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.
A blowout preventer (BOP) stack may be installed on a wellhead to seal and control an oil and gas well during drilling operations. A tubular string may be suspended inside a drilling riser and extend through the BOP stack into the wellhead. During drilling operations, a drilling fluid may be delivered through the tubular string and returned through a bore between the tubular string and a casing of the drilling riser. In the event of a rapid invasion of formation fluid in the bore, commonly known as a “kick,” the BOP stack may be actuated to isloate the drilling riser from the wellhead and to control a fluid pressure in the bore, thereby protecting well equipment disposed above the BOP stack.
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:
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.
When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” 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. Moreover, the use of “top,” “bottom,” “above,” “below,” and variations of these terms is made for convenience, but does not require any particular orientation of the components.
Embodiments of the present disclosure relate to a blowout preventer (“BOP”) system that may include an improved side packer assembly having an increased amount of resilient material to enhance a seal formed by the BOP. A BOP may be included at a wellhead to block a fluid from inadvertently flowing from the wellhead to a drilling platform (e.g., through a drilling riser). For example, pressures may fluctuate within a natural reservoir, which may lead to a surge in fluid flow from the wellhead toward the drilling platform when the pressure reaches a threshold value. To block fluid from flowing toward the drilling platform during a kick and/or a blowout condition, the BOP may be actuated to cover a bore in the BOP that couples the wellhead to the drilling riser. In some cases, rams of the BOP are actuated to engage (e.g., contact and/or cut) a tubular disposed in the bore.
BOP rams may include packer assemblies that are configured to engage a surface of the bore when the BOP rams are actuated to seal the bore and further block a flow of fluid from flowing from the wellhead to the drilling riser. Some packer assemblies are secured to a BOP ram using a fastener, such as a pin, a bolt, a screw, or another suitable fastener. The fastener limits movement of the packer assembly as the BOP ram is actuated to seal the bore. Further, the fastener maintains a connection between the packer assembly and the BOP ram when the BOP ram is retracted to unblock the bore. Unfortunately, machining the BOP ram and the packer assembly to receive the fastener is a precise process that has limited tolerance. As such, machining the BOP ram and packer assembly is complex, time consuming, and expensive. Additionally, the fastener extends into a resilient material of the packer assembly, thereby reducing an amount of resilient material that may be used to form the seal. Additionally, the reduced resilient material may decrease a compressibility of the packer assembly and unevenly distribute forces applied to the packer assembly because of asymmetry caused by the fastener extending through the resilient material. Accordingly, the fastener may reduce a lifespan of the packer assembly and lead to relatively frequent replacement and/or maintenance of the BOP, for example.
In accordance with embodiments of the present disclosure, a packer assembly (e.g., a side packer assembly) of a BOP ram may be coupled to the BOP ram using a key and slot configuration (e.g., interface). For example, a receptacle of the BOP ram may include a protrusion (e.g., a key) that is configured to be disposed in a slot of the packer assembly, or vice versa. In some embodiments, the packer assembly may be configured to move within the receptacle because the protrusion may slide within the slot. Further, a length of the slot may be configured to block movement of the packer assembly and maintain the packer assembly within the receptacle. For example, the protrusion eventually contacts or reaches an end of the slot, and thus, blocks further movement of the packer assembly with respect to the BOP ram. As such, a connection between the packer assembly and the BOP ram is maintained when the BOP ram is moved toward a retracted position to open the bore through the BOP, for example. Additionally, in some embodiments, at least a portion the packer assembly includes a surface having a curvature to facilitate installation of the packer assembly into the receptacle of the BOP ram. The curved surface of the packer assembly may also be configured to retain the packer assembly within the receptacle.
With the foregoing in mind,
To facilitate discussion, the BOP stack assembly 16 and its components may be described with reference to an axial axis or direction 30, a second axis or direction 32 extending longitudinally along a centerline 33 of the BOP stack assembly 16 (e.g., a longitudinal axis crosswise to the axial axis or direction 30), and a third axis or direction 34 (e.g., a lateral axis crosswise to the axial axis or direction 30 and the second axis or direction 32). As shown, the BOP stack assembly 16 includes a BOP stack 38 having multiple BOPs 40 (e.g., ram BOPs) axially stacked (e.g., along the axial axis 30) relative to one another. As discussed in more detail below, each BOP 40 may include a pair of longitudinally opposed rams and corresponding actuators 42 that actuate and drive the rams toward and away from one another along the second axis 32. Although four BOPs 40 are shown, the BOP stack 38 may include any suitable number of the BOPs 40 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more BOPs 40). Additionally, the BOP stack 38 may include any of a variety of different types of rams. For example, in certain embodiments, the BOP stack 38 may include one or more BOPs 40 having opposed shear rams or blades configured to sever the tubular string 24 and seal off the wellbore 26 from the riser 22 and/or one or more BOPs 40 having opposed pipe rams configured to engage the tubular string 24 and to seal the bore 25 (e.g., an annulus around the tubular string 24).
The first and second rams 50, 52 may each include one or more packer assemblies 66 (e.g., side packer assemblies) that are configured to engage a surface 67 (e.g., annular surface) of the bore 25 to enhance a seal formed by the BOP 40. For example, as shown in the illustrated embodiment of
As discussed above, the packer assemblies 66 may be coupled to the first and second rams 50, 52 via a key-slot interface 69. For example, the packer assemblies 66 may include a slot that may receive a protrusion formed in a receptacle of the first and second rams 50, 52. In other embodiments, the packer assemblies 66 include the protrusion which is disposed in a corresponding slot formed in the receptacle of the first and second rams 50, 52. Accordingly, such a configuration may facilitate manufacture and installation of the packer assemblies 66. For example,
As shown in the illustrated embodiment of
The first structural support 126 may be coupled to the first insert 122 and/or the packing element 120, and the second structural support 128 may be coupled to the second insert 124 and/or the packing element 120 using one or more fasteners 134 (e.g., pins) disposed within corresponding openings 136 within the first insert 122 and the second insert 124. The first insert 122 and the second insert 124 may facilitate insertion of the packer assembly 68 into the receptacle 100 of the ram 50. For example, a first rounded corner 129 of the first insert 122 and a second rounded corner 131 of the second insert 124 may enable the packer assembly 68 to snap into the receptacle 100. Further, the first insert 122 and the second insert 124 may secure the packer assembly 68 in the receptacle 100. As discussed in detail below with reference to
Further still, the first structural support 126, the second structural support 128, the first member 130, and/or the second member 132 enable the packing element 120 of the packer assembly 68 to compress longitudinally, while maintaining substantially the same structure of the packer assembly 68 upon compression (e.g., the first structural support 126, the second structural support 128, the first member 130, and/or the second member 132 are substantially rigid). In some embodiments, the first member 130 and the second member 132 may remain substantially stationary relative to the ram 50 as the packing element 120 of the packer assembly 68 is compressed longitudinally due to contact with the corresponding packer assembly 66 of the second ram 52. In some embodiments, the first member 130 includes a protrusion 135 that is disposed into a corresponding groove 137 (see, e.g.,
Further, a wall 139 (see, e.g.,
In some embodiments, the packing member 120, the first insert 122, the second insert 124, the first structural support 126, the second structural support 128, the first member 130, and/or the second member 132 may be coupled to one another to form a single-packaged unit that maintains a structural shape substantially similar to a cross-sectional shape of the receptacle 100. As such, the packer assembly 68 may be disposed in the receptacle 100 by snapping each of the components of the packer assembly 68 into the receptacle 100 substantially simultaneously.
As discussed above, the packer assembly 68 may not include a fastener (e.g., threaded fastener) to secure the packer assembly 68 to the ram 50. Instead, the packer assembly 68 may be secured to the ram 50 via the rounded surface 136 and/or a key and slot interface between the packer assembly 68 and the ram 50. For example,
For instance,
Further, the protrusion 160 and the slot 180 may retain the packer assembly 68 within the receptacle 100 as the ram 50 is retracted to the default position 54 and as the packing element 120 decompresses. For example, as the ram 50 is directed away from the bore 25 along the second axis 32, the packer assembly 68 may remain substantially stationary with respect to the bore 25 along the second axis 32. Therefore, the ram 50 moves independent of the packer assembly 68. As such, the protrusion 160 moves within the slot 180 until the protrusion 160 contacts an end 185 (e.g., a second end), which blocks movement of the ram 50 independent of the packer assembly 68. The packer assembly 68 may then move with the ram 50 away from the bore 25, and thus, remain within the receptacle 100 of the ram 50. The protrusion 160 and the slot 180 therefore enable a predetermined amount of compression of the packing element 120 when the first ram 50 is actuated toward the bore 25 and the second ram 52 to seal the bore 25 and retains the packer assembly 68 within the receptacle 100 when the first ram 50 is actuated away from the bore 25 and the second ram 52. Moreover, due to the configuration of the packer assembly 68 and/or because the packer assembly 68 is not coupled to the ram 50 using a fastener, the packing element 120 may include an increased amount of resilient material, which may enable increased contact between the surface 67 of the bore 25 and the packer assembly 68, thereby enhancing a seal of the bore 25.
As shown in the illustrated embodiment of
Further, the slot 180 forms a substantially curved or elliptical shape that is configured to conform to a shape of the protrusion 160. As such, a shape of the slot 180 may be determined at least partially by the shape of the protrusion 160 to facilitate movement of the protrusion 160 within the slot 180. In any case, the protrusion 160 and the slot 180 are configured to retain the packer assembly 68 within the receptacle 100 as the packing element 120 undergoes compression and decompression.
Further, a profile of the packer assembly 68 (e.g., the first insert 122) may secure the packer assembly 68 in the receptacle 100. In other words, the profile of the packer assembly 68 blocks movement of the packer assembly 68 away from the ram 50 along the third axis 34. For example,
When the controller 46 determines that the bore 25 should be sealed (e.g., the wellbore 26 is experiencing blowout conditions), the controller 46 may send one or more signals to actuate the BOP 40, as shown at block 254. As discussed above, the BOP 40 includes the first and second rams 50 and 52, which may each include one or more packer assemblies 66 coupled to the first and second rams 50 and 52 via respective key-slot interfaces 69. Each of the packer assemblies 66 include the first insert 122 and/or the second insert 124, which may include the slot 180. When the packer assemblies 66 are disposed in respective receptacles 100 of the rams 50, 52, the slot 180 may engage the protrusion 160 positioned on the surface 162 of the receptacle 100, for example.
In any case, at block 256, the first and second rams 50 and 52 are moved toward one another such that the first packer assembly 68 engages the third packer assembly 72 and/or the second packer assembly 70 engages the fourth packer assembly 74. The packer assemblies 66 may then compress, such that the packing element 120 is compressed longitudinally and expanded laterally outward from the receptacle 100 toward the surface 67 of the bore 25 to form a seal between the rams 50 and 52 and the surface 67. As such, fluid may be substantially blocked from flowing from the wellbore 26 to the platform 12. As noted above, the protrusion 160 may be configured to move within the slot 180 as the packer assemblies 66 are compressed (e.g., when corresponding packer assemblies 66 on the first ram 50 and the second ram 52 engage one another). Further, the protrusion 160 may engage the end 185 of the slot to retain the packer assemblies 66 within the respective receptacles 100 when the rams 50, 52 are retracted and/or directed away from one another with respect to the bore 25.
While the present 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 present disclosure is not intended to be limited to the particular forms disclosed. Rather, the present disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the following appended claims.
This application is a continuation of U.S. application Ser. No. 17/321,659, which was filed May 17, 2021, which is a continuation of U.S. application Ser. No. 15/826,118, which was filed Nov. 29, 2017. Each of these applications is incorporated herein by reference in its entirety.
Number | Date | Country | |
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Parent | 17321659 | May 2021 | US |
Child | 18474586 | US | |
Parent | 15826118 | Nov 2017 | US |
Child | 17321659 | US |