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.
An annular blowout preventer (BOP) is installed on a wellhead to seal and control an oil and gas well during drilling operations. A drill string may be suspended inside an oil and gas well from a rig through the annular BOP into the well bore. During drilling operations, 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 well bore. In the event of a rapid invasion of formation fluid in the annulus, commonly known as a “kick,” the annular BOP may be actuated to seal the annulus and to control fluid pressure in the wellbore, thereby protecting well equipment disposed above the annular BOP. The construction of various components of the annular BOP can affect operation of the annular BOP.
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, the articles “a,” “an,” “the,” “said,” and the like, are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” “having,” and the like are intended to be inclusive and mean that there may be additional elements other than the listed elements. 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 relative to some fixed reference, such as the direction of gravity. The term “fluid” encompasses liquids, gases, vapors, and combinations thereof.
The present embodiments are generally directed to annular blowout preventers (BOPs). Annular BOPs may include a packer assembly (e.g., an annular packer assembly) disposed within a housing (e.g., an annular housing). A piston (e.g., annular piston) may be adjusted in a first axial direction to drive the packer assembly from an open position to a closed position to seal an annulus around a tubular member disposed through a central bore of the annular BOP or to close the central bore. In certain disclosed embodiments, the packer assembly includes a packer (e.g., annular packer) and one or more inserts (e.g., rigid inserts) coupled to, or formed within, the packer. In some embodiments, a first set of inserts may be arranged in a configuration that facilitates an annular type closing of the packer assembly (e.g., the inserts move axially upward and radially inward to contact one another). Additionally, a second set of inserts may be arranged in a configuration that facilitates an “iris-style” closing similar to that of an iris shutter of a camera. In certain embodiments, the second set of inserts are positioned beneath the first set of inserts to provide support to the first set of inserts and/or the packer. In other embodiments, the packer assembly may not include the second set of inserts, and instead, include an annular ring support disposed beneath the first set of inserts to support the first set of inserts and/or the packer. As discussed in more detail below, the disclosed embodiments may reduce extrusion of the packer as the annular BOP moves from the open position to the closed position, thereby reducing wear on components of the annular BOP, for example.
With the foregoing in mind,
To facilitate discussion, the BOP assembly 16 and its components may be described with reference to an axial axis or direction 30, a radial axis or direction 32, and a circumferential axis or direction 34. The BOP assembly 16 may include one or more annular BOPs 42 and/or one or more ram BOPs (e.g., shear ram, blind ram, blind shear ram, pipe ram, etc.). A central bore 44 (e.g., flow bore) extends through the one or more annular BOPs 42. As discussed in more detail below, each of the annular BOPs 42 includes a packer assembly (e.g., annular packer assembly) that is configured to be mechanically squeezed radially inwardly to seal about the tubular string 24 extending through the central bore 44 (e.g., to block an annulus about the tubular string 24) and/or to block flow through the central bore 44. The disclosed embodiments include annular BOPs 42 with a packer assembly having various features, such as one or more inserts coupled to a packer in a configuration that facilitates an annular style closing and/or an “iris-style” closing.
As discussed in more detail below, the piston 60 is configured to move relative to the housing 54 in the axial direction 30. For example, a fluid (e.g., a liquid and/or gas) may be provided to the chamber 72 via a first fluid conduit 76 to drive the piston 60 upwardly in the axial direction 30, as shown by arrow 78. As the piston 60 moves upwardly, the piston 60 drives the packer 62 upwardly. For example, an axially-facing surface 80 (e.g., e.g., packer-contacting surface, top surface, upper surface, or annular surface) of the piston 60 may apply an upward force against an axially-facing surface 82 (e.g., piston-contacting surface, bottom surface, lower surface, or annular surface) of the packer 62, driving the packer upwardly in the axial direction. When driven upwardly by the piston 60, the packer 62 may move upwardly in the axial direction and inwardly in the radial direction within the top 58 to a closed position in which the packer 62 seals around the tubular string 24 extending through the central bore 44 and/or blocks fluid through the central bore 44. In some embodiments, a second fluid conduit 84 is configured to provide a fluid (e.g., a liquid and/or gas) to the chamber 74 to drive the piston 60 downwardly in the axial direction, thereby causing the packer 62 to move from the closed position to the open position 50.
In the illustrated embodiment, the packer assembly 52 includes the packer 62, the first set of inserts 64, and/or the second set of inserts 66. The second set of inserts 66 may support the packer 62 and/or the first set of inserts 64 and may facilitate an “iris-style” closing to enable the packer assembly 62 to move inwardly in the radial direction from the open position 50 to the closed position. As shown, the first set of inserts 64 and the second set of inserts 66 are coupled to the packer 62 and are positioned circumferentially about the packer 62 (e.g., at discrete locations circumferentially about the packer 62). The first set of inserts 64 are configured to contact a radially-inner surface 86 (e.g., curved annular surface, dome-shaped surface, or semi-spherical surface) of the top 58, and are in an expanded position 88 while the annular BOP 42 is in the open position 50. In the expanded position 88, respective end portions 90 (e.g., radially-inner and/or upper end portions or tips) of adjacent inserts 64 are separated by a first distance 92 (e.g., along the circumferential axis 34). Additionally, opposed respective end portions of opposed inserts 66 (e.g., diametrically opposed on opposite sides of the central bore 44) define a first diameter 96 (e.g., along the radial axis 32). In certain embodiments, the distance between respective end portions 90 of adjacent inserts 64 and the distance between respective end portions 94 of opposed inserts 66 may decrease as the annular BOP 42 moves from the open position 50 to the closed position.
In the illustrated embodiment, the first set of inserts 64 and the second set of inserts 66 do not directly contact the piston 60 while the annular BOP 42 is in the open position 50. For example, the packer 62 may be positioned between the second set of inserts 66 and the piston 60 along the axial axis 30, and the second set of inserts 66 is separated from the axially-facing surface 82 of the packer 62 and/or the axially-facing surface 80 of the piston 60 by an axial distance. While the annular BOP 42 is in the open position 50, the axial distance may be equal to or greater than approximately 1, 2, 5, 10, 20, 30, 40, or 50 percent of a total height 100 (e.g., along the axial axis) of the packer assembly 52. In certain embodiments, the first set of inserts 64 and the second set of inserts 66 do not directly contact the piston 60 while the annular BOP 42 is in the open position 50, the closed position, or any position therebetween. However, in some embodiments, the second set of inserts 66 and the piston 60 may contact one another while the annular BOP 42 is in the open position 50, the closed position, and/or a position therebetween.
Further, while the packer 62 of the packer assembly 52 is transparent in the illustrated embodiment of
In some embodiments, the first set of inserts 64 and the second set of inserts 66 are separate components from one another. As such, the first set of inserts 64 and the second set of inserts 66 may move independently of one another. In other words, movement of the first set of inserts 64 does not cause movement of the second set of inserts 66, and vice versa. In such embodiments, movement (e.g., compression) of the packer 62 causes both the first set of inserts 64 and the second set of inserts 66 to move within the housing 54 of the annular BOP 42. In other embodiments, the first set of inserts 64 and the second set of inserts 66 may be coupled to one another via fasteners (e.g., threaded bolts and nuts), welds, and/or another suitable coupling technique. In still further embodiments, a first insert of the first set of inserts 64 and a second insert of the second set of inserts 66 may be formed as a single, unitary component. In other words, the first insert of the first set of inserts 64 may be integrated with the second insert of the second set of inserts 66. Further still, each insert of the first set of inserts 64 may be separate from one another, such that the inserts of the first set of inserts 64 are not linked or coupled to one another. Additionally, each insert of the second set of inserts 66 may be separate from one another, such that the inserts of the second set of inserts 66 are not linked or coupled to one another. Thus, each insert of the first set of inserts 64 and each insert of the second set of inserts 66 may move independent from the remaining inserts of the first set of inserts 64 and the second set of inserts 66, respectively. In other embodiments, some or all of the inserts of the first set of inserts 64 and/or some or all of the inserts of the second set of inserts 66 may be coupled or linked to one another.
The first set of inserts 64 are configured to move along the axis 30 toward the radially-inner surface 86. As the first set of inserts 64 contact the radially-inner surface 86, the first set of inserts 64 may begin to move radially inward along the axis 32 toward one another. The radially-inner surface 86 may gradually angle, taper, and/or curve toward the axis 30, such that the first set of inserts 64 are driven radially inward as the piston 60 drives the packer assembly 52 axially against the radially-inner surface 86. In other words, the radially-inner surface 86 acts as a cam and/or a wedge that drives the first set of inserts 64 radially inward along the axis 32 toward one another. As such, the first set of inserts 64 may contact one another (e.g., at least circumferentially facing side surfaces of adjacent inserts of the first set of inserts 64 contact one another). As shown in the illustrated embodiment of
Additionally, when transitioning between the open position 50 and the closed position 110, the second set of inserts 66 may not move along the axis 30, but move radially inward along the axis 32. For example, in the open position 50, each insert of the second set of inserts 66 may be in contact with one another in a first position 118, as shown in
As set forth above, the second set of inserts 66 may reduce the diameter 120 of the opening 122 formed by the second set of inserts 66 when the piston 60 is actuated to move the packer assembly 52 to the closed position 110. The second set of inserts 66 may thus provide structural support to the packer 62 as the packer 62 compresses within the housing 54 of the annular BOP 42. For example, the second set of inserts 66 move radially inward, and thus establish a barrier and/or support that blocks the packer 62 from compressing in a downward direction (e.g., represented by arrow 124) along the axis 30. In other words, the second set of inserts 66 may block the packer 62 from compressing and/or otherwise moving into the opening 122. As such, extrusion of the packer 62 may be reduced as a result of an increased surface area provided by the second set of inserts 66 in the closed position 110, thereby increasing an operational life of the packer assembly 52.
Additionally, the first insert 130 may include a sealing portion 140 that includes the respective end portion 90. As set forth above, the sealing portion 140 may include a tapered geometry (e.g., a wedge-shaped or pie-shaped sealing portion) to enable contact between adjacent inserts of the first set of inserts 64 when the packer assembly 52 is in the closed position 110.
Additionally, the sealing portion 140 may include a curvature that generally corresponds to a curvature of the radially-inner surface 86 of the top 58 the housing 54. Further still, the first insert 130 may include a coupling portion 142 (e.g., a leg portion) that extends between and couples the rounded portion 134 and the sealing portion 140 to one another. In some embodiments, the coupling portion 142 and/or the rounded portion 134 are configured to be disposed within a body of the packer 62 and the sealing portion 140 is configured to be positioned external to or flush with the body of the packer 62. As such, the sealing portion 140 may be configured to directly contact the radially-inner surface 86, which may cause rotational movement of the rounded portion 134 and/or the coupling portion 142.
The second insert 132 may be configured to move radially inward along the axis 32 as the packer 62 compresses due to the axial force exerted on the packer 62 by the piston 60. For instance, the second insert 132 includes a support portion 146 and an iris portion 148. In some embodiments, the support portion 146 is configured to be positioned proximate to and/or in contact with the rounded portion 134 of the first insert 130. The support portion 146 may include the surface 138 configured to support the first insert 130 and enable movement of the rounded portion 134 of the first insert 130 as the packer assembly 52 transitions between the open position 50 and the closed position 110. Further, the support portion 146 is configured to move radially inward within the central bore 44 (e.g., rotate radially inward along a spiral or parabolic path) as the packer 62 compresses within the central bore 44 as a result of the axial force applied by the piston 60. In some embodiments, the packer 62 contacts the radially-inner surface 86 and/or other surfaces within the housing 54 and compresses. Compression of the packer 62 then exerts a force on the second insert 132 causing the support portion 146 to move radially inward along the axis 32 and thus direct the iris portion 148 radially inward within the central bore 44. As the iris portion 148 moves radially inward within the central bore 44, the diameter 120 of the opening 122 formed by the second set of inserts 66 is reduced. Accordingly, each insert of the second set of inserts 66 move radially inward along the axis 32 to increase a radial surface area formed by the second set of inserts 66 that supports the packer 62. As such, a surface and/or barrier formed by the second set of inserts 66 is configured to block movement of the packer 62 in a downward direction along the axis 30 (e.g., in an opposite direction of arrow 78 shown in
The second set of inserts 160 may include a support portion 162 and an iris portion 164 similar to the second set of inserts 66 set forth above. As shown in the illustrated embodiment of
In some embodiments, the iris portion 164 of the second set of inserts 160 may include grooves 168 that are configured to increase friction between the packer 62 and the second set of inserts 160. For instance, the grooves 168 may cause the packer 62 (e.g., having an elastomeric material such as rubber) to maintain contact with the second set of inserts 160 as the packer assembly 52 transitions between the open position 50 and the closed position 110.
Accordingly, the packer 62 may stick to and/or otherwise maintain contact with the second set of inserts 160 to further reduce extrusion of the packer 62 (e.g., the packer 62 maintains contact with the second set of inserts 160 rather than collapsing into the opening 122). In any case, the support portion 162 of the second set of inserts 160 may be directed radially inward along the axis 32 within the central bore 44 (e.g., rotate radially inward along a spiral or parabolic path), thereby causing the iris portion 164 to move radially inward along the axis 32 within the central bore 44. As should be understood, each iris portion 164 of the second set of inserts 160 may be configured to maintain contact with iris portions 164 of adjacent inserts while moving radially inward along the axis 32. Accordingly, the diameter 120 of the opening 122 formed by the second set of inserts 66 is reduced without forming circumferential gaps between inserts of the second set of inserts 160. The second set of inserts 160 thus forms a surface and/or barrier that blocks movement of the packer 62 into the opening 122, thereby reducing extrusion of the packer 62.
As set forth above, the second insert 182 includes a support portion 162 and an iris portion 164 that are positioned within substantially the same plane 166. Further, the iris portion 164 of the second insert 182 includes the grooves 168 that are configured to maintain contact between the packer 62 and the second set of inserts 160 to further reduce extrusion of the packer 62. In some embodiments, the support portion 162 includes a rounded edge 192. The rounded edge 192 may facilitate movement of the second insert 182 radially inward along the axis 32 (e.g., rotational movement along the spiral or parabolic path) with respect to adjacent inserts of the second set of inserts 160. For example, the rounded edge 192 may urge and/or bias the second insert 182 toward an adjacent insert of the second set of inserts 160 as the second set of inserts 160 move radially inward along the axis 32 within the central bore 44. In any case, the second set of inserts 160 is configured to reduce the diameter 120 of the opening 122 formed by the second set of inserts 160 to provide support and/or a barrier that blocks the packer 62 from compressing and/or otherwise moving into the opening 122, thereby reducing extrusion and extending an operating life of the packer assembly 52.
In some embodiments, the support ring 200 includes a metal material, such as steel, stainless steel, aluminum, and/or another suitable metal. In other embodiments, the support ring 200 includes a non-metallic material, such as a polymeric material, a ceramic material, and/or another suitable non-metallic material. Additionally, the support ring 200 may include a variable thickness. For example, the support ring 200 may include a first thickness at the diameter 204 (e.g., an inner diameter defining the opening 202) and a second thickness at an outer diameter 208 of the support ring 200 (e.g., a diameter of the entire structure of the support ring 200). In some embodiments, the first thickness may be less than the second thickness. In other embodiments, the first thickness may be greater than the second thickness. Additionally or alternatively, the thickness of the support ring 200 may gradually increase or decrease from the first thickness to the second thickness in the radial direction from the diameter 204 to the outer diameter 208. While the illustrated embodiment of
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 intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the following appended claims.