Spooless compact wellhead system

Abstract

A hold-down ring assembly for a spooless wellhead housing includes a ring body configured to engage a first casing hanger and a second casing hanger to block separation of the first casing hanger and the second casing hanger from one another along an axial axis. The hold-down ring assembly includes multiple annular seal elements configured to seal against the second casing hanger. The hold-down ring assembly also includes one or more plugs configured to fit within one or more respective cement return openings of the second casing hanger. The multiple annular seal elements and the one or more plugs are configured provide a double pressure barrier across the one or more respective cement return openings of the second casing hanger.

Description

IS24.1188SPOOLESS COMPACT WELLHEAD SYSTEMCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 762160, titled “SPOOLESS COMPACT WELLHEAD SYSTEM” and filed February 24, 2025, which is incorporated by reference herein in its entirety for all purposes.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] Natural resources, such as oil and gas, are used as fuel to power vehicles, heat homes, and generate electricity. Once a desired natural resource is discovered below a surface, a mineral extraction system may be employed to access and extract the desired natural resource. The mineral extraction system may include a wellhead through which the desired natural resource is extracted. The wellhead may include or be coupled to a wide variety of components, such as a tubing hanger that supports a tubing, a casing hanger that supports a casing, valves, fluid conduits, and the like.SUMMARY

[0004] 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.Page 1 of 27SLB-PrivateIS24.1188

[0005] In certain embodiments, a hold-down ring assembly for a spooless wellhead housing includes a ring body configured to engage a first casing hanger and a second casing hanger to block separation of the first casing hanger and the second casing hanger from one another along an axial axis. The hold-down ring assembly includes multiple annular seal elements configured to seal against the second casing hanger. The hold-down ring assembly also includes one or more plugs configured to fit within one or more respective cement return openings of the second casing hanger. The multiple annular seal elements and the one or more plugs are configured provide a double pressure barrier across the one or more respective cement return openings of the second casing hanger.

[0006] In certain embodiments, a spooless wellhead includes a first casing hanger configured to support a first casing string within a wellbore. The spooless wellhead includes a second casing hanger configured to support a second casing string within the first casing string and within the wellbore, wherein the second casing hanger includes one or more openings to facilitate flow of cement returns axially across the second casing hanger during a cementing operation. The spooless wellhead also includes a hold-down ring assembly with a ring body configured to circumferentially surround a respective portion of the first casing hanger and a respective portion of the second casing hanger. The hold-down ring assembly also includes multiple seal elements configured to provide a pressure seal for the one or more openings.

[0007] In certain embodiments, a method includes landing a casing hanger at a spooless wellhead. The method also includes routing cement returns through one or more openings of the casing hanger. The method also inserting one or more plugs into the one or more openings of the casing hanger, wherein inserting the one or more plugs includes inserting a respective plug into each opening of the one or more openings of the second casing hanger. The method further includes landing a hold-down ring assembly on the casing hanger, wherein the hold-down ring assembly includes multiple annular seals to provide a double barrier for the one or more openings of the second casing hanger. The methodPage 2 of 27SLB-PrivateIS24.1188further includes performing a pressure test of the one or more plugs and the multiple annular seal elements using a test port of the hold-down ring assembly.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] 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:

[0009] FIG. 1 is a block diagram of a mineral extraction system, in accordance with an embodiment of the present disclosure;

[0010] FIG. 2 is a cross-sectional side view of an embodiment of a portion of a spooless wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein the spooless wellhead is coupled to a blowout preventer stack to enable a cementing operation;

[0011] FIG. 3 is a cross-sectional side view of an embodiment of the portion of the spooless wellhead and a hold-down ring assembly;

[0012] FIG. 4 is a cross-sectional side view of an embodiment of the portion of the spooless wellhead, wherein the hold-down ring assembly is engaged with a first casing hanger and a second casing hanger;

[0013] FIG. 5 is cross-sectional side view of an embodiment of a portion of the hold-down ring assembly within line 5-5 of FIG. 4;

[0014] FIG. 6 is cross-sectional side view of an embodiment of the portion of the spooless wellhead, wherein the hold-down ring assembly is engaged with the first casing hanger and the second casing hanger, and a tubing hanger is supported on the second casing hanger;

[0015] FIG. 7 is cross-sectional side view of an embodiment of the portion of the spooless wellhead, wherein a hold-down ring assembly with a separate seal carrier ring is engaged with the first casing hanger and the second casing hanger, and the tubing hanger is supported on the second casing hanger;Page 3 of 27SLB-PrivateIS24.1188

[0016] FIG. 8 is cross-sectional side view of an embodiment of a portion of the hold-down ring assembly with the separate seal carrier ring within line 8-8 of FIG.7;

[0017] FIG. 9 is cross-sectional side view of an embodiment of the portion of the spooless wellhead, wherein a threaded, single-barrier hold-down ring assembly is engaged with the first casing hanger and the second casing hanger, and the tubing hanger is supported on the second casing hanger;

[0018] FIG. 10 is cross-sectional side view of an embodiment of a portion of the threaded, single-barrier hold-down ring assembly within line 10-10 of FIG. 9;

[0019] FIG. 11 is cross-sectional side view of an embodiment of the portion of the spooless wellhead, wherein a single-barrier hold-down ring assembly is engaged with the first casing hanger and the second casing hanger, and the tubing hanger is supported on the second casing hanger;

[0020] FIG. 12 is cross-sectional side view of an embodiment of a portion of the single-barrier hold-down ring assembly within line 12-12 of FIG. 11 ;

[0021] FIG. 13 is cross-sectional side view of an embodiment of the portion of the spooless wellhead, wherein a single-barrier hold-down ring assembly with a separate seal carrier ring is engaged with the first casing hanger and the second casing hanger, and the tubing hanger is supported on the second casing hanger; and

[0022] FIG. 14 is cross-sectional side view of an embodiment of a portion of the single-barrier hold-down ring assembly with the separate seal carrier ring within line 14-14 of FIG. 13; and

[0023] FIG. 15 is a flow chart of an embodiment of a method of installing a spooless wellhead.DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0024] One or more specific embodiments of the present disclosure will be described below. These described embodiments are only exemplary of thePage 4 of 27SLB-PrivateIS24.1188present 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.

[0025] When introducing elements of various embodiments of the present disclosure, articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” “having,” and “based on” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters and / or conditions are not exclusive of other operating parameters and / or conditions of the disclosed embodiments.

[0026] Certain embodiments of the present disclosure generally relate to a spooless wellhead system. The spooless wellhead system may be compact (e.g., in width and / or height) relative to certain existing wellhead systems. The spooless wellhead system may include components that operate together to enable efficient casing installation, cementing operations, testing operations, hold-down and sealing operations, and tubing installation to form a spooless wellhead.

[0027] FIG. 1 is a block diagram of an embodiment of a mineral extraction system 10. The mineral extraction system 10 may be utilized to access and / or extract various natural resources (e.g., hydrocarbons, such as oil and / or natural gas) from the earth. As illustrated, the mineral extraction system 10 includes aPage 5 of 27SLB-PrivateIS24.1188spooless wellhead 12 (e.g., annular spooless wellhead) coupled to a mineral deposit 14 via a wellbore 16.

[0028] In the illustrated embodiment, the mineral extraction system 10 includes the spooless wellhead 12 that includes casing hanger(s) 18 and tubing hanger(s) 20. Each casing hanger 18 may support respective casing (e.g., a casing string) that is suspended in the wellbore 16. Each tubing hanger 20 may support respective tubing (e.g., a tubing string) that is suspended in the wellbore 16. As shown, the spooless wellhead 12 may also include a hold-down ring assembly 22, which may engage with the casing hanger(s) 18. For example, the hold-down ring assembly 22 may engage with a first casing hanger (e.g., outer casing hanger) and a second casing hanger (e.g., inner casing hanger) to block separation (e.g., axial separation) of the first casing hanger and the second casing hanger from one another.

[0029] The mineral extraction system 10 may also include pressure control equipment 24 (e.g., a blowout preventer (BOP), a seal flange, a backpressure valve, and so forth). The spooless wellhead 12 and the pressure control equipment 24 may provide respective bores that align with (e.g., fluidly couple to) the wellbore 16. Thus, a tool 26 may be inserted through the respective bores into the wellbore 16 to carry out various operations. Further, the natural resources extracted from the mineral deposit 14 may flow through the respective bores and be routed via certain components of the pressure control equipment (e.g., routed into a flowline). To facilitate discussion, the mineral extraction system 10 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.

[0030] FIG. 2 is a cross-sectional side view of an embodiment of a portion of the spooless wellhead 12, wherein the spooless wellhead 12 is coupled to a blowout preventer (BOP) stack 40 to enable a cementing operation. As shown, the spooless wellhead 12 includes the casing hanger(s) 18. In particular, the casing hanger(s) 18 includes a first casing hanger 42 (e.g., outer casing hanger;Page 6 of 27SLB-PrivateIS24.1188annular hanger) that supports a first casing string 44 (e.g., outer casing string; annular string), as well as a second casing hanger 46 (e.g., inner casing hanger; annular hanger) that support a second casing string 46 (e.g., inner casing string; annular string). The first casing string 44 and the second casing string 48 may extend into and / or through an outer conduit 50 (e.g., riser; conductor; annular conduit).

[0031] To install the first casing hanger 42 with the first casing string 44, the first casing hanger 42 and the first casing string 44 may be lowered (e.g., via a running tool) to land on a pack-off ring 52. Then, cementing operations may be carried out to block movement (e.g., axial movement) of the first casing hanger 42 and the first casing string 44 relative to the wellbore 16 of FIG. 1.

[0032] Then, to install the second casing hanger 46 with the second casing string 48, the second casing hanger 46 and the second casing string 48 may be lowered (e.g., via a running tool 54) to land on the first casing hanger 42. For example, the second casing hanger 46 may land on a shoulder 56 (e.g., annular shoulder) of the first casing hanger 42. One or more seal elements 58 (e.g., annular seal elements) may provide one or more annular seals between the first casing hanger 42 and the second casing hanger 46 (e.g., between a radially inner surface of the first casing hanger 42 and a radially outer surface of the second casing hanger 46). Then, cementing operations may be carried out to block movement (e.g., axial movement) of the second casing hanger 46 and the second casing string 48 relative to the wellbore 16 of FIG. 1.

[0033] In certain embodiments, as shown by arrow 60 in FIG. 2, cement returns resulting from the cementing operations may flow through a cement returns pathway toward other equipment at surface. In certain embodiments, the cement returns pathway include may one or more openings 62 (e.g., cement return openings) formed in the second casing hanger 46. For example, the one or more openings 62 formed in the second casing hanger 46 may include multiple openings 62 distributed about the circumferential axis 34 (e.g. the multiple openings 62 are multiple discrete openings, each with a respective inletPage 7 of 27SLB-PrivateIS24.1188exposed to an annular space between the first casing string 44 and the second casing string 48 and with a respective outlet exposed to the other equipment at the surface, such as via an annular space between the casing running tool 54 and the BOP stack 40). It should be appreciated that the cement returns pathway may be formed by and / or include the annular space defined between the first casing string 44 and the second casing string 48, the one or more openings 62 of the second casing hanger 46, one or more openings of the running tool 54, the annular space defined between the running tool 54 and the BOP stack 40, and / or any other suitable annular space(s) and / or opening(s).

[0034] As shown, the BOP stack 40 may be coupled to the spooless wellhead 12 at least during the cementing operations for the second casing hanger 46 and the first casing string 48. The BOP stack 40 may be coupled to the first casing hanger 42 via one or more fasteners 64 (e.g., tie-down screws; distributed about the circumferential axis 34). After the cementing operations for the second casing hanger 46 and the first casing string 48, the BOP stack 40 and the running tool 54 may be removed (e.g., separated from the spooless wellhead 12; separated from the first casing hanger 42 and the second casing hanger 46, respectively).

[0035] FIG. 3 is a cross-sectional side view of an embodiment of the portion of the spooless wellhead 12 and the hold-down ring assembly 22. Indeed, after the BOP stack 40 of FIG. 2 and the running tool 54 of FIG. 2 are removed, the holddown ring assembly 22 may be installed at the spooless wellhead 12. As shown in FIG. 3, the hold-down ring assembly 22 may include a ring body 70 (e.g., annular body) that supports multiple seal elements 72 (e.g., annular seal elements) and a hold-down ring 74 (e.g., c-ring; multiple discrete fasteners arranged about the circumferential axis 34). The ring body 70 includes a stepped radially inner surface that is configured correspond to and / or interface with (e.g., contact; land on) the first casing hanger 42 and the second casing hanger 46. The hold-down ring assembly 22 may also be considered to include or work in conjunction with one or more plugs 76 (e.g., cement plugs; cement flow through plugs) that are configured to be seated within (e.g., inserted into; threaded into)Page 8 of 27SLB-PrivateIS24.1188the one or more openings 62 of the second casing hanger 46 (e.g., one plug 76 per opening 62). As used herein, the one or more plugs 76 may also be considered to be one or more seal elements that provide one or more seals at the one or more openings 62 of the second casing hanger 46.

[0036] To install the hold-down ring assembly 22, the one or more plugs 76 may be inserted into end portions (e.g., outlet portions) of the one or more openings 62 of the second casing hanger 46. Then, the ring body 70 may be lowered (e.g., via a running tool; axially without rotation) to land on the first casing hanger 42 and / or the second casing hanger 46, as shown in FIG. 4.

[0037] FIG. 4 is a cross-sectional side view of an embodiment of the portion of the spooless wellhead 12, wherein the hold-down ring assembly 22 is engaged with the first casing hanger 42 and the second casing hanger 46. When the ring body 70 reaches a landed position on the first casing hanger 42 and / or the second casing hanger 46, the hold-down ring 74 may engage a corresponding groove 80 (e.g., annular grove) formed in the first casing hanger 42 (e.g., a radially outer surface of the first casing hanger 42) to block movement of the ring body 70 relative to the first casing hanger 42. For example, the hold-down ring 74 may engage the corresponding groove 80 by contracting into the corresponding groove 80 upon being aligned with the corresponding groove 70 along the axial axis 30 and / or via tightening one or more fasteners (e.g., tie-down screws) that are distributed about the circumferential axis 34.

[0038] Additional details of the hold-down ring assembly 22 are shown in FIG.5. In particular, FIG. 5 includes a cross-sectional side view of an embodiment of a portion of the hold-down ring assembly 22 within line 5-5 of FIG. 4. As shown, the hold-down ring assembly 22 is engaged with the first casing hanger 42 and the second casing hanger 46. In particular, the hold-down ring 74 is engaged with (e.g., extends into; overlaps along the radial direction 32) the corresponding groove 80 to block movement of the ring body 70 relative to the first casing hanger 42. A respective interface 82 between opposed surfaces (e.g., opposed axially-facing surfaces) of the ring body 70 and the first casing hanger 42 blocksPage 9 of 27SLB-PrivateIS24.1188movement of the ring body 70 relative to the first casing hanger 42. Additionally, a respective interface 82 between opposed surfaces (e.g., opposed axially-facing surfaces) of the ring body 70 and the second casing hanger 46 blocks movement of the ring body 70 relative to the second casing hanger 46. As such, the ring body 70 of the hold-down ring assembly 22 may land on and / or engage both the first casing hanger 42 and the second casing hanger 46, and may also circumferentially surround at least a portion of the first casing hanger 42 and at least a portion of the second casing hanger 46.

[0039] Further, as shown, one plug 76 is inserted into a respective opening 62 formed in the second casing hanger 46. The multiple seal elements 72 form multiple annular seals between the ring body 70 and the second casing hanger 46. In particular, the multiple seal elements 72 include a first seal element that forms a first annular seal on one side of the one or more plugs 76 (and respective end portions of the one or more openings 62) and a second seal element that forms a second annular seal on another side of the one or more plugs 76 (and the respective end portions of the one or more openings 62) relative to the axial axis 30. Additionally, the one or more seal elements 58 provide the one or more annular seals between the first casing hanger 42 and the second casing hanger 46. These features may facilitate seal testing (e.g., pressure testing) after the cementing operations to cement the second casing string supported by the second casing hanger 46, as may be understood by returning to FIG. 4.

[0040] With reference to FIG. 4, a lower testing assembly 90 that includes a test port 92 formed in the second casing hanger 46 may enable testing the one or more seal elements 58 that provide the one or more annular seals between the first casing hanger 42 and the second casing hanger 46. Additionally, an upper testing assembly 94 that includes a test port 96 formed in the ring body 70 and the one or more plugs 76 may enable testing the one or more plugs 76 and / or the multiple seal elements 72 that provide the one or more annular seals between the second casing hanger 46 and the ring body 70 (e.g., between aPage 10 of 27SLB-PrivateIS24.1188radially outer surface of the second casing hanger 46 and a radially inner surface of the ring body 70).

[0041] FIG. 6 is cross-sectional side view of an embodiment of the portion of the spooless wellhead 12, wherein the hold-down ring assembly 22 is engaged with the first casing hanger 42 and the second casing hanger 46, and a tubing hanger 100 is supported on the second casing hanger 46. After the installation of the hold-down ring assembly 22 and pressure tests, additional equipment (e.g., a landing joint, a BOP adapter, a BOP) may be coupled to the second casing hanger 46. For example, a threaded flange 104 may be threaded onto the second casing hanger 46, and the additional equipment may be coupled to the threaded flange 104 (e.g., via one or more fasteners 105, such as bolts). Then, the tubing hanger 100 (e.g., one of the one or more tubing hanger(s) 20 of FIG.1) may be installed, such as via landing the tubing hanger 100 on the second casing hanger 46. Then, a seal flange 106 and / or other components (e.g., valves 108) may be installed to prepare for further operations.

[0042] In FIGS. 3-6, the hold-down ring assembly 22 supports the multiple seal elements 72 in the ring body 22. Further, in FIGS. 3-6, the hold-down ring assembly 22 includes or works in conjunction with the one or more plugs 76. Thus, in FIGS. 3-6, the hold-down ring assembly 22 may be considered to provide a double-barrier to pressure via the multiple seal elements 72 in the ring body 22 and the one or more plugs 76. Further, in FIGS. 3-6, the hold-down ring assembly 22 may be considered to include integrated seals (e.g., the multiple seal elements 72) and may be installed axially without rotation (e.g., via the holddown ring 74; lowered; without threading onto the first casing hanger 42 or the second casing hanger 46).

[0043] It is presently recognized that the hold-down ring assembly 22 of FIG.1 and to be utilized with the spooless wellhead 12 of FIGS. 1 and 2 may include various features. Accordingly, FIGS. 7-14 illustrate examples of various features that may be implemented for the hold-down ring assembly 22 of FIG. 2.Page 11 of 27SLB-PrivateIS24.1188

[0044] FIG. 7 is cross-sectional side view of an embodiment of the portion of the spooless wellhead 12, wherein the hold-down ring assembly 22 with a separate seal carrier ring 110 is engaged with the first casing hanger 42 and the second casing hanger 46, and the tubing hanger 100 is supported on the second casing hanger 46. FIG. 8 is cross-sectional side view of an embodiment of a portion of the hold-down ring assembly 22 with the separate seal carrier ring 110 within line 8-8 of FIG. 7.

[0045] As shown in FIGS. 7 and 8, the hold-down ring assembly 22 may include a ring body 112 (e.g., annular body) that is configured to couple to the first casing hanger 42 via a threaded interface 114 (e.g., via rotation; between a radially outer surface of the first casing hanger 42 and a radially inner surface of the ring body 112). In FIGS. 7 and 8, the hold-down ring assembly 22 may also include the separate seal carrier ring 110, which may support multiple seal elements 116 (e.g., annular seal elements). As shown, the hold-down ring assembly 22 may also be considered to include or work in conjunction with one or more plugs 76 that are configured to be seated within the one or more openings 62 of the second casing hanger 46 (e.g., one plug 76 per opening 62). In certain instances, the ring body 112 and the separate seal carrier ring 110 may be collectively referred to as a sealing ring assembly.

[0046] To install the hold-down ring assembly 22 of FIGS. 7 and 8, the one or more plugs 76 may be inserted into the end portions (e.g., outlet portions) of the one or more openings 62 of the second casing hanger 46. Then, the ring body 112 may be lowered (e.g., via a running tool; axially with rotation) to land on the first casing hanger 42 and / or the second casing hanger 46, as well as to thread onto the first casing hanger 42 via the threaded interface 114. Thus, the holddown ring assembly 22 of FIGS. 7 and 8 may engage both the first casing hanger 42 and the second casing hanger 46, and may also circumferentially surround at least a portion of the first casing hanger 42 and at least a portion of the second casing hanger 46.Page 12 of 27SLB-PrivateIS24.1188

[0047] The seal carrier ring 110 may be installed with the ring body 112 and / or after the ring body 112. When installed, the seal carrier ring 110 may contact and / or be supported on the ring body 112. The multiple seal elements 116 form multiple annular seals between the seal carrier ring 110 and the second casing hanger 46. In particular, the multiple seal elements 116 include a first seal element that forms a first annular seal on one side of the one or more plugs 76 (and respective end portions of the one or more openings 62) and a second seal element that forms a second annular seal on another side of the one or more plugs 76 (and the respective end portions of the one or more openings 62) relative to the axial axis 30. Additionally, the one or more seal elements 58 provide the one or more annular seals between the first casing hanger 42 and the second casing hanger 46. These and other features (e.g., a test port 118 formed in the seal carrier ring 110) may facilitate seal testing (e.g., pressure testing) after the cementing operations to cement the second casing string supported by the second casing hanger 46, as described herein at least with respect to FIG. 4, for example.

[0048] With respect to FIGS. 7 and 8, after the installation of the hold-down ring assembly 22 and pressure tests, the seal carrier ring 110 may remain in place as part of the hold-down ring assembly 22 and the spooless wellhead 12. Then, additional equipment (e.g., a landing joint, a BOP adapter, a BOP) may be coupled to the second casing hanger 46. For example, the threaded flange 104 may be threaded onto the second casing hanger 46, and the additional equipment may be coupled to the threaded flange 104 (e.g., via one or more fasteners 105, such as bolts). Then, the tubing hanger 100 (e.g., one of the one or more tubing hanger(s) 20 of FIG. 1) may be installed, such as via landing the tubing hanger 100 on the second casing hanger 46. Then, the seal flange 106 and / or other components (e.g., the valves 108) may be installed to prepare for further operations.

[0049] In FIGS. 7 and 8, the hold-down ring assembly 22 is a separate structure from the seal carrier ring 110 that supports the multiple seal elements 116. Further, in FIGS. 7 and 8, the hold-down ring assembly 22 includes orPage 13 of 27SLB-PrivateIS24.1188works in conjunction with the one or more plugs 76. Thus, in FIGS. 7 and 8, the hold-down ring assembly 22 may be considered to provide a double-barrier to pressure via the multiple seal elements 116 in the seal carrier ring 110 and the one or more plugs 76. Further, in FIGS. 7 and 8, the hold-down ring assembly 22 may be installed with rotation (e.g., via the threaded interface 114).

[0050] FIG. 9 is cross-sectional side view of an embodiment of the portion of the spooless wellhead 12, wherein a threaded, single-barrier hold-down ring assembly 22 (also referred to as “the hold-down ring assembly 22” in description of FIGS. 9 and 10) is engaged with the first casing hanger 42 and the second casing hanger 46, and the tubing hanger 100 is supported on the second casing hanger 46. FIG. 10 is cross-sectional side view of an embodiment of a portion of the threaded, single-barrier hold-down ring assembly 22 within line 10-10 of FIG.9.

[0051] As shown in FIGS. 9 and 10, the hold-down ring assembly 22 may include a ring body 122 (e.g., annular body) that is configured to couple to the first casing hanger 42 via a threaded interface 124 (e.g., via rotation; ; between a radially outer surface of the first casing hanger 42 and a radially inner surface of the ring body 122). In FIGS. 9 and 10, the hold-down ring assembly 22 may also include a separate seal carrier ring 126, which may support multiple seal elements 128 (e.g., annular seal elements). As shown, the hold-down ring assembly 22 may also be considered to include or work in conjunction with one or more plugs 76 that are configured to be seated within the one or more openings 62 of the second casing hanger 46 (e.g., one plug 76 per opening 62). In certain instances, the ring body 122 and the separate seal carrier ring 126 may be collectively referred to as a sealing ring assembly.

[0052] To install the hold-down ring assembly 22 of FIGS. 9 and 10, the one or more plugs 76 may be inserted into the end portions (e.g., outlet portions) of the one or more openings 62 of the second casing hanger 46. Then, the ring body 122 may be lowered (e.g., via a running tool; axially with rotation) to land on the first casing hanger 42 and / or the second casing hanger 46, as well as toPage 14 of 27SLB-PrivateIS24.1188thread onto the first casing hanger 42 via the threaded interface 124. Thus, the hold-down ring assembly 22 of FIGS. 9 and 10 may engage both the first casing hanger 42 and the second casing hanger 46, and may also circumferentially surround at least a portion of the first casing hanger 42 and at least a portion of the second casing hanger 46.

[0053] The seal carrier ring 126 may be temporarily installed, such as with the ring body 122 and / or after the ring body 122. When temporarily installed, the seal carrier ring 126 may contact and / or be supported on the ring body 122. The multiple seal elements 128 form multiple annular seals between the seal carrier ring 126 and the second casing hanger 46. In particular, the multiple seal elements 128 include a first seal element that forms a first annular seal on one side of the one or more plugs 76 (and respective end portions of the one or more openings 62) and a second seal element that forms a second annular seal on another side of the one or more plugs 76 (and the respective end portions of the one or more openings 62) relative to the axial axis 30. Additionally, the one or more seal elements 58 provide the one or more annular seals between the first casing hanger 42 and the second casing hanger 46. These and other features (e.g., a test port 130 formed in the seal carrier ring 126) may facilitate seal testing (e.g., pressure testing) after the cementing operations to cement the second casing string supported by the second casing hanger 46, as described herein at least with respect to FIG. 4, for example.

[0054] With respect to FIGS. 9 and 10, after the installation of the hold-down ring assembly 22 and pressure tests, the seal carrier ring 126 may be removed (e.g., withdrawn from the spooless wellhead 12). Then, additional equipment (e.g., a landing joint, a BOP adapter, a BOP) may be coupled to the second casing hanger 46. For example, the threaded flange 104 may be threaded onto the second casing hanger 46, and the additional equipment may be coupled to the threaded flange 104 (e.g., via one or more fasteners 105, such as bolts). Then, the tubing hanger 100 (e.g., one of the one or more tubing hanger(s) 20 of FIG. 1) may be installed, such as via landing the tubing hanger 100 on thePage 15 of 27SLB-PrivateIS24.1188second casing hanger 46. Then, the seal flange 106 and / or other components (e.g., the valves 108) may be installed to prepare for further operations.

[0055] In FIGS. 9 and 10, the hold-down ring assembly 22 is a separate structure from the seal carrier ring 126 that supports the multiple seal elements 128. However, the seal carrier ring 126 is intended for temporary use during the pressure tests, and the seal carrier ring 126 is intended to be removed after the pressure tests. Thus, while the seal carrier ring 126 and the one or more plugs 76 enable the pressure tests, the hold-down ring assembly 22 may be considered to provide a single-barrier to pressure via the one or more plugs 76 (e.g., after the pressure test; after removal of the seal carrier ring 126; during the further operations). Further, in FIGS. 9 and 10, the hold-down ring assembly 22 may be installed with rotation (e.g., via the threaded interface 114).

[0056] FIG. 11 is cross-sectional side view of an embodiment of the portion of the spooless wellhead 12, wherein a single-barrier hold-down ring assembly 22 (also referred to as “the hold-down ring assembly 22” in description of FIGS. 11 and 12) is engaged with the first casing hanger 42 and the second casing hanger 46, and the tubing hanger 100 is supported on the second casing hanger 46. FIG.12 is cross-sectional side view of an embodiment of a portion of the single-barrier hold-down ring assembly 22 within line 12-12 of FIG. 11.

[0057] As shown in FIGS. 11 and 12, the hold-down ring assembly 22 may include a ring body 132 (e.g., annular body) that is configured to couple to the first casing hanger 42 via a hold-down ring 134 (e.g., c-ring; multiple discrete fasteners arranged about the circumferential axis 34). In FIGS. 11 and 12, the ring body 132 may be devoid of seal elements (e.g., annular seal elements) and / or no annular seals may be provided between the ring body 132 and the second casing hanger 46. As shown, the hold-down ring assembly 22 may also be considered to include or work in conjunction with one or more plugs 76 that are configured to be seated within the one or more openings 62 of the second casing hanger 46 (e.g., one plug 76 per opening 62).Page 16 of 27SLB-PrivateIS24.1188

[0058] To install the hold-down ring assembly 22 of FIGS. 11 and 12, the one or more plugs 76 may be inserted into the end portions (e.g., outlet portions) of the one or more openings 62 of the second casing hanger 46. Then, the ring body 132 may be lowered (e.g., via a running tool; axially without rotation) to land on the first casing hanger 42 and / or the second casing hanger 46, as well as to engage the first casing hanger 42 (e.g., a radially outer surface of the first casing hanger 42) via the hold-down ring 134. Thus, the hold-down ring assembly 22 of FIGS. 11 and 12 may engage both the first casing hanger 42 and the second casing hanger 46, and may also circumferentially surround at least a portion of the first casing hanger 42 and at least a portion of the second casing hanger 46.

[0059] Additionally, as shown in FIGS. 11 and 12, the one or more seal elements 58 provide the one or more annular seals between the first casing hanger 42 and the second casing hanger 46. These and other features (e.g., the test port 92) may facilitate seal testing (e.g., pressure testing) the one or more seal elements 58 after the cementing operations to cement the second casing string supported by the second casing hanger 46, as described herein at least with respect to FIG. 4, for example.

[0060] With respect to FIGS. 11 and 12, after the installation of the hold-down ring assembly 22 and pressure tests, additional equipment (e.g., a landing joint, a BOP adapter, a BOP) may be coupled to the second casing hanger 46. For example, the threaded flange 104 may be threaded onto the second casing hanger 46, and the additional equipment may be coupled to the threaded flange 104 (e.g., via one or more fasteners 105, such as bolts). Then, the tubing hanger 100 (e.g. , one of the one or more tubing hanger(s) 20 of FIG. 1 ) may be installed, such as via landing the tubing hanger 100 on the second casing hanger 46. Then, the seal flange 106 and / or other components (e.g., the valves 108) may be installed to prepare for further operations.

[0061] In FIGS. 11 and 12, the hold-down ring assembly 22 is devoid of seal elements (e.g., annular seal elements) and / or no annular seals may be provided between the ring body 132 and the second casing hanger 46. As such, in FIGS.Page 17 of 27SLB-PrivateIS24.118811 and 12 the hold-down ring assembly 22 may be considered to provide a single-barrier to pressure via the one or more plugs 76 (e.g., during the further operations). Additionally, even though the ring body 134 may circumferentially surround and / or support the one or more plugs 76 within the end portions of the one or more openings 62 of the second casing hanger body 46, the hold-down ring assembly 22 may not enable pressure tests about the end portions of the one or more openings 62 of the second casing hanger 46. Further, in FIGS. 11 and 12, the hold-down ring assembly 22 may be installed axially without rotation (e.g., via the hold-down ring 134; lowered; without threading onto the first casing hanger 42 or the second casing hanger 46).

[0062] FIG. 13 is cross-sectional side view of an embodiment of the portion of the spooless wellhead 12, wherein a single-barrier hold-down ring assembly 22 (also referred to as “the hold-down ring assembly 22” in description of FIGS. 11 and 12) with a separate seal carrier ring 140 is engaged with the first casing hanger 42 and the second casing hanger 46, and the tubing hanger 100 is supported on the second casing hanger. FIG. 14 is cross-sectional side view of an embodiment of a portion of the single-barrier hold-down ring assembly 22 with the separate seal carrier ring 140 within line 14-14 of FIG. 13.

[0063] As shown in FIGS. 13 and 14, the hold-down ring assembly 22 may include a ring body 142 (e.g., annular body) that is configured to couple to the first casing hanger 42 via a threaded interface 144 (e.g., via rotation; ; between a radially outer surface of the first casing hanger 42 and a radially inner surface of the ring body 142). In FIGS. 13 and 14, the hold-down ring assembly 22 may also include the separate seal carrier ring 140, which may support multiple seal elements 146 (e.g., annular seal elements). As shown, the hold-down ring assembly 22 does not include and / or does not work in conjunction with one or more plugs that are configured to be seated within the one or more openings 62 of the second casing hanger 46; however, it should be appreciated that in some cases the hold-down ring assembly 22 may include or be utilized in conjunction with one or more plugs as described herein (e.g., the one or more plugs 76 of FIGS. 3-12).Page 18 of 27SLB-PrivateIS24.1188

[0064] To install the hold-down ring assembly 22 of FIGS. 13 and 14, the ring body 142 may be lowered (e.g., via a running tool; axially with rotation) to land on the first casing hanger 42 and / or the second casing hanger 46, as well as to thread onto the first casing hanger 42 via the threaded interface 144. Thus, the hold-down ring assembly 22 of FIGS. 13 and 14 may engage both the first casing hanger 42 and the second casing hanger 46, and may also circumferentially surround at least a portion of the first casing hanger 42 and at least a portion of the second casing hanger 46.

[0065] The seal carrier ring 140 may be installed with the ring body 142 and / or before the ring body 142. When installed, the seal carrier ring 140 may contact, be covered by, and / or be supported by the ring body 142. The multiple seal elements 146 form multiple annular seals between the seal carrier ring 140 and the second casing hanger 46. In particular, the multiple seal elements 146 include one or more first seal elements that form one or more first annular seals on one side of respective end portions of the one or more openings 62 relative to the axial axis 30, as well as one or more second seal elements that form one or more second annular seals on another side of the respective end portions of the one or more openings 62 relative to the axial axis 30. Additionally, the one or more seal elements 58 provide the one or more annular seals between the first casing hanger 42 and the second casing hanger 46. These and other features (e.g., the test port 92) may facilitate seal testing (e.g., pressure testing) the one or more seal elements 58 after the cementing operations to cement the second casing string supported by the second casing hanger 46, as described herein at least with respect to FIG. 4, for example.

[0066] With respect to FIGS. 13 and 14, after the installation of the hold-down ring assembly 22 and pressure tests, the seal carrier ring 140 may remain in place as part of the hold-down ring assembly 22 and the spooless wellhead 12. Then, additional equipment (e.g., a landing joint, a BOP adapter, a BOP) may be coupled to the second casing hanger 46. For example, the threaded flange 104 may be threaded onto the second casing hanger 46, and the additional equipment may be coupled to the threaded flange 104 (e.g., via one or morePage 19 of 27SLB-PrivateIS24.1188fasteners 105, such as bolts). Then, the tubing hanger 100 (e.g., one of the one or more tubing hanger(s) 20 of FIG. 1) may be installed, such as via landing the tubing hanger 100 on the second casing hanger 46. Then, the seal flange 106 and / or other components (e.g., the valves 108) may be installed to prepare for further operations.

[0067] In FIGS. 13 and 14, the hold-down ring assembly 22 is a separate structure from the seal carrier ring 140 that supports the multiple seal elements 146. However, in FIGS. 13 and 14, the hold-down ring assembly 22 does not include and does not work in conjunction with one or more plugs at the respective end portions of the one or more openings 62 of the second casing hanger 46. Thus, in FIGS. 13 and 14, the hold-down ring assembly 22 may be considered to provide a single-barrier to pressure via the multiple seal elements 146 in the seal carrier ring 140. Further, in FIGS. 13 and 14, the hold-down ring assembly 22 may be installed with rotation (e.g., via the threaded interface 144).

[0068] FIG. 15 is a flow diagram of an embodiment of a method 150 of assembly of a spooless wellhead. The method 150 disclosed herein includes various steps represented by blocks. Although the method 150 illustrates the blocks in a certain sequence, it should be understood that the blocks may be performed in any suitable order, certain blocks may be performed simultaneously, certain blocks may be omitted, and / or additional blocks may be added.

[0069] In block 152, the method 150 may include running a second casing hanger to land on a first casing hanger. In block 154, the method 150 may include performing a cementing operation that includes routing cement returns axially across the second casing hanger. In block 156, the method 150 may include removing a blowout preventer (BOP) stack.

[0070] In block 158, the method 150 may include running a hold-down ring assembly to engage the first casing hanger and / or the second casing hanger. As set forth herein, the hold-down ring assembly may include various features, such as a ring body, integrated seal elements, a test port, a separate seal carrier ring, a hold-down ring, threads to form a threaded interface with the second casingPage 20 of 27SLB-PrivateIS24.1188hanger, one or more surfaces that oppose one or more other surfaces of the first casing hanger and / or the second casing hanger to form one or more interfaces that block relative movement between the first casing hanger and / or the second casing hanger, and / or any other suitable features. In certain embodiments, the hold-down ring assembly may include or be used in conjunction with one or more plugs that are configured to insert into respective end portions of one or more openings formed in the second casing hanger (e.g., the one or more openings that enable flow of cement returns axially across the second casing hanger).

[0071] In block 160, the method 150 may include performing pressure tests, such as between lower annular seals and / or between upper annular seals. For example, the hold-down ring assembly may include the integrated seals and / or the separate seal carrier ring as the upper annular seals (e.g., seal against a radially outer surface of the second casing hanger). Further, the ring body and / or the separate seal carrier ring may include a respective test port to test pressure between the upper annular seals. In some embodiments, the lower annular seals are between the first casing hanger, and the second casing hanger, and the second casing hanger includes a respective test port to test pressure between the lower annular seals.

[0072] In block 162, the method 150 may include running a tubing hanger to land on the second casing hanger. In block 164, the method 150 may include installing additional equipment, such as a BOP stack and a seal flange to support further operations. In this way, the method 150 may provide the spooless wellhead that includes the first casing hanger (e.g., without a spool or housing about the first casing hanger), the second casing hanger (e.g., without a spool or housing about the second casing hanger), and the hold-down ring assembly (e.g., without a spool or housing about the hold-down ring assembly).

[0073] 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 formsPage 21 of 27SLB-PrivateIS24.1188disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. For example, any features shown or described with reference to FIGS. 1-15 may be combined and / or exchanged in any suitable manner.

[0074] 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).Page 22 of 27SLB-Private

Claims

IS24.1188CLAIMS1. A hold-down ring assembly for a spooless wellhead housing, the holddown ring assembly comprising:a ring body configured to engage a first casing hanger and a second casing hanger to block separation of the first casing hanger and the second casing hanger from one another along an axial axis;a plurality of annular seal elements configured to seal against the second casing hanger; andone or more plugs configured to fit within one or more respective cement return openings of the second casing hanger;wherein the plurality of annular seal elements and the one or more plugs are configured provide a double pressure barrier across the one or more respective cement return openings of the second casing hanger.

2. The hold-down ring assembly of claim 1, wherein the ring body is configured to couple to the first casing hanger via a plurality of fasteners or a threaded interface.

3. The hold-down ring assembly of claim 1, wherein the ring body is configured to couple to a radially outer surface of the first casing hanger.

4. The hold-down ring assembly of claim 1, wherein the plurality of annular seal elements are integrated into the ring body.

5. The hold-down ring assembly of claim 1, wherein the plurality of annular seal elements comprise a first annular seal element and a second annular seal element, the first annular seal element is configured to form a first annular seal on a first side of the one or more respective cement return openings of the second casing hanger relative to the axial axis, and the second annular sealPage 23 of 27SLB-PrivateIS24.1188element is configured to form a second annular seal on a second side of the one or more respective cement return openings of the second casing hanger relative to the axial axis.

6. The hold-down ring assembly of claim 1 , comprising a test port to enable a pressure test between the plurality of annular seal elements.

7. The hold-down ring assembly of claim 6, wherein the test port is formed in the ring body.

8. The hold-down ring assembly of claim 1, wherein the first casing hanger and the second casing hanger are not surrounded by a spool.

9. The hold-down ring assembly of claim 1, comprising a separate seal carrier, wherein the plurality of annular seal elements are supported by the separate seal carrier.

10. A spooless wellhead, comprising:a first casing hanger configured to support a first casing string within a wellbore;a second casing hanger configured to support a second casing string within the first casing string and within the wellbore, wherein the second casing hanger comprises one or more openings to facilitate flow of cement returns axially across the second casing hanger during a cementing operation; anda hold-down ring assembly comprising;a ring body configured to circumferentially surround a respective portion of the first casing hanger and a respective portion of the second casing hanger; anda plurality of seal elements configured to provide a pressure seal for the one or more openings.Page 24 of 27SLB-PrivateIS24.118811. The spooless wellhead of claim 10, wherein the ring body is configured to engage the first casing hanger and the second casing hanger to block separation of the first casing hanger and the second casing hanger from one another along an axial axis.

12. The spooless wellhead of claim 10, wherein the ring body is configured to couple to the first casing hanger via a hold-down ring or a threaded interface.

13. The spooless wellhead of claim 10, wherein the ring body is configured to couple to a radially outer surface of the first casing hanger.

14. The spooless wellhead of claim 10, wherein the plurality of seal elements comprise a plurality of annular seal elements integrated into the ring body and configured to provide a plurality of annular seals between the hold-down ring assembly and the second casing hanger to provide the pressure seal for the one or more openings.

15. The spooless wellhead of claim 10, wherein the plurality of seal elements comprises:a plurality of annular seal elements; andone or more plugs configured to fit within the one or more respective openings of the second casing hanger;wherein the plurality of annular seal elements and the one or more plugs are configured to provide a double pressure barrier as the pressure seal for the one or more openings.

16. The spooless wellhead of claim 10, wherein the plurality of seal elements comprises a plurality of annular seal elements, and the hold-down ring assembly comprises a test port to between the plurality of seal elements along an axial axisPage 25 of 27SLB-PrivateIS24.118817. The spooless wellhead of claim 16, wherein the test port is formed in the ring body.

18. The spooless wellhead of claim 10, wherein the spooless wellhead is devoid of a spool about the first casing hanger and the second casing hanger.

19. The spooless wellhead of claim 10, wherein the hold-down ring assembly comprises a separate seal carrier, and the plurality of seal elements are supported by the separate seal carrier.

20. A method, comprising:landing a casing hanger at a spooless wellhead;routing cement returns through one or more openings of the casing hanger;inserting one or more plugs into the one or more openings of the casing hanger, wherein inserting the one or more plugs comprises inserting a respective plug into each opening of the one or more openings of the casing hanger;landing a hold-down ring assembly on the casing hanger, wherein the hold-down ring assembly comprises a plurality of annular seals to provide a double barrier for the one or more openings of the casing hanger; and performing a pressure test of the one or more plugs and the plurality of annular seals using a test port of the hold-down ring assembly.Page 26 of 27SLB-Private

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