclically motivate an adjustment piston to articulate the adjustable stop.

15. The method of claim 14, wherein a number of the plurality of hydraulic pulses corresponds to a displacement of the position of the annular adjustable stop and the biasing force.

16. The method of claim 13, wherein adjusting the position of the annular adjustable stop comprises: retracting a collet holder configured to maintain a collet of the adjustable stop in the position; moving the collet from a first location within the safety valve to a second location within the safety valve; and releasing the collet holder such that the collet holder maintains the collet at the second location.

17. A safety valve adjusting tool comprising: an outer annular assembly configured to mechanically couple to a safety valve; and a collet engagement assembly configured to be axially inserted into the safety valve and comprising a collet dog configured to selectively engage a collet of an adjustable stop of the safety valve, wherein an axial position of the adjustable stop within the safety valve corresponds to an amount of a power spring force that biases a valve closure member to a closed state, wherein the collet dog is axially adjustable relative to the outer annular assembly such that an axial movement of the collet dog, relative to the outer annular assembly, operatively changes the axial position of the adjustable stop within the safety valve.

18. The safety valve adjusting tool of claim 17, comprising: a collet holder engagement assembly comprising a collet holder dog configured to selectively engage a collet holder of the safety valve, wherein the collet holder is configured to operatively secure the axial position of the adjustable stop, wherein the collet holder dog is axially adjustable relative to the outer annular assembly such that movement of the collet holder dog in a first axial direction operatively disengages the collet holder of the safety valve from the collet of the safety valve.

19. The safety valve adjusting tool of claim 18, comprising a locking assembly configured to selectively block movement of the collet holder dog in a second axial direction, opposite the first axial direction, relative to the outer annular assembly.

20. The safety valve adjusting tool of claim 17, comprising an inner annular assembly coupled to the collet engagement assembly, wherein the inner annular assembly is coupled to the outer annular assembly such that a rotational movement of the inner annular assembly relative to the outer annular assembly causes the axial movement of the collet dog.