CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present document is based on and claims priority to U.S. Provisional Patent Application No. 63/198,624, filed October 30, 2020, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, 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 admissions of prior art.

[0003] A blowout preventer (BOP) is installed on a wellhead to seal and control an oil and gas well during various operations. For example, during drilling operations, a drill string may be suspended from a rig through the BOP into a wellbore. A drilling fluid is delivered through the drill string and returned up through an annulus between the drill string and a casing that lines the wellbore. In the event of a rapid invasion of formation fluid in the annulus, commonly known as a “kick,” the BOP may be actuated to seal the annulus and to control fluid pressure in the wellbore, thereby protecting well equipment positioned above the BOP.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Various features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying figures in which like characters represent like parts throughout the figures, wherein: [0005] FIG. 1 is a block diagram of a mineral extraction system, in accordance with an embodiment of the present disclosure;

[0006] FIG. 2 is a cross-sectional top view of a portion of a blowout preventer (BOP) that may be used in the mineral extraction system of FIG. 1 , in accordance with an embodiment of the present disclosure;

[0007] FIG. 3 is a perspective front view of a bi-directional ram that may be used in the BOP of FIG. 2, in accordance with an embodiment of the present disclosure;

[0008] FIG. 4 is a cross-sectional side view of the bi-directional ram of FIG. 3, wherein a flow path through the bi-directional ram is closed to block fluid flow, in accordance with an embodiment of the present disclosure;

[0009] FIG. 5 is a cross-sectional side view of the bi-directional ram of FIG. 3, wherein the flow path through the bi-directional ram is open to enable fluid flow, in accordance with an embodiment of the present disclosure;

[0010] FIG. 6 is a schematic side view of a portion of the BOP of FIG. 1 having the bi-directional ram of FIG. 3 with high pressure above the BOP, in accordance with an embodiment of the present disclosure;

[0011] FIG. 7 is a schematic side view of a portion of the BOP of FIG. 1 having the bi-directional ram of FIG. 3 with high pressure below the BOP, in accordance with an embodiment of the present disclosure; and

[0012] FIG. 8 is a schematic side view of a portion of the BOP of FIG. 1 having the bi-directional ram of FIG. 3 as the BOP is adjusted from a closed configuration to an open configuration, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0013] One or more specific embodiments of the present disclosure will be described below. These described embodiments are only exemplary of the present disclosure. Additionally, in an effort to provide a concise description of these exemplary embodiments, all 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 must 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 nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0014] The present embodiments are generally directed to a bi-directional ram for a blowout preventer (BOP). When installed within the BOP, the bi-directional ram may be configured to adjust between an open configuration (e.g., retracted configuration) and a closed configuration (e.g., extended configuration). In the open configuration, the bi-directional ram may enable a fluid flow through a central bore of the BOP. In the closed configuration, the bi-directional ram may block the fluid flow through the central bore of the BOP. The bi-directional ram may include features (e.g., sealing elements, flow paths, and valves) that enable the bi-directional ram to effectively seal high pressure above the bi-directional ram (e.g., during component testing) and to effectively seal high pressure below the bi-directional ram (e.g., during blowout conditions within a wellbore).

[0015] Because the bi-directional ram is capable of effectively sealing in both directions (e.g., above and below the bi-directional ram), the bi-directional ram may enable a reduction in a number of cavities used in a BOP stack, which may enable a reduction in a size (e.g., height) of the BOP stack. For example, some existing rams for BOPs may only seal in one direction (e.g., block pressure from above the rams or block pressure from below the rams, but not both). Thus, some existing BOP stacks may include a first cavity that houses a first ram that operates to block pressure from above the first ram and a second cavity (e.g., stacked vertically with respect to the first cavity) that houses a second ram that operates to block pressure from below the second ram. The bi-directional ram disclosed herein may also provide other advantages, such as simplified operation of the BOP stack and cost savings.

[0016] While the disclosed embodiments are described in the context of a drilling system and drilling operations to facilitate discussion, it should be appreciated that the bi-directional ram may be adapted for use in other contexts and during other operations. For example, the bi-directional ram may be used in a pressure control equipment (PCE) stack that is coupled to and/or positioned vertically above a wellhead during various intervention operations (e.g., inspection or service operations), such as wireline operations in which a tool supported on a wireline is lowered through the PCE stack to enable inspection and/or maintenance of a well. In the present disclosure, a conduit may be any of a variety of tubular or cylindrical structures, such as a drill string, a wireline, a Streamline™, a slickline, a coiled tubing, or other spoolable rod.

[0017] With the foregoing in mind, FIG. 1 is a block diagram of an embodiment of a mineral extraction system 10. The mineral extraction system 10 may be configured to extract various minerals and natural resources, including hydrocarbons (e.g., oil and/or natural gas), from the earth and/or to inject substances into the earth. The mineral extraction system 10 may be a land-based system (e.g., a surface system) or an offshore system (e.g., an offshore platform system).

[0018] As shown, a BOP stack 12 may be mounted to a wellhead 14, which is coupled to a mineral deposit 16 via a wellbore 18. The wellhead 14 may include or be coupled to any of a variety of other components such as a spool, a hanger, and a “Christmas” tree. The wellhead 14 may return drilling fluid or mud toward a surface during drilling operations, for example. Downhole operations are carried out by a conduit 20 (e.g., drill string) that extends through a central bore 22 of the BOP stack 12, through the wellhead 14, and into the wellbore 18.

[0019] As discussed in more detail below, the BOP stack 12 may include one or more BOPs 24 (e.g., ram BOPs) that each support a bi-directional ram that is configured to seal high pressure above the bi-directional ram in the central bore 22 and to seal high pressure below the bi-directional ram in the central bore 22. To facilitate discussion, the BOP stack 12 and its components may be described with reference to a vertical axis or direction 30, an axial axis or direction 32, and/or a lateral axis or direction 34.

[0020] FIG. 2 is a cross-sectional top view of a portion of an embodiment of the BOP 24 that may be used in the mineral extraction system 10 of FIG. 1 , in accordance with an embodiment of the present disclosure. As shown, the BOP 24 includes opposed bi-directional rams 50 that are positioned such that the BOP 24 is in an open configuration 54. In the open configuration 54, the opposed bidirectional rams 50 are withdrawn from the central bore 22, do not contact the conduit 20, and/or do not contact one another.

[0021] As shown, the BOP 24 includes a housing 56 surrounding the central bore 22. The housing 56 is generally rectangular in the illustrated embodiment, although the housing 56 may have any cross-sectional shape, including any polygonal shape and/or annular shape. The housing 56 defines a cavity 58 that supports the opposed bi-directional rams 50. Bonnet assemblies 60 are mounted on opposite sides of the housing 56 (e.g., via threaded fasteners). Each bonnet assembly 60 supports an actuator 62, which may include a piston 64 and a connecting rod 66. The actuators 62 may drive the opposed bidirectional rams 50 toward and away from one another along the axial axis 32 to transition the BOP 24 between the open configuration and a closed configuration. In the closed configuration, the opposed bi-directional rams 50 are positioned within the central bore 22, contact and/or shear the conduit 20 to seal the central bore 22, and/or contact one another to seal the central bore 22.

[0022] Each of the opposed bi-directional rams 50 may include a body 68 (e.g., bi-directional ram body) that includes a forward surface 70 (e.g., side; portion; wall) and a rearward surface 72 (e.g., side; portion; wall). The forward surfaces 70 may be positioned proximate to the central bore 22 and may face one another when the opposed bi-directional rams 50 are installed within the housing 56. The rearward surfaces 72 may be positioned distal from the central bore 22 and proximate to a respective one of the actuators 62 when the opposed bi-directional rams 50 are installed within the housing 56. The forward surfaces 70 may be configured to couple to and/or support sealing elements 76 (e.g., elastomer elements) that are configured to form a seal to seal the central bore 22 while the BOP 24 is in the closed configuration. As discussed in more detail below, for each of the opposed bi-directional rams 50, the sealing elements 76 may extend along laterally-outer surfaces and also wrap around the body 68 so as to form an annular sealing element that enables each of the opposed bidirectional rams 50 to seal in both directions (e.g., to seal high pressure above the opposed bi-directional rams 50 in the central bore 22 and to seal high pressure below the opposed bi-directional rams 50 in the central bore 22). The rearward surfaces 72 may include an attachment recess 74 (e.g., interface) that is configured to engage with the connecting rod 66 of the actuator 62. In FIG. 2, the forward surfaces 70 include the sealing elements 76 that have a generally straight sealing edge to seal against one another to facilitate discussion; however, it should be appreciated that the forward surfaces 70 of the opposed bidirectional rams 50 may have any of a variety of shapes or features (e.g., curved portions to seal against the conduit 20; knife edges to shear the conduit 20).

[0023] FIG. 3 is a perspective front view of an embodiment of one of the opposed bi-directional rams 50 that may be used in the BOP. As shown, the bidirectional ram 50 includes the body 68 having the forward surface 70 and the rearward surface 72. The bi-directional ram 50 in FIG. 3 is a blind ram that is configured to seal against an opposed bi-directional ram to seal the central bore of the BOP. The bi-directional ram 50 also includes a seal groove 78 that is formed in the forward surface 70 and that extends along the lateral axis 34 of the bi-directional ram 50. The seal groove 78 is configured to receive and to support the sealing element. Although not shown for image clarity, the bi-directional ram 50 may include additional seal grooves (e.g., circumferentially about the bidirectional ram 50; formed in a radially-outer surface of the bi-directional ram 50) to support the sealing element to form the annular seal about the body 68 of the bi-directional ram 50. [0024] Furthermore, the bi-directional ram 50 in FIG. 3 has a generally cylindrical shape with a circular cross-section, as well as leading protrusions 80 that are configured to engage corresponding leading protrusions on the opposed bi-directional ram. However, it should be appreciated that the bi-directional ram 50 may have any of a variety of other configurations. For example, the bidirectional ram 50 may be a pipe ram that includes a curved portion in the forward surface 70 and that extends along the lateral axis 34 of the bi-directional ram 50 to seal about the conduit 20, or the bi-directional ram 50 may be a shear ram that includes a knife edge that is formed on the forward surface 70 and that extends along the lateral axis 34 of the bi-directional ram 50. Additionally or alternatively, the bi-directional ram 50 may have a generally cuboid shape with a rectangular cross-section or any other suitable shape.

[0025] The bi-directional ram 50 includes a pressure-assist system 82 (e.g., bi-directional sealing system) that, under certain conditions, enables fluid flow (e.g., pressure) from the central bore of the BOP to a space within the cavity behind the bi-directional ram 50. The fluid may then exert a force on the rearward surface 72 of the bi-directional ram 50 to drive the bi-directional ram 50 toward the opposed bi-directional ram 50 to assist in maintaining the closed configuration and sealing the central bore of the BOP. As shown, the pressureassist system 82 includes a first flow path 84 (e.g., through-hole) that extends from an upper portion of the forward surface 70 (e.g., above the seal groove 78 along the vertical axis 30) to or toward the rearward surface 72 and a second flow path 86 (e.g., through-hole) that extends from a lower portion of the forward surface 70 (e.g., below the seal groove 78 along the vertical axis 30) to or toward the rearward surface 72.

[0026] A first valve 88 (e.g., check valve or one-way valve) is provided to adjust the fluid flow through the first flow path 84, and a second valve 90 (e.g., check valve or one-way valve) is provided to adjust the fluid flow through the second flow path 86. The first valve 88 includes a first valve member 92 and a first biasing member 94 (e.g., spring), and the second valve 90 includes a second valve member 96 and a second biasing member 98 (e.g., spring). The first biasing member 94 may drive the first valve member 92 toward the forward surface 70 and toward a respective closed position that blocks the fluid flow through the first flow path 84. Similarly, the second biasing member 98 may drive the second valve member 96 toward the forward surface 70 and toward a respective closed position that blocks the fluid flow through the second flow path 86. For example, in the respective closed position, the first valve member 92 may seal against a surface (e.g., radially-inner surface) of the first flow path 84 to thereby block the fluid flow through the first flow path 84. Similarly, in the respective closed position, the second valve member 96 may seal against a surface (e.g., radially-inner surface) of the second flow path 86 to thereby block the fluid flow through the second flow path 86.

[0027] In an operation to seal high pressure above the bi-directional ram 50 (e.g., on a first side of the bi-directional ram 50; above the seal groove 78 along the vertical axis 30), the bi-directional ram 50 may be driven from the open configuration to the closed configuration via the connecting rod 66 until the bidirectional ram 50 seals against the opposed bi-directional ram. The high pressure above the bi-directional ram 50 may then exert a force on the first valve member 92 of the first valve 88 that overcomes a biasing force applied by the first biasing member 94 to drive the first valve member 92 of the first valve 88 toward the rearward surface 72. The first valve member 92 may unseal from the surface of the first flow path 84 to thereby enable the fluid flow from the central bore of the BOP to the space within the cavity behind the bi-directional ram 50, which may then drive the bi-directional ram 50 toward the closed configuration to assist in maintaining the bi-directional ram 50 in the closed configuration.

[0028] In an operation to seal high pressure below the bi-directional ram 50 (e.g., on a second side of the bi-directional ram 50; below the seal groove 78 along the vertical axis 30), the bi-directional ram 50 may be driven from the open configuration to the closed configuration via the connecting rod 66 until the bidirectional ram 50 seals against the opposed bi-directional ram. The high pressure below the bi-directional ram 50 may then exert a force on the second valve member 96 of the second valve 90 that overcomes a biasing force applied by the second biasing member 98 to drive the second valve member 96 of the second valve 90 toward the rearward surface 72. The second valve member 96 may unseal from the surface of the second flow path 86 to thereby enable the fluid flow from the central bore of the BOP to the space within the cavity behind the bi-directional ram 50, which may then drive the bi-directional ram 50 toward the closed configuration to assist maintaining the bi-directional ram 50 in the closed configuration.

[0029] To enable the transition of the bi-directional ram 50 from the closed configuration to the open configuration, the pressure-assist system 82 may include a linkage member 100 that is configured to adjust the second valve 90 to the open position. For example, the linkage member 100 may be coupled to the second valve member 96 of the second valve 90 and to the connecting rod 66. Thus, movement of the connecting rod 66 away from the central bore of the BOP to retract the bi-directional ram 50 also drives the second valve member 96 of the connecting rod 66 to the open position. The pressure in the space within the cavity behind the bi-directional ram 50 may then flow through the second flow path 86 to the central bore of the BOP, which then enables the connecting rod 66 to retract the bi-directional ram 50 out of the central bore of the BOP to the open configuration. While the linkage member 100 is shown as coupled to the second valve member 96 of the second valve 90 to facilitate discussion, it should be appreciated that the linkage member 100 may be coupled to the first valve member 92 of the first valve 88.

[0030] FIG. 4 is a cross-sectional side view of the bi-directional ram 50, wherein the second flow path 86 through the bi-directional ram 50 is closed to block fluid flow, in accordance with an embodiment of the present disclosure. FIG. 5 is a cross-sectional side view of the bi-directional ram of FIG. 3, wherein the second flow path 86 through the bi-directional ram 50 is open to enable the fluid flow, in accordance with an embodiment of the present disclosure. As shown, the second flow path 86 extends from the forward surface 70 toward the rearward surface 72. The second valve 90 that includes the second valve member 96 and the second biasing member 98 is positioned to adjust between the closed position of FIG. 4 and the open position of FIG. 5.

[0031] With reference to FIG. 4, while the bi-directional ram 50 is driven to seal against the opposed bi-directional ram (e.g., the BOP is in the closed configuration), the connecting rod 66 may be in an extended position in which a portion of the connecting rod 66 contacts a first surface (e.g., forward surface) of the attachment recess 74. Additionally, the second valve 90 may be in the closed position while the pressure in the space within the cavity behind the bidirectional ram 50 is greater than the pressure within the central bore below the bi-directional ram 50.

[0032] With reference to FIG. 5, while the bi-directional ram 50 is driven away from the opposed bi-directional ram (e.g., the BOP is adjusted to the open configuration), the connecting rod 66 may be in a retracted position in which the portion of the connecting rod 66 contacts a second surface (e.g., rearward surface) of the attachment recess 74. Additionally, the linkage member 100 may drive the second valve 90 to the open position as the connecting rod 66 moves toward the retracted position to thereby enable the pressure in the space within the cavity behind the bi-directional ram 50 to pass into the central bore 22. This venting of the pressure in the space within the cavity behind the bi-directional ram 50 may facilitate transition of the BOP to the open configuration.

[0033] FIG. 6 is a schematic side view of a portion of the BOP 24 having the bi-directional ram 50 with high pressure above the BOP 24, in accordance with an embodiment of the present disclosure. FIG. 7 is a schematic side view of a portion of the BOP 24 having the bi-directional ram 50 with high pressure below the BOP 24, in accordance with an embodiment of the present disclosure. FIG. 8 is a schematic side view of a portion of the BOP 24 having the bi-directional ram 50 as the BOP 24 is adjusted from the closed configuration to the open configuration, in accordance with an embodiment of the present disclosure.

[0034] As shown, the bi-directional ram 50 includes the sealing element 76 that extends across the forward surface 70 of the bi-directional ram 50 and also circumferentially surrounds the bi-directional ram 50. The sealing element 76 is configured to seal against the opposing bi-directional ram and/or the conduit 20 within the central bore of the BOP 24, as well as to seal against the cavity 58 to enable the bi-directional ram 50 to block the fluid flow through the central bore of the BOP 24.

[0035] With reference to FIG. 6, with the high pressure above the BOP 24 while the BOP 24 is in the closed configuration, the high pressure may flow through the first flow path 84 to the space within the cavity 58 behind the bidirectional ram 50. With reference to FIG. 7, with the high pressure below the BOP 24 while the BOP 24 is in the closed configuration, the high pressure may flow through the second flow path 86 to the space within the cavity 58 behind the bi-directional ram 50. With reference to FIG. 8, when the connecting rod 66 is retracted to drive the BOP 24 to the open configuration, the second flow path 86 may open to release the high pressure in the space within the cavity 58 behind the bi-directional ram 50 to the central bore of the BOP (e.g., via the linkage member opening the second valve for the second flow path 86).

[0036] It should be appreciated that various configurations are envisioned. For example, the first flow path 84 and/or the second flow path 86 may terminate at a radially-outer surface (e.g., top surface, bottom surface, side surface) of the bi-directional ram 50 (e.g., instead of at the forward surface) to thereby more easily expose one end of the first flow path 84 and/or the second flow path 86 to the central bore of the BOP even while the BOP 24 is in the closed configuration.

[0037] While the disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the following appended claims. Furthermore, numerical terms, such as “first,” “second,” and “third” are used to distinguish components to facilitate discussion, and it should be appreciated that the numerical terms may be used differently or assigned to different elements in the claims.