WO2024138148A1

WO2024138148A1 - Systems and methods for cementing casing and sealing a hanger in a wellhead housing

Info

Publication number: WO2024138148A1
Application number: PCT/US2023/085735
Authority: WO
Inventors: Andrew Sanders; Kyle Sommerfeld; Leonard Vogel; Nicholas Ruff; Dennis Nguyen
Original assignee: Cameron International Corporation; Schlumberger Canada Limited; Cameron Technologies Limited
Priority date: 2022-12-22
Filing date: 2023-12-22
Publication date: 2024-06-27

Abstract

A wellhead includes a wellhead housing, a passage formed in or along the wellhead housing, and a hanger configured to support a casing. The wellhead also includes a seal assembly configured to provide an annular seal across an annular space between the hanger and the wellhead housing. In operation, a movable seal component or the seal assembly is configured to move relative to the passage to selectively enable a flow of fluid across the seal assembly via the passage.

Description

SYSTEMS AND METHODS FOR CEMENTING CASING AND SEALING A HANGER IN A WELLHEAD HOUSING

BACKGROUND

[0001] 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.

[0002] 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 of the earth, mineral extraction systems are often employed to access and extract the desired natural resource. The mineral extraction systems may be located onshore or offshore depending on the location of the desired natural resource. The mineral extraction systems generally 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

[0003] 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.

[0004] In certain embodiments, a wellhead includes a wellhead housing, a passage formed in or along the wellhead housing, and a hanger configured to support a casing. The wellhead also includes a seal assembly configured to provide an annular seal across an annular space between the hanger and the wellhead housing. A movable seal component or the seal assembly is configured to move relative to the passage to selectively enable a flow of fluid across the seal assembly via the passage.

[0005] In certain embodiments, a method of operating a wellhead includes running a hanger and a seal assembly into a wellhead housing. The method also includes routing a flow of fluid across the seal assembly via a passage formed in the wellhead housing during cementing operations with the hanger and the seal assembly in the wellhead housing. The method further includes, after the cementing operations, moving a movable component or the seal assembly relative to the wellhead housing to block the flow of fluid across the seal assembly and to seal an annular space between the hanger and the wellhead housing with the seal assembly

[0006] In certain embodiments, a wellhead includes a wellhead housing, a passage formed in the wellhead housing, and a hanger configured to support a casing. The wellhead also includes a seal assembly configured to move relative to the hanger between a first axial position and a second axial position within the wellhead housing. In the first axial position, the seal assembly enables a flow of fluid across the seal assembly via the passage. In the second axial position, the seal assembly blocks the flow of fluid across the seal assembly via the passage and provides an annular seal across an annular space between the hanger and the wellhead housing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] 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: [0008] FIG. 1 is a block diagram of a mineral extraction system, in accordance with an embodiment of the present disclosure;

[0009] FIG. 2 is a cross-sectional side view of an embodiment of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a passage and a piston configured to move within the passage to selectively seal the passage;

[0010] FIG. 3 is a cross-sectional side view of an embodiment of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a passage and a valve configured to selectively seal the passage;

[0011] FIG. 4 is cross-sectional side view of an embodiment of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a passage that is configured to receive a plug to selectively seal the passage;

[0012] FIG. 5 is a cross-sectional side view of an embodiment of the wellhead of FIG. 4, wherein the passage includes the plug to seal the passage;

[0013] FIG. 6 is a cross-sectional side view of an embodiment of a portion of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a passage and a seal assembly is configured to move within the wellhead housing to selectively seal the passage;

[0014] FIG. 7 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 6, wherein a lock ring is engaged to lock the wellhead housing and a hanger together while the seal assembly is positioned within the wellhead housing to enable a flow of fluid through the passage;

[0015] FIG. 8 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 6, wherein the seal assembly is positioned within the wellhead housing to block the flow of fluid through the passage;

[0016] FIG. 9 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 6, wherein a running tool is separated from the hanger; [0017] FIG. 10 is a cross-sectional side view of an embodiment of a portion of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a groove and a hanger with integral seals or a separate seal assembly is configured to move within the wellhead housing to selectively seal or isolate the groove from a hanger passage in a hanger;

[0018] FIG. 11 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 10, wherein the hanger with the integral seals or the separate seal assembly is positioned within the wellhead housing to block the flow of fluid from the groove to the hanger passage in the hanger;

[0019] FIG. 12 is a cross-sectional side view of an embodiment of a portion of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a passage and a hanger with integral seals is configured to move within the wellhead housing to selectively seal or isolate the passage from a hanger passage in a hanger;

[0020] FIG. 13 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 12, wherein the hanger with the integral seals is positioned within the wellhead housing to block the flow of fluid from the passage to the hanger passage in the hanger;

[0021] FIG. 14 is a cross-sectional side view of an embodiment of a portion of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a passage and a hanger with integral seals is configured to move within the wellhead housing to selectively seal or isolate the passage;

[0022] FIG. 15 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 14, wherein the hanger with the integral seals is positioned within the wellhead housing to block the flow of fluid through the passage;

[0023] FIG. 16 is a cross-sectional side view of an embodiment of a portion of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes a passage and a hanger with integral seals is configured to move within the wellhead housing to selectively seal or isolate the passage from a tool passage in a running tool;

[0024] FIG. 17 is a cross-sectional side view of an embodiment of a portion of the wellhead of FIG. 16, wherein one or more locks are provided about the wellhead housing;

[0025] FIG. 18 is a cross-sectional side view of an embodiment of a portion of the wellhead of FIG. 16, wherein the one or more locks are engaged with the hanger to lock the hanger within the wellhead housing;

[0026] FIG. 19 is a cross-sectional side view of an embodiment of a portion of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes housing protrusions and one or more grooves, and a hanger includes hanger protrusions and integral seals;

[0027] FIG. 20 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 19, wherein the housing protrusions and the hanger protrusions are circumferentially and axially offset with respect to one another, and the integral seals are positioned to enable a flow of fluid through the one or more grooves;

[0028] FIG. 21 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 19, wherein the housing protrusions and the hanger protrusions are circumferentially offset and axially aligned with respect to one another, and the integral seals are positioned axially above the one or more grooves to block the flow of fluid through the one or more grooves;

[0029] FIG. 22 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 19, wherein the housing protrusions and the hanger protrusions are circumferentially and axially aligned with respect to one another to lock the hanger within the wellhead housing, and the integral seals are positioned axially above the one or more grooves to block the flow of fluid through the one or more grooves; [0030] FIG. 23 is a cross-sectional side view of an embodiment of a portion of a wellhead that may be utilized in the mineral extraction system of FIG. 1 , wherein a wellhead housing includes an annular insert that defines a passage;

[0031] FIG. 24 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 23, wherein a seal assembly is positioned within the wellhead housing to enable a flow of fluid through the passage;

[0032] FIG. 25 is a cross-sectional side view of an embodiment of the portion of the wellhead of FIG. 23, wherein a seal assembly is positioned within the wellhead housing to block the flow of fluid through the passage; and

[0033] FIG. 26 is a flow diagram of an embodiment of a method of operating a wellhead to efficiently route fluid through a passage in or along a wellhead housing and seal a hanger in a wellhead housing.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0034] 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.

[0035] Certain embodiments of the present disclosure generally relate to systems and methods that support efficient casing installation operations. For example, certain embodiments of the present disclosure include a passage formed in or along a wellhead housing, and the passage is selectively sealed via a movable seal component, such as a piston, a valve, or a plug. In some cases, the movable seal component may be a seal assembly that seals an annular space between the wellhead housing and a hanger that supports the casing. During cementing operations, the movable seal component may be positioned to enable a flow of fluid through the passage formed in or along the wellhead housing. Then, after the cementing operations, the movable seal component may be positioned to block the flow of fluid through the passage formed in or along the wellhead housing (e.g., to seal the passage formed in or along the wellhead housing).

[0036] Advantageously, the systems and methods disclosed herein enable the seal assembly to run with the hanger into the wellhead housing (e.g., rather than running the hanger into the wellhead housing, then conducting cementing operations, and then running the seal assembly into the wellhead housing). Accordingly, the systems and methods disclosed herein may save time and associated costs during drilling operations.

[0037] With the foregoing in mind, FIG. 1 is a block diagram of an embodiment of a mineral extraction system 10. The mineral extraction system 10 may be 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 a wellhead 12 (e.g., annular wellhead) coupled to a mineral deposit 14 via a well 16. The well 16 may include a wellhead hub 18 (e.g., annular wellhead hub) and a wellbore 20. The wellhead hub 18 generally includes a large diameter hub disposed at an end of the wellbore 20 and is configured to connect the wellhead 12 to the wellbore 20. As will be appreciated, the wellbore 20 may contain elevated pressures. For example, the wellbore 20 may include pressures that exceed 10,000, 15,000, or even 20,000 pounds per square inch (psi). Accordingly, the mineral extraction system 10 may employ various mechanisms, such as seals, plugs, and valves, to control and regulate the well 16. [0038] In the illustrated embodiment, the mineral extraction system 10 includes a tree 22, a tubing spool 24, a casing spool 26, and a blowout preventer (BOP) 38. The tree 22 generally includes a variety of flow paths (e.g., bores), valves, fittings, and controls for operating the well 16. Further, the tree 22 may provide fluid communication with the well 16. For example, the tree 22 includes a tree bore 28 that provides for completion and workover procedures, such as the insertion of tools (e.g., a tool 40) into the well 16, the injection of various chemicals into the well 16, and so forth. Further, the natural resources extracted from the well 16 may be regulated and routed via the tree 22. For example, the tree 22 may be coupled to a flowline that is tied back to other components, such as a manifold.

[0039] As shown, the tubing spool 24 may provide a base for the tree 22 and includes a tubing spool bore 30 that connects (e.g., enables fluid communication between) the tree bore 28 and the well 16. As shown, the casing spool 26 may be positioned between the tubing spool 24 and the wellhead hub 18 and includes a casing spool bore 32 that connects (e.g., enables fluid communication between) the tree bore 28 and the well 16. Thus, the tubing spool bore 30 and the casing spool bore 32 may provide access to the wellbore 20 for various completion and workover procedures. The BOP 38 may consist of a variety of valves, fittings, and controls to block oil, gas, or other fluid from exiting the well 16 in the event of an unintentional release of pressure or an overpressure condition.

[0040] As shown, a tubing hanger 34 is positioned within the tubing spool 24. The tubing hanger 34 may be configured to support tubing (e.g., a tubing string) that is suspended in the wellbore 20 and/or to provide a path for control lines, hydraulic control fluid, chemical injections, and so forth. Additionally, as shown, a casing hanger 36 is positioned within the casing spool 26. The casing hanger 36 may be configured to support casing (e.g., a casing string) that is suspended in the wellbore 20. The tool 40 may be utilized to lower the tubing hanger 34 into the tubing spool 24 and/or the casing hanger 36 into the casing spool 26. [0041] As discussed in more detail herein, a passage may be formed in or along a wellhead housing (e.g., a portion of the casing spool 26), and the passage is selectively sealed via a movable component (e.g., a piston, a valve, a plug, a seal assembly that may be integral to or separate from the hanger 34, 36, thus the movable component may include the hanger 34, 36). During cementing operations, the movable component may be positioned to enable a flow of fluid through the passage formed in or along the wellhead housing. Thus, the flow of fluid may pass from below the hanger to above the hanger (e.g., relative to the wellbore) via the passage. Then, after the cementing operations, the movable component may be positioned to block the flow of fluid through the passage formed in or along the wellhead housing (e.g., to seal the passage formed in or along the wellhead housing). Thus, the flow of fluid may not pass from below the hanger to above the hanger via the passage. To facilitate discussion, the mineral extraction system 10, and the components therein, may be described with reference to an axial axis or direction 44, a radial axis or direction 46, and a circumferential axis or direction 48.

[0042] FIG. 2 is a cross-sectional side view of an embodiment of the wellhead 12. As shown, a wellhead housing 50 (e.g., a portion of a casing spool, such as a portion of the casing spool 36 of FIG. 1 ) includes a passage 52 and a piston 54 configured to move within the passage 52 to selectively seal the passage 52. A hanger 56 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ) is positioned in the wellhead housing 50 and suspends a casing 58 that extends into a wellbore. For example, the casing 58 may pass through an additional casing 60 and/or a conductor 62 to extend into the wellbore.

[0043] A seal assembly 64 (e.g., annular seal assembly) is positioned about the hanger 56. As shown, the seal assembly 64 may include annular seals supported in annular seal grooves formed in the hanger 56 (e.g., a body of the hanger 56; a single, solid body that includes the annular seal grooves for the annular seals and that supports the casing 58). In operation, a running tool may lower the hanger 56 with the casing 58 and the seal assembly 64 into the wellhead housing 50. The running tool may lower the hanger 56 until the hanger 56 reaches a landed position in which the hanger 56 is landed on the wellhead housing 50 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 56 relative to the wellhead housing 50 toward the wellbore). In the landed position, the seal assembly 64 may contact and seal against the wellhead housing 50. Thus, the seal assembly 64 seals an annular space between a radially outer surface of the hanger 56 and a radially inner surface of the wellhead housing 50, and the seal assembly 64 blocks fluid flow through the annular space.

[0044] In particular, the seal assembly 64 forms an annular seal at a first axial location within the wellhead housing 50. However, the passage 52 provides a bypass pathway for fluid flow between a second axial location within the wellhead housing 50 (e.g., below the first axial location relative to the wellbore) to a third axial location within the wellhead housing 50 (e.g., above the first axial location relative to the wellbore). For example, the passage 52 includes a first opening 66 (e.g., inlet) exposed to the annular space at the second axial location and a second opening 68 (e.g., outlet) exposed to the annular space (or, more generally, a bore 70 of the wellhead housing 50) at the third axial location. Further, the piston 54 is configured to move within the passage 52 (e.g., along the axial axis 44) to selectively seal the passage 52.

[0045] Thus, once the hanger 56 is in the landed position with the seal assembly 64 against the wellhead housing 50, cementing operations may commence to cement the casing 58 within the wellbore. The piston 54 is positioned to enable the fluid flow from the first opening 66 to the second opening 68 via the passage 52. In particular, the fluid flow of fluid may travel into the first opening 66, through the passage 52, and out the second opening 68 to return to the annular space (or the bore 70). Once the cementing operations are complete, the piston 54 is driven/moved to block the fluid flow from the first opening 66 to the second opening 68 via the passage 52. For example, the piston 54 may be driven/moved from a first piston position 72 shown in solid lines in FIG. 2 during the cementing operations to enable the fluid flow through the passage 52, to a second piston position 74 shown in dashed lines in FIG. 2 after the cementing operations to block the fluid flow through the passage 52.

[0046] The piston 54 may include seals 76 (e.g., annular seals) to seal against side walls of the passage 52. As shown, the passage 52 may include one or more additional openings 78, which may facilitate cementing operations for additional stages or levels of hangers and casings. In this way, the running tool may lower the hanger 56 with the casing 58 and the seal assembly 64 into the wellhead housing 50, and the seal assembly 64 may remain in the wellhead housing 50 (e.g., sealed against the wellhead housing 50) during the cementing operations. Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal between the hanger 56 and the wellhead housing 50 after the cementing operations.

[0047] It should be appreciated that the wellhead housing 50 may include multiple passages 52 distributed (e.g., spaced apart) about the circumferential axis 48 (e.g., at discrete locations about the circumferential axis 48). For example, the multiple passages 52 may include 2, 3, 4, or more passages 52 that each extend along the axial axis 44, that each include a respective piston 54, and that each include at least two respective openings (e.g., the openings 66, 68, 78). Advantageously, the multiple passages 52 may provide additional flow-by area (e.g., as compared to a signal passage 52) and/or dedicated passage(s) 52 for certain stages or levels of hangers and casings. For example, in some such cases, a first one of the multiple passages 52 may include two respective openings across a first axial range that corresponds to a first annulus (e.g., for a first stage or level of hanger and casing), while a second one of the multiple passages 52 may include two respective openings across a second axial range that corresponds to a second annulus (e.g., for a second stage or level of hanger and casing), wherein the first axial range is different from the second axial range (e.g., offset along the axial axis 44). Additionally, in some such cases, the first one of the multiple passages 52 may be at a first circumferential location, and the second one of the multiple passages 52 may be at a second circumferential location, wherein the first circumferential location is different from the second circumferential location (e.g., offset along the circumferential axis 48).

[0048] FIG. 3 is a cross-sectional side view of an embodiment of the wellhead 12, wherein a wellhead housing 80 includes a passage 82 and a valve 84 configured to selectively seal the passage 82. A hanger 86 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ) is positioned in the wellhead housing 80 and suspends a casing 88 that extends into a wellbore. For example, the casing 88 may pass through an additional casing 90 and/or a conductor 92 to extend into the wellbore.

[0049] A seal assembly 94 (e.g., annular seal assembly) is positioned about the hanger 86. As shown, the seal assembly 94 may include annular seals supported in annular seal grooves formed in the hanger 86 (e.g., a body of the hanger 86; a single, solid body that includes the annular seal grooves for the annular seals and that supports the casing 88). In operation, a running tool may lower the hanger 86 with the casing 88 and the seal assembly 94 into the wellhead housing 80. The running tool may lower the hanger 86 until the hanger 86 reaches a landed position in which the hanger 86 is landed on the wellhead housing 80 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 86 relative to the wellhead housing 80 toward the wellbore). In the landed position, the seal assembly 94 may contact and seal against the wellhead housing 80. Thus, the seal assembly 94 seals an annular space between a radially outer surface of the hanger 86 and a radially inner surface of the wellhead housing 80, and the seal assembly 94 blocks fluid flow through the annular space.

[0050] In particular, the seal assembly 94 forms an annular seal at a first axial location within the wellhead housing 80. However, the passage 82 provides a bypass pathway for fluid flow between a second axial location within the wellhead housing 80 (e.g., below the first axial location relative to the wellbore) to a third axial location within the wellhead housing 80 (e.g., above the first axial location relative to the wellbore). For example, the passage 82 includes a first opening 96 (e.g., inlet) exposed to the annular space at the second axial location and a second opening 98 (e.g., outlet) exposed to the annular space (or, more generally, a bore 100 of the wellhead housing 80) at the third axial location. Further, the valve 84 is configured to move within the passage 82 (e.g., along the radial axis 46) to selectively seal the passage 82 to block the fluid flow through the passage 82.

[0051] Thus, once the hanger 86 is in the landed position with the seal assembly 94 against the wellhead housing 80, cementing operations may commence to cement the casing 88 within the wellbore. The valve 84 is positioned to enable the fluid flow from the first opening 96 to the second opening 98 via the passage 82. In particular, the flow of fluid may travel into the first opening 96, through the passage 82, and out the second opening 98 to return to the bore 100. Once the cementing operations are complete, the valve 84 is actuated to block the fluid flow between the first opening 96 and the second opening 98 via the passage 82. For example, the valve 84 may be driven/moved from a first valve position or configuration in which a valve member of the valve 84 is withdrawn from the passage 82 to enable the fluid flow through the passage 82 to a second valve position or configuration in which the valve member of the valve 84 extends across the passage 82 to block the fluid flow through the passage 82 after the cementing operations. The valve 84 may include seals 106 (e.g., annular seals) to seal against walls of the passage 82 and/or the openings 96, 98. In this way, the running tool may lower the hanger 86 with the casing 88 and the seal assembly 94 into the wellhead housing 80, and the seal assembly 94 may remain in the wellhead housing 80 (e.g., sealed against the wellhead housing 80) during the cementing operations. Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 86 to the wellhead housing 80 after the cementing operations.

[0052] The valve 84 may include a check valve that enables fluid flow in one direction (e.g., only one direction; through the first opening 96 into to the passage 82). Upon completion of the cementing operations, a lock 110 (e.g., a threaded lock) may be engaged with the valve 84 to block any fluid flow across the valve 84 (e.g., to transition the valve 84 into a plug that blocks fluid flow through the first opening 96 into the passage 82). The valve 84 may also include another type of valve, such as an integrated valve (e.g., gate valve, ball valve).

[0053] As shown, the passage 82 may include one or more additional openings 108, which may facilitate cementing operations for additional stages or levels of hangers and casings. Additionally, one or more additional valves 84 may be positioned in the second opening 98 and the one or more additional openings 108 to selectively block fluid flow through the openings 98, 108 and the passage 82 during cementing operations for other stages or levels of casing.

[0054] It should be appreciated that the wellhead housing 80 may include multiple passages 82 distributed (e.g., spaced apart) about the circumferential axis 48 (e.g., at discrete locations about the circumferential axis 48). For example, the multiple passages 82 may include 2, 3, 4, or more passages 82 that each extend along the axial axis 44 and that each include at least two respective openings (e.g., the openings 96, 98, 108). Each of the at least two respective openings also include a respective valve 84. Advantageously, the multiple passages 82 may provide additional flow-by area (e.g., as compared to a signal passage 82) and/or dedicated passage(s) 82 for certain stages or levels of hangers and casings. For example, in some such cases, a first one of the multiple passages 82 may include two respective openings across a first axial range that corresponds to a first annulus (e.g., for a first stage or level of hanger and casing), while a second one of the multiple passages 82 may include two respective openings across a second axial range that corresponds to a second annulus (e.g., for a second stage or level of hanger and casing), wherein the first axial range is different from the second axial range (e.g., offset along the axial axis 44). Additionally, in some such cases, the first one of the multiple passages 82 may be at a first circumferential location, and the second one of the multiple passages 82 may be at a second circumferential location, wherein the first circumferential location is different from the second circumferential location (e.g., offset along the circumferential axis 48). [0055] In FIGS. 2 and 3, the components provide bypass passages formed in the wellhead housing to enable cement returns to flow around the hanger (e.g., via the wellhead housing). The components provide the bypass passage while the seal assemblies are in place to seal the annular space between the hanger and the wellhead housing. Multiple openings (e.g., inlets and outlets) may fluidly couple the bypass passages to the annular space and/or the bore of the wellhead housing to connect different casing annuli (e.g., facilitate running and cementing multiple stages or levels of casing). In such cases, the bypass passages may be sequentially sealed off or closed upon completion of cementing of each casing. A movable seal component, such as a piston or a valve, may be moved relative to the bypass passages to seal off or close the bypass passages.

[0056] FIGS. 4 and 5 are cross-sectional side views of an embodiment of the wellhead 12, wherein a wellhead housing 120 includes a passage 122 that is configured to receive a plug 124 configured to seal the passage 122. The plug 124 may be a valve remove [VR] or any other suitable type of plug. In particular, FIG. 4 shows the wellhead 12 with the plug 124 withdrawn or not positioned in the passage 122, and FIG. 5 shows the wellhead 12 with the plug 124 in the passage 122. A hanger 126 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ) is positioned in the wellhead housing 120 and suspends a casing 128 that extends into a wellbore. For example, the casing 128 may pass through an additional casing 130 and/or a conductor 132 to extend into the wellbore.

[0057] A seal assembly 134 (e.g., annular seal assembly with annular seal elements) is positioned about the hanger 126. As shown, the seal assembly 134 may include annular seals supported in annular seal grooves formed in the hanger 126 (e.g., a body of the hanger 126; a single, solid body that includes the annular seal grooves for the annular seals and that supports the casing 128). In operation, a running tool 135 may lower the hanger 126 with the casing 128 and the seal assembly 134 into the wellhead housing 120. The running tool 135 may lower the hanger 126 until the hanger 126 reaches a landed position in which the hanger 126 is landed on the wellhead housing 120 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 126 relative to the wellhead housing 120 toward the wellbore). In the landed position, the seal assembly 134 may contact and seal against the wellhead housing 120. Thus, the seal assembly 134 seals an annular space between a radially outer surface of the hanger 126 and a radially inner surface of the wellhead housing 120, and the seal assembly 134 blocks fluid flow through the annular space.

[0058] In particular, the seal assembly 134 forms an annular seal at a first axial location within the wellhead housing 120. However, the passage 122 provides a bypass pathway for fluid flow between a second axial location within the wellhead housing 120 (e.g., below the first axial location relative to the wellbore) to a third axial location within the wellhead housing 120 (e.g., above the first axial location relative to the wellbore). For example, the passage 122 includes a first opening 136 (e.g., inlet) exposed to the annular space at the second axial location and a second opening 138 (e.g., outlet) exposed to the annular space (or, more generally, a bore 140 of the wellhead housing 120) at the third axial location. Further, the plug 124 is configured to be inserted into the passage 122 (e.g., along the radial axis 46) to selectively seal the passage 122 to block the fluid flow through the passage 122. The plug 124 may be inserted through an access port 125 at a radially outer surface of the wellhead housing 120.

[0059] Thus, once the hanger 126 is in the landed position with the seal assembly 134 against the wellhead housing 120, cementing operations may commence to cement the casing 128 within the wellbore. The plug 124 is withdrawn or not positioned in the passage 122 to enable the fluid flow from the first opening 136 to the second opening 138 via the passage 122. In particular, the flow of fluid may travel into the first opening 136, through the passage 122, and out the second opening 138 to return to the bore 140. Once the cementing operations are complete, the plug 124 is inserted through the access port 125 to block the fluid flow between the first opening 136 and the second opening 138 via the passage 122. For example, the plug 124 may be driven/moved from a first plug position or configuration in which the plug 124 is withdrawn from the passage 122 to enable the fluid flow through the passage 122, to a second plug position or configuration in which the plug 124 extends across the passage 122 to block the fluid flow through the passage 122 after the cementing operations. The plug 124 may include seals 146 (e.g., annular seals) to seal against walls of the passage 122 and/or the second opening 138. In this way, the running tool 135 may lower the hanger 126 with the casing 128 and the seal assembly 134 into the wellhead housing 120, and the seal assembly 134 may remain in the wellhead housing 120 (e.g., sealed against the wellhead housing 120) during the cementing operations. Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 126 to the wellhead housing 120 after the cementing operations.

[0060] As shown in FIG. 5, once the cementing operations are complete, the running tool 135 may be separated from the hanger 126 and withdrawn from the wellhead 12. Further, other structures, such as an additional hanger (e.g., a tubing hanger, such as the tubing hanger 34 of FIG. 1 ), may then be positioned in the wellhead housing 120 to proceed with installation and setup of the wellhead 12.

[0061] FIGS. 6-9 are cross-sectional side views of an embodiment of a portion of the wellhead 12, wherein a wellhead housing 150 includes a passage 152. Additionally, a seal assembly 154 (e.g., annular seal assembly) is positioned between the wellhead housing 150 and an a hanger 156 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ). The seal assembly 154 is configured to move to selectively block fluid flow through the passage 152. The hanger 156 is positioned in the wellhead housing 150 and suspends a casing 158 that extends into a wellbore. For example, the casing 158 may pass through an additional casing and/or a conductor to extend into the wellbore.

[0062] As shown, a running tool 155 may lower the hanger 156 with the casing 158, the seal assembly 154, and a lock ring 157 (e.g., annular lock ring; c- ring) into the wellhead housing 150. The running tool 155 may lower the hanger 156 until the hanger 156 reaches a landed position in which the hanger 156 is landed on the wellhead housing 150 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 156 relative to the wellhead housing 150 toward the wellbore). In the landed position, the seal assembly 154 may contact and seal against both the wellhead housing 150 and the hanger 156. For example, the seal assembly 154 may include an annular ring 159 (e.g., ring body) that supports first annular seal elements on a radially inner surface that seal against a radially outer surface of the hanger 156 and second annular seal elements on a radially outer surface that seal against a radially inner surface of the housing 150. Thus, the seal assembly 154 seals an annular space between the radially outer surface of the hanger 156 and the radially inner surface of the wellhead housing 150, and the seal assembly 154 blocks fluid flow through the annular space. Additionally, in the landed position, the lock ring 157 may axially align with a corresponding recess 161 (e.g., annular recess or groove) in the radially inner surface of the wellhead housing 150.

[0063] Once the hanger 156 is in the landed position, the running tool 155 may be rotated (e.g., unthreaded) to cause the annular ring 159 with the seal assembly 154 to move axially (e.g., away from the wellbore) relative to the hanger 156 and the lock ring 157 supported by the hanger 156, as well as relative to the wellhead housing 150. The running tool 155 may be rotated until the annular ring 159 of the seal assembly 154 separates from the lock ring 157, which enables the lock ring 157 to expand radially outwardly to engage the corresponding recess 161 to lock the hanger 156 within the wellhead housing 150 (e.g., block axial movement of the hanger 156 relative to the wellhead housing 150).

[0064] However, to facilitate cementing operations, the running tool 155 is only partially rotated so that the seal assembly 154 remains positioned axially between a first opening 166 and a second opening 168 of the passage 152. Thus, the passage 152 provides a bypass pathway for fluid flow between a second axial location within the wellhead housing 150 (e.g., below the first axial location relative to the wellbore) to a third axial location within the wellhead housing 150 (e.g., above the first axial location relative to the wellbore via the first opening 166 (e.g., inlet) and the second opening 168 (e.g., outlet) that fluidly couple to the passage 152. The first opening 166 is exposed to the annular space at the second axial location and the second opening 168 (e.g., outlet) exposed to the annular space (or, more generally, a bore 170 of the wellhead housing 150) at the third axial location.

[0065] As shown in FIG. 7, once the hanger 156 is in the landed position and/or a locked position in the wellhead housing 150, cementing operations may commence to cement the casing 158 within the wellbore. The seal assembly 154 is positioned axially between the first opening 166 and the second opening 168 to enable the fluid flow through the passage 152. The flow of fluid may travel into the first opening 166, through the passage 152, and out the second opening 168 to return to the bore 170.

[0066] As shown in FIG. 8, once the cementing operations are complete, the running tool 155 is rotated (e.g. unthreaded) until the seal assembly 154 is positioned axially above the second opening 168 (e.g., relative to the wellbore), which blocks the fluid flow through the passage 152 and/or blocks the fluid flow from traveling axially above the seal assembly 154 (e.g., relative to the wellbore) to thereby protect equipment axially above the seal assembly 154, for example. As shown in FIG. 9, the running tool 155 may continue to be rotated until the running tool 55 separates from the hanger 156 and the annular ring 159 of the seal assembly 154.

[0067] In this way, the running tool 155 may lower the hanger 156 with the casing 158, the seal assembly 154, and the lock ring 157 into the wellhead housing 150, and the seal assembly 154 may remain in the wellhead housing 150 during the cementing operations. However, the seal assembly 154 may move relative to the wellhead housing 150 after the cementing operations to seal the annular space between the hanger 156 and the wellhead housing 150, as well as the passage 152. In this way, the seal assembly 154 essentially operates as a movable component that selectively seals the passage 152. Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 156 to the wellhead housing 150 after the cementing operations.

[0068] The seal assembly 154, the running tool 155, and the hanger 156 may have any suitable interfaces that enable the operations and techniques described herein. For example, the running tool 155 may be threadably coupled to the hanger 156 and may also be coupled to the seal assembly 154 via an additional lock ring that engages an additional corresponding lock groove of the annular ring 159 of the seal assembly 154. The seal assembly 154 may be blocked from rotating with the running tool 155, such that the rotation of the running tool 155 (e.g., to unthread the running tool 155 from the hanger 156) drives axial movement of the seal assembly 154 (e.g., without rotation) relative to the wellhead housing and the hanger 156.

[0069] FIGS. 10 and 11 are cross-sectional side views of an embodiment of a portion of the wellhead 12, wherein a wellhead housing 200 includes a groove 202 and a seal assembly 204 is configured to move within the wellhead housing 200 to selectively seal the groove 202 from a hanger passage 206 in a hanger 208. As shown, the seal assembly 204 may include annular seals supported in annular seal grooves formed in the hanger 208 (e.g., a body of the hanger 208; a single, solid body that includes the annular seal grooves for the annular seals and that supports a casing 226).

[0070] In FIG. 10, the seal assembly 204 is axially aligned with the groove 202 to enable fluid flow to travel axially across the seal assembly 204 from a first axial position below the seal assembly 204 (e.g., relative to a wellbore; an annular space between the hanger 208 and the wellhead housing 200) to a second axial position above the seal assembly 204 (e.g., relative to the wellbore; to enter the hanger passage 206). In particular, the fluid flow may travel axially across the seal assembly 204 and into an opening 210 (e.g., inlet) of the hanger passage 206 of the hanger 208. As shown, the groove 202 provides an enlarged inner diameter of the wellhead housing 200 (e.g., relative to portions of the wellhead housing 200 above and/or below the groove 202), such that the seal assembly 204 (e.g., annular seals of the seal assembly 204) do not contact and do not seal against a radially inner surface of the wellhead housing 200 when the seal assembly 204 is axially aligned with the groove 202.

[0071] Various features of the wellhead housing 200 and the hanger 208 may facilitate efficient running, cementing, and sealing operations. For example, a running tool 212 may run the hanger 208 with the seal assembly 204 into the wellhead housing 200 until the hanger 208 reaches a landed position in which the hanger 208 is landed on the wellhead housing 200 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 208 relative to the wellhead housing 200 toward the wellbore). In the embodiment shown in FIGS. 10 and 11 , the hanger 208 is landed on the wellhead housing 200 upon contact between a hanger surface 214 and a housing surface 216 of the wellhead housing 200.

[0072] In response to detection of the hanger 208 being in the landed position (e.g., slack off weight), the running tool 212 moves the hanger 208 axially (e.g., away from the wellbore; raises the hanger 208) to align a first lock ring 218 with a lock ring groove 220 in the wellhead housing 200. An actuation sleeve 222 (e.g., a hydraulic actuation sleeve) of the running tool 212 may be driven axially (e.g., toward the wellbore) to insert radially between the hanger 208 and the first lock ring 218, which drives the first lock ring 218 radially outwardly away from the hanger 208 toward the lock ring groove 220 in the wellhead housing 200. Then, the running tool 212 again moves the hanger 208 axially (e.g., toward the wellbore; lowers the hanger 208) until the first lock ring 218 contacts a lower shoulder 224 of the lock ring groove 220. In this position or configuration, which is illustrated in FIG. 10, the seal assembly 204 is axially aligned with the groove 202 formed in the wellhead housing 200 and the groove 202 is able to provide a bypass for fluid flow across the seal assembly 204. Accordingly, in this position or configuration, cementing operations may be carried out to cement the casing 226 supported by the hanger 208 in the wellbore. [0073] Once the cementing operations are complete, the running tool 212 may raise the hanger 208 until the first lock ring 218 contacts an upper shoulder 228 of the lock ring groove 220. In this position or configuration, which is illustrated in FIG. 11 , the seal assembly 204 is axially offset (e.g., axially above, relative to the wellbore) from the groove 202 formed in the wellhead housing 200 and the groove 202 is not able to provide the bypass for fluid flow across the seal assembly 204. Accordingly, in this position or configuration, the seal assembly 204 blocks the fluid flow into the hanger passage 206 and seals an annular space between the hanger 208 and the wellhead housing 200 to thereby protect equipment positioned axially above the seal assembly 204, for example.

[0074] Further, as shown in FIG. 11 , the actuation sleeve 222 of the running tool 212 may be driven axially (e.g., toward the wellbore) to insert radially between the hanger 208 and a second lock ring 230, which drives the second lock ring 230 radially outwardly away from the hanger 208 into the lock ring groove 220 in the wellhead housing 200. Thus, the first lock ring 218 and the second lock ring 230 are both positioned within the lock ring groove 220 (e.g., stacked on top of one another along the axial axis 44), and contact between the first lock ring 218 and the upper shoulder 228 of the lock ring groove 220 and contact between the second lock ring 230 and the lower shoulder 224 of the lock ring groove 220 block axial movement of the hanger 208 with the seal assembly 204 and the lock rings 218, 230 (e.g., a two-piece lock ring) relative to the wellhead housing 200.

[0075] In this way, the running tool 212 may lower the hanger 208 with the casing 226, the seal assembly 204, and the lock rings 218, 230 into the wellhead housing 200, and the seal assembly 204 may remain in the wellhead housing 200 (e.g., aligned with the groove 202; not sealed against the wellhead housing 200) during the cementing operations. However, the hanger 208 with the casing 226, the seal assembly 204, and the lock rings 218, 230 may move relative to the wellhead housing 200 after the cementing operations to seal the annular space between the hanger 208 and the wellhead housing 200. In this way, the hanger 208 with the seal assembly 204 may essentially operate as a movable component that selectively seals the annular space (e.g., selectively exposes the groove 202 to the hanger passage 206 or seals the groove 202 from the hanger passage 206; the groove 202 operates as a bypass passage). Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 208 to the wellhead housing 200 after the cementing operations.

[0076] FIGS. 12 and 13 are cross-sectional side views of an embodiment of a portion of the wellhead 12, wherein a wellhead housing 250 includes a passage 252. Additionally, a seal assembly 254 (e.g., annular seal assembly) is configured to move within the wellhead housing 250 to selectively seal the passage 252 from a hanger passage 256 in a hanger 258 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ). As shown, the seal assembly 254 is supported in the hanger 258, which suspends a casing 260 that extends into a wellbore. For example, the casing 260 may pass through an additional casing and/or a conductor to extend into the wellbore.

[0077] As shown in an inset provided in FIG. 12, the seal assembly 254 includes annular seals 262 supported in annular seal grooves 264 that are formed in the hanger 258 (e.g., a body of the hanger 258; a single, solid body that includes the annular seal grooves 264 for the annular seals 262 and that supports the casing 260; the seal assembly 254 is part of or integral with the hanger 258). Further, the seal assembly 254 may include or work in conjunction with an annular wiper seal 266 supported in an additional annular groove 268 that is formed in the hanger 258.

[0078] In FIG. 12, the seal assembly 264 is axially aligned with the passage 252 to enable fluid flow to travel axially across the seal assembly 264 from a first axial position below the seal assembly 264 (e.g., relative to a wellbore; an annular space between the hanger 258 and the wellhead housing 250) to a second axial position above the seal assembly 264 (e.g., relative to the wellbore; to enter the hanger passage 256). In particular, the fluid flow may travel axially across the seal assembly 264 and into an opening 270 (e.g., inlet) of the hanger passage 256 of the hanger 258.

[0079] Various features of the wellhead housing 250 and the hanger 258 may facilitate efficient running, cementing, and sealing operations. For example, a running tool 272 may run the hanger 258 with the seal assembly 264 into the wellhead housing 250 until the hanger 258 reaches a landed position in which the hanger 258 is landed on the wellhead housing 250 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 258 relative to the wellhead housing 250 toward the wellbore). In the embodiment shown in FIGS. 12 and 13, and with reference to the inset provided in FIG. 12, the hanger 258 is landed on the wellhead housing 250 upon contact between a hanger surface 274 of the hanger 258 and a housing surface 276 of the wellhead housing 250. With the hanger 258 in the landed position, the seal assembly 264 is axially aligned with the passage 252 to enable the fluid flow around the seal assembly 264 through the passage 252.

[0080] In response to detection of the hanger 258 being in the landed position (e.g., slack off weight), a retainer 280 (e.g., one or more temporary locks, such as one or more hold down screws) may be driven (e.g., via an actuator; via manual operation by an operator) radially inwardly through the wellhead housing 250 (or through a blowout preventer adapter that is coupled to the wellhead housing 250). It should be appreciated that the retainer 280 may have any suitable form, such as one or more retainer screws that are inserted into respective openings 282 (e.g., threaded openings) that are spaced apart or distributed circumferentially about the wellhead housing 250. In certain embodiments, the retainer 280 may contact and engage a tool surface 284 of the running tool 272 to block axial movement of the running tool 272 (and the hanger 258 coupled thereto) relative to the wellhead housing 250. Further, as described herein, the retainer 280 may block withdrawal of the hanger 258 from the wellhead housing 250 (e.g., at least a portion of the hanger 258 with the seal assembly 264 is maintained between the housing surface 276 of the wellhead housing 250 and the retainer 280 along the axial axis 44). [0081] With the hanger 258 in the landed position as illustrated in FIG. 12, the seal assembly 264 is axially aligned with the passage 252 to enable fluid flow axially across the seal assembly 264 and into the opening 270 of the hanger passage 256 of the hanger 258. Thus, the passage 252 and the hanger passage 256 are able to provide a bypass for fluid flow across the seal assembly 264. Accordingly, in this position or configuration, cementing operations may be carried out to cement the casing 260 supported by the hanger 258 in the wellbore.

[0082] Once the cementing operations are complete, the running tool 272 may raise the hanger 258 until the retainer 280 contacts an upper shoulder 286 of the hanger 258. In this position or configuration, which is illustrated in FIG. 13, the seal assembly 264 is axially offset (e.g., axially above, relative to the wellbore) from the passage 252 formed in the wellhead housing 250 and the passage 252 is not able to provide the bypass for fluid flow across the seal assembly 264. Accordingly, in this position or configuration, the seal assembly 264 blocks the fluid flow into the hanger passage 256 and seals an annular space between the hanger 258 and the wellhead housing 250 to thereby protect equipment positioned axially above the seal assembly 264, for example.

[0083] Further, as shown in FIGS. 12 and 13, a lock ring 288 (e.g., segmented lock ring; one or more locks, such as one or more load segments) may be driven (e.g., via an actuator; via manual operation by an operator) radially inwardly relative to the wellhead housing 250 to adjust the hanger 258 to a locked position in the wellhead housing 250. It should be appreciated that the lock ring 288 may have any suitable form, such as a segmented lock ring with one or more locks (e.g., load segments) that are inserted into respective openings 290 (e.g., threaded openings) that are spaced apart or distributed circumferentially about the wellhead housing 250. As shown in FIG. 13, the lock ring 288 may contact and engage a groove 292 of the hanger 258 (e.g., in a radially outer surface of the hanger 258) to block axial movement of the hanger 258 relative to the wellhead housing 250. It should be appreciated that the running tool 272 may then be separated from the hanger 258 (e.g., via rotation to unthread the running tool 272 from the hanger 258). Further, the retainer 280 may also be withdrawn or moved radially outwardly from the wellhead housing 250.

[0084] In this way, the running tool 272 may lower the hanger 258 with the casing 260 and the seal assembly 264 into the wellhead housing 250, and the seal assembly 264 may remain in the wellhead housing 250 (e.g., aligned with the passage 252 to open the passage 252 to fluid flow) during the cementing operations. However, the hanger 258 with the casing 260 and the seal assembly 264 may move relative to the wellhead housing 250 after the cementing operations to seal the annular space between the hanger 258 and the wellhead housing 250. In this way, the hanger 258 with the seal assembly 264 may essentially operate as a movable component that selectively seals the annular space (e.g., selectively exposes the passage 252 to the hanger passage 256 or seals the passage 252 from the hanger passage 256; the passage 252 operates as a bypass passage). Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 258 to the wellhead housing 250 after the cementing operations.

[0085] Advantageously, with reference to the inset provided in FIG. 12, the annular seals 262 are axially aligned with and contact a first portion 294 of a radially-inner surface of the wellhead housing 250 during the cementing operations. This placement and configuration block contact between the fluid flow that travels through the passage 252 and the annular seals 262, thereby protecting the annular seals 262 from wear, abrasion, and so forth. Additionally, with reference to the inset provided in FIG. 12 and also with reference to FIG. 13, the annular wiper seal 266 may slide along and clean (e.g., wipe) a second portion 296 of the radially-inner surface of the wellhead housing 250 prior to contact between the annular seals 262 and the second portion 296 of the radially-inner surface of the wellhead housing 250. In this way, the annular wiper seal 266 may also protect the annular seals 262 from wear, abrasion, and so forth. It should be appreciated that the seal assembly 254 may have any suitable number of annular seals 262, such as 1 , 2, 3, 4, or more stacked or spaced apart along the axial axis 44. Additionally, it should be appreciated that any suitable number of annular wiper seals 266 may be provided, such as 1 , 2, 3, 4, or more stacked or spaced apart along the axial axis 44.

[0086] FIGS. 14 and 15 are cross-sectional side views of an embodiment of a portion of the wellhead 12, wherein a wellhead housing 300 includes a passage 302. Additionally, a seal assembly 304 (e.g., annular seal assembly) is configured to move within the wellhead housing 300 to selectively seal the passage 302. As shown, the seal assembly 304 is supported in a hanger 308 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ), which suspends a casing 310 that extends into a wellbore. For example, the casing 310 may pass through an additional casing and/or a conductor to extend into the wellbore.

[0087] As shown in an inset provided in FIG. 14, the seal assembly 304 includes annular seals 312 supported in annular seal grooves 264 that are formed in the hanger 258 (e.g., a body of the hanger 258; a single, solid body that includes the annular seal grooves 314 for the annular seals 312 and that supports the casing 310; the seal assembly 304 is part of or integral with the hanger 308). Further, the seal assembly 304 may include or work in conjunction with an annular wiper seal 316 supported in an additional annular groove 318 that is formed in the hanger 308. In FIG. 14, the seal assembly 304 is axially aligned with the passage 302 to enable fluid flow to travel axially across the seal assembly 304 from a first axial position below the seal assembly 304 (e.g., relative to a wellbore; an annular space between the hanger 308 and the wellhead housing 300) to a second axial position above the seal assembly 304 (e.g., relative to the wellbore).

[0088] Various features of the wellhead housing 300 and the hanger 308 may facilitate efficient running, cementing, and sealing operations. For example, a running tool 322 may run the hanger 308 with the seal assembly 304 into the wellhead housing 300 until the hanger 308 reaches a landed position in which the hanger 308 is landed on the wellhead housing 300 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 308 relative to the wellhead housing 300 toward the wellbore). In the embodiment shown in FIGS. 14 and 15, and with reference to the inset provided in FIG. 14, the hanger 308 is landed on the wellhead housing 300 upon contact between a hanger surface 324 of the hanger 308 and a housing surface 326 of the wellhead housing 300. With the hanger 308 in the landed position, the seal assembly 304 is axially aligned with the passage 302 to enable the fluid flow axially across the seal assembly 304.

[0089] In response to detection of the hanger 308 being in the landed position (e.g., slack off weight), a retainer 330 (e.g., one or more temporary locks, such as one or more hold down screws) may be driven (e.g., via an actuator; via manual operation by an operator) radially inwardly through the wellhead housing 300 (or through a blowout preventer adapter that is coupled to the wellhead housing 300). It should be appreciated that the retainer 330 may have any suitable form, such as one or more retainer screws that are inserted into respective openings 332 (e.g., threaded openings) that are spaced apart or distributed circumferentially about the wellhead housing 300. Further, as described herein, the retainer 330 may block withdrawal of the hanger 308 from the wellhead housing 300 (e.g., at least a portion of the hanger 308 with the seal assembly 304 is maintained between the housing surface 326 of the wellhead housing 300 and the retainer 330 along the axial axis 44).

[0090] With the hanger 308 in the landed position as illustrated in FIG. 14, the seal assembly 304 is axially aligned with the passage 302 to enable fluid flow axially across the seal assembly 304. Thus, the passage 302 is able to provide a bypass for fluid flow across the seal assembly 304. Accordingly, in this position or configuration, cementing operations may be carried out to cement the casing 310 supported by the hanger 308 in the wellbore.

[0091] Once the cementing operations are complete, the running tool 322 may raise the hanger 308 until the retainer 330 contacts an upper shoulder 336 of the hanger 258 (or a portion of the running tool 322 that is coupled to the hanger 258). In this position or configuration, which is illustrated in FIG. 15, the seal assembly 304 is axially offset (e.g., axially above, relative to the wellbore) from the passage 302 formed in the wellhead housing 300 and the passage 302 is not able to provide the bypass for fluid flow across the seal assembly 304. Accordingly, in this position or configuration, the seal assembly 304 blocks the fluid flow and seals an annular space between the hanger 308 and the wellhead housing 300 to thereby protect equipment positioned axially above the seal assembly 304, for example.

[0092] While a lock ring is not illustrated in FIGS. 14 and 15, it should be appreciated that any suitable lock ring (e.g., segmented lock ring; one or more locks, such as one or more load segments) may be driven (e.g., via an actuator; via manual operation by an operator) radially inwardly relative to the wellhead housing 300 to adjust the hanger 308 to a locked position in the wellhead housing 300. For example, the lock ring may contact and engage a groove of the hanger 308 (e.g., in a radially outer surface of the hanger 308) to block axial movement of the hanger 308 relative to the wellhead housing 300. Further, when engaged with the hanger 308, the lock ring blocks axial movement of the hanger 308 relative to the wellhead housing 300. It should be appreciated that the running tool 322 may then be separated from the hanger 308 (e.g., via rotation to unthread the running tool 322 from the hanger 308). Further, the retainer 330 may also be withdrawn or moved radially outwardly from the wellhead housing 300.

[0093] In this way, the running tool 322 may lower the hanger 308 with the casing 310 and the seal assembly 304 into the wellhead housing 300, and the seal assembly 304 may remain in the wellhead housing 300 (e.g., aligned with the passage 302 to open the passage 302 to fluid flow) during the cementing operations. However, the hanger 308 with the casing 310 and the seal assembly 304 may move relative to the wellhead housing 300 after the cementing operations to seal the annular space between the hanger 308 and the wellhead housing 300. In this way, the hanger 308 with the seal assembly 304 may essentially operate as a movable component that selectively seals the annular space (e.g., selectively exposes the passage 302 or seals the passage 302; the passage 302 operates as a bypass passage). Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 308 to the wellhead housing 300 after the cementing operations.

[0094] Advantageously, with reference to the inset provided in FIG. 14, the annular seals 312 are axially aligned with and contact a first portion 344 of a radially-inner surface of the wellhead housing 300 during the cementing operations. This placement and configuration block contact between the fluid flow that travels through the passage 302 and the annular seals 312, thereby protecting the annular seals 312 from wear, abrasion, and so forth. Additionally, with reference to the inset provided in FIG. 14 and also with reference to FIG. 15, the annular wiper seal 316 may slide along and clean (e.g., wipe) a second portion 346 of the radially-inner surface of the wellhead housing 300 prior to contact between the annular seals 312 and the second portion 346 of the radially-inner surface of the wellhead housing 300. In this way, the annular wiper seal 316 may also protect the annular seals 312 from wear, abrasion, and so forth. It should be appreciated that the seal assembly 304 may have any suitable number of annular seals 312, such as 1 , 2, 3, 4, or more stacked or spaced apart along the axial axis 44. Additionally, it should be appreciated that any suitable number of annular wiper seals 316 may be provided, such as 1 , 2, 3, 4, or more stacked or spaced apart along the axial axis 44.

[0095] FIGS. 16-18 are cross-sectional side views of an embodiment of a portion of the wellhead 12, wherein a wellhead housing 350 includes a passage 352. Additionally, a seal assembly 354 (e.g., annular seal assembly) is configured to move within the wellhead housing 350 to selectively seal the passage 352. As shown, the seal assembly 354 is supported in a hanger 358 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ), which suspends a casing 360 that extends into a wellbore. For example, the casing 360 may pass through an additional casing and/or a conductor to extend into the wellbore.

[0096] As shown in an inset provided in FIG. 16, the seal assembly 354 includes annular seals 362 supported in annular seal grooves 364 that are formed in the hanger 358 (e.g., a body of the hanger 358; a single, solid body that includes the annular seal grooves 364 for the annular seals 362 and that supports the casing 360; the seal assembly 354 is part of or integral with the hanger 358). Further, the seal assembly 354 may include or work in conjunction with an annular wiper seal 366 supported in an additional annular groove 368 that is formed in the hanger 358. In FIG. 16, the seal assembly 354 is axially aligned with the passage 352 to enable fluid flow to travel axially across the seal assembly 354 from a first axial position below the seal assembly 354 (e.g., relative to a wellbore; an annular space between the hanger 358 and the wellhead housing 350) to a second axial position above the seal assembly 354 (e.g., relative to the wellbore).

[0097] Various features of the wellhead housing 350 and the hanger 358 may facilitate efficient running, cementing, and sealing operations. For example, a running tool 372 may run the hanger 358 with the seal assembly 354 into the wellhead housing 350 until the hanger 358 reaches a landed position in which the hanger 358 is landed on the wellhead housing 350 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 358 relative to the wellhead housing 350 toward the wellbore). In the embodiment shown in FIGS. 16-18, and with reference to the inset provided in FIG. 16, the hanger 358 is landed on the wellhead housing 350 upon contact between a hanger surface 374 of the hanger 358 and a housing surface 376 of the wellhead housing 350. With the hanger 358 in the landed position, the seal assembly 354 is axially aligned with the passage 352 to enable the fluid flow axially across the seal assembly 354.

[0098] In response to detection of the hanger 358 being in the landed position (e.g., slack off weight), a retainer 380 (e.g., one or more temporary locks, such as one or more hold down screws) may be driven (e.g., via an actuator; via manual operation by an operator) radially inwardly through the wellhead housing 350 (or through a blowout preventer adapter that is coupled to the wellhead housing 350). It should be appreciated that the retainer 380 may have any suitable form, such as one or more retainer screws that are inserted into respective openings 382 (e.g., threaded openings) that are spaced apart or distributed circumferentially about the wellhead housing 350. Further, as described herein, the retainer 380 may block withdrawal of the hanger 358 from the wellhead housing 350 (e.g., at least a portion of the hanger 358 with the seal assembly 354 is maintained between the housing surface 376 of the wellhead housing 350 and the retainer 380 along the axial axis 44).

[0099] With the hanger 358 in the landed position as illustrated in FIG. 16, the seal assembly 354 is axially aligned with the passage 352 to enable fluid flow axially across the seal assembly 354. Thus, the passage 352 is able to provide a bypass for fluid flow across the seal assembly 354. Accordingly, in this position or configuration, cementing operations may be carried out to cement the casing 360 supported by the hanger 358 in the wellbore.

[00100] Once the cementing operations are complete, the running tool 372 may raise the hanger 358 until the retainer 380 contacts an upper shoulder 386 of the hanger 358 (or a portion of the running tool 372 that is coupled to the hanger 358). In this position or configuration, which is illustrated in FIG. 18, the seal assembly 354 is axially offset (e.g., axially above, relative to the wellbore) from the passage 352 formed in the wellhead housing 350 and the passage 352 is not able to provide the bypass for fluid flow across the seal assembly 354. Accordingly, in this position or configuration, the seal assembly 354 blocks the fluid flow and seals an annular space between the hanger 358 and the wellhead housing 350 to thereby protect equipment positioned axially above the seal assembly 354, for example.

[00101] Further, as shown in FIGS. 16-18, a lock ring 388 (e.g., segmented lock ring) may be driven (e.g., via an actuator; via manual operation by an operator) radially inwardly relative to the wellhead housing 350 to adjust the hanger 358 to a locked position in the wellhead housing 350. It should be appreciated that the lock ring 388 may have any suitable form, such as a segmented lock ring with one or more locks 390 (e.g., load segments).

[00102] Additional features that may be included in the lock ring 388 are described herein with reference to FIG. 17. As shown, the one or more locks 390 may include multiple locks that are inserted into respective openings 392 (e.g., threaded openings) that are spaced apart or distributed circumferentially about the wellhead housing 350. In certain embodiments, each lock 390 may include a retaining pin 400, a dowl pin 402, a push rod 404, a gland 406, and one or more seals 408 (e.g., o-ring seals). It should be appreciated that one or more additional seals 410 (e.g., o-ring seals; compression seals) may be provided about the push rod 404. As shown, the retaining pin 400 contacts and engages the lock 390. In operation, rotation of the gland 406 may cause the gland 406 to travel radially within the respective opening 392 via corresponding threads 412 (e.g., a threaded interface). In this way, rotation of the gland 406 in a first rotational direction may cause the gland 406, and the components coupled thereto, to travel radially inwardly relative to the respective opening 392. Further, rotation of the gland 406 in a second rotational direction (e.g., opposite the first rotational direction) may cause the gland 406, and the components coupled thereto, to travel radially outwardly relative to the respective opening 392.

[00103] Thus, as shown in FIGS. 16 and 17, each of the one or more locks 390 may be withdrawn within its respective opening 392 as the running tool 372 lowers the hanger 358 to the landed position within the wellhead housing 350. However, with reference to FIG. 18, each of the one or more locks 390 may be extended from its respective opening 392 to contact and engage a respective groove 414 of the hanger 358 (e.g., in a radially outer surface of the hanger 358) to block axial movement of the hanger 358 relative to the wellhead housing 350. It should be appreciated that the running tool 372 may then be separated from the hanger 358 (e.g., via rotation to unthread the running tool 372 from the hanger 358). Further, the retainer 380 may also be withdrawn or moved radially outwardly from the wellhead housing 350.

[00104] In this way, the running tool 372 may lower the hanger 358 with the casing 360 and the seal assembly 354 into the wellhead housing 350, and the seal assembly 354 may remain in the wellhead housing 350 (e.g., aligned with the passage 352 to open the passage 352 to fluid flow) during the cementing operations. However, the hanger 358 with the casing 360 and the seal assembly 354 may move relative to the wellhead housing 350 after the cementing operations to seal the annular space between the hanger 358 and the wellhead housing 350. In this way, the hanger 358 with the seal assembly 354 may essentially operate as a movable component that selectively seals the annular space (e.g., selectively exposes the passage 352 or seals the passage 352; the passage 352 operates as a bypass passage). Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 358 to the wellhead housing 350 after the cementing operations.

[00105] Advantageously, with reference to the inset provided in FIG. 16, the annular seals 362 are axially aligned with and contact a first portion 416 of a radially-inner surface of the wellhead housing 350 during the cementing operations. This placement and configuration block contact between the fluid flow that travels through the passage 352 and the annular seals 362, thereby protecting the annular seals 362 from wear, abrasion, and so forth. Additionally, with reference to the inset provided in FIG. 16 and also with reference to FIG. 18, the annular wiper seal 366 may slide along and clean (e.g., wipe) a second portion 418 of the radially-inner surface of the wellhead housing 350 prior to contact between the annular seals 362 and the second portion 418 of the radially-inner surface of the wellhead housing 350. In this way, the annular wiper seal 366 may also protect the annular seals 362 from wear, abrasion, and so forth. It should be appreciated that the seal assembly 364 may have any suitable number of annular seals 362, such as 1 , 2, 3, 4, or more stacked or spaced apart along the axial axis 44. Additionally, it should be appreciated that any suitable number of annular wiper seals 366 may be provided, such as 1 , 2, 3, 4, or more stacked or spaced apart along the axial axis 44.

[00106] Further, with reference to the inset provided in FIG. 16 and also FIG. 18, the respective grooves 414 are positioned between the annular seals 362 along the axial axis 44. Additionally, the respective grooves 414 are axially aligned with and are surrounded by the first portion 416 of the radially-inner surface of the wellhead housing 350 during the cementing operations. This placement and configuration blocks contact between the fluid flow that travels through the passage 352 and the respective grooves 414, thereby protecting the respective grooves 414 from wear, abrasion, debris buildup, and so forth. Additionally, the annular wiper seal 366 may slide along and clean (e.g., wipe) the second portion 418 of the radially-inner surface of the wellhead housing 350 prior to axial alignment and engagement between the respective grooves 414 and the one or more locks 390. In this way, the annular wiper seal 366 may also facilitate the engagement between the respective grooves 414 and the one or more locks 390 (e.g., by removing or block debris buildup). It should be appreciated the lock ring 388 may be incorporated into and/or adapted for use with any of a variety of wellheads and/or hangers, including any wellhead and/or hanger described herein.

[00107]

[00108] FIGS. 19-22 are cross-sectional side views of an embodiment of a portion of the wellhead 12, wherein a wellhead housing 600 includes one or more grooves 602. A seal assembly 204 is configured to move within the wellhead housing 600 to selectively seal the one or more grooves 602 from a passage 606 (e.g., annular space) axially above a hanger 608. As shown, the seal assembly 604 may include annular seals 605 supported in annular seal grooves 607 formed in the hanger 608 (e.g., a body of the hanger 608; a single, solid body that includes the annular seal grooves 607 for the annular seals 605 and that supports a casing 610).

[00109] In certain embodiments, the wellhead housing 600 also includes housing protrusions 612 (e.g., teeth). The housing protrusions 612 extend radially inwardly from a radially inner surface of the wellhead housing 600. The housing protrusions 612 may include one or more protrusions stacked axially relative to one another and arranged in a slotted or segmented design, as shown in an inset provided in FIG. 19. For example, the housing protrusions 612 may include three protrusions stacked axially and arranged in three segments distributed (e.g., spaced apart) circumferentially about the wellhead housing 600. The one or more grooves 602 and the housing protrusions 612 may be offset from one another along the circumferential axis 48 (e.g., alternate about the circumferential axis 48).

[00110] In certain embodiments, the hanger 608 also includes hanger protrusions 614 (e.g., teeth). The hanger protrusions 614 extend radially outwardly from a radially outer surface of the hanger 608. The hanger protrusions 614 may include one or more protrusions stacked axially relative to one another and arranged in a slotted or segmented design, as shown in an inset provided in FIG. 19. For example, the hanger protrusions 614 may include three protrusions stacked axially and arranged in three segments distributed (e.g., spaced apart) circumferentially about the hanger 608. The hanger protrusions 614 may be sized to engage and fit within the housing protrusions 612 (e.g., stack along the axial axis 44 and overlap along the radial axis 46; contact to support the hanger 608 within the wellhead housing 600) when the hanger protrusions 614 align with the housing protrusions 612 along the circumferential axis 48. Further, the hanger protrusions 614 may be sized to open or expose the one or more grooves 602 (e.g., not overlap along the radial axis 46; radially inwardly of the one or more grooves 602) when the hanger protrusions 614 align with the one or more grooves 602 along the circumferential axis 48 (e.g., and offset from the housing protrusions 612 along the circumferential axis 48).

[00111] As shown in FIGS. 19-22, the seal assembly 604 is axially aligned with the one or more grooves 602 and the hanger protrusions 614 are circumferentially aligned with the one or more grooves 602 to enable fluid flow to travel axially across the seal assembly 604 from a first axial position below the seal assembly 604 (e.g., relative to a wellbore; an annular space between the hanger 608 and the wellhead housing 600) to a second axial position above the seal assembly 604 (e.g., relative to the wellbore; to enter the passage 606). In particular, the fluid flow may travel into the one or more grooves 602, as well as around and/or through unsealed flow paths defined between the hanger 608 and the wellhead housing 600 to travel axially across the seal assembly 604 from the first axial position to the second axial position. As shown, the one or more grooves 602 provide an enlarged inner diameter of the wellhead housing 600 (e.g., relative to portions of the wellhead housing 600 above and/or below the one or more grooves 602), such that the seal assembly 604 (e.g., the annular seals 605 of the seal assembly 604) do not contact and do not form an annular seal against a radially inner surface of the wellhead housing 600 when the seal assembly 604 is axially aligned with the one or more grooves 602.

[00112] Various features of the wellhead housing 600 and the hanger 608 may facilitate efficient running, cementing, and sealing operations. For example, as shown in FIG. 19, a running tool 616 may run the hanger 608 with the seal assembly 604 into the wellhead housing 600. A sleeve 618 (e.g., annular torque sleeve) is coupled (e.g., pinned) to the running tool 616 and castellated to the hanger 608 (e.g., castellated interface; key-slot engagement) to enable rotation of the running tool 616 to cause rotation of the hanger 608 (e.g., without unthreading the hanger 608). Additionally, a retractable pin 620 (e.g., stop) may retract or move radially outwardly with downward movement of the hanger 608 within the wellhead housing 600 (e.g., due to a tapered upper surface and biasing member).

[00113] The hanger 608 may be lowered until the hanger 608 contacts or engages one or more surfaces, such as the housing protrusions 612, that blocks further movement of the hanger 608 toward the wellbore. For example, if the hanger protrusions 614 and the housing protrusions 612 are aligned along the circumferential axis 48, the hanger protrusions 614 may land on the housing protrusions 612, which may block the further movement of the hanger 608 toward the wellbore. In such cases, the running tool 616 may be rotated to rotate the hanger 608 until the hanger protrusions 614 and the housing protrusions 612 are offset along the circumferential axis 48. Then, with reference to FIG. 24, the hanger 608 may continue to be lowered until the hanger 608 contacts or lands on a shoulder 622 of the wellhead housing 600.

[00114] As shown in FIG. 20, the hanger 608 is in a landed position in which the hanger 608 is landed on the shoulder 622 of the wellhead housing 600 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 608 relative to the wellhead housing 600 toward the wellbore). In particular, in the embodiment shown in FIG. 20, the hanger 608 is landed on the wellhead housing 600 upon contact between a hanger surface 624 and the shoulder 622 of the wellhead housing 600, and the hanger surface 624 includes lower edges or portions of the hanger protrusions 614. In such cases, the hanger surface 624 is not a complete annular surface (e.g., as the hanger protrusions 614 are distributed circumferentially about the hanger 608), and thus, radial gaps 626 (e.g., unsealed flow paths) may be provided at certain circumferential locations about the hanger 608 (e.g., radially between the hanger 608 and the wellhead housing 600).

[00115] Further, with the hanger 608 in the landed position, the seal assembly 604 is axially aligned with the one or more grooves 602 formed in the wellhead housing 600, and the one or more grooves 602 are able to provide a bypass for fluid flow across the seal assembly 604. Thus, the fluid flow may travel axially through the radial gaps 626, circumferentially into the one or more grooves 602, and then axially through the one or more grooves 602. In this way, the fluid flow may travel through the unsealed flow paths and the one or more grooves 602 to travel axially across the seal assembly 604 from the first axial position to the second axial position, such as shown by arrows 628. Accordingly, in the landed position, cementing operations may be carried out to cement the casing 610 supported by the hanger 608 in the wellbore.

[00116] With reference to FIG. 21 , once the cementing operations are complete, the running tool 616 may move the hanger 608 axially (e.g., away from the wellbore; raises the hanger 208). For example, the running tool 616 may move the hanger 608 axially until a set shoulder 630 of the hanger 608 contacts the retractable pin 620. The retractable pin 620 does not retract or move radially outwardly with upward movement of the hanger 608 within the wellhead housing 600 (e.g., due to a flat lower surface and the biasing member that biases the retractable pin 620 radially inwardly to extend from the wellhead housing 600). With contact between the set shoulder 630 of the hanger 608 and the retractable pin 620, the seal assembly 604 is axially offset from the one or more grooves 602 and forms a seal (e.g., annular seal) between the hanger 608 and the wellhead housing 600. Further, with the contact between the set shoulder 630 of the hanger 608 and the retractable pin 620, the hanger protrusions 614 are axially aligned with the housing protrusions 612. Accordingly, the running tool 616 may be rotated to rotate the hanger 608 until the hanger protrusions 614 and the housing protrusions 612 are aligned along the circumferential axis 48.

[00117] In this position or configuration, which is illustrated in FIG. 22, the seal assembly 604 is axially offset (e.g., axially above, relative to the wellbore) from the one or more grooves 602 formed in the wellhead housing 600 and the one or more grooves 602 are not able to provide the bypass for fluid flow across the seal assembly 604. Accordingly, in this position or configuration, the seal assembly 604 blocks the fluid flow to thereby protect equipment positioned axially above the seal assembly 604, for example. Additionally, engagement between the hanger protrusions 614 and the housing protrusions 612 provides support for the hanger 608, as well as the casing 610 suspended from the hanger 608. In this way, the housing protrusions 612 operate as a load shoulder to block downward movement of the hanger 608 (e.g., toward the wellbore), as well as operate as a lock to block upward movement of the hanger 608 (e.g., away from the wellbore).

[00118] In certain embodiments, the retractable pin 620 may move into a slot 632 (e.g., recess) formed in the radially outer surface of the hanger 608, which may block back spinning or reverse rotation of the hanger 608 within the wellhead housing 600. Additionally, in certain embodiments, a stop surface 634 may be provided along one side of at least one of the hanger protrusions 614 to contact and block further rotation of the hanger 608 within the wellhead housing 600. In this way, the slot 632 and the stop surface 634 may facilitate reaching and maintaining alignment of the hanger protrusions 614 and the housing protrusions 612 along the circumferential axis 48 after the cementing operations.

[00119] Further, the running tool 616 may then be separated from the hanger 608 via any suitable techniques. For example, once the hanger 608 is locked within the wellhead housing 600 (e.g., via engagement between the hanger protrusions 614 and the housing protrusions 612, and with support from the slot 632 and/or the stop surface 634), further rotation of the running tool 616 may break shear pins 636 that couple the annular sleeve 618 to the running tool 616. Accordingly, the running tool 616 may then rotate relative to the annular sleeve 618 and the hanger 608 to unthread from the hanger 608.

[00120] In certain embodiments, the annular sleeve 618 is coupled to the running tool 616, such as via pins 638 (e.g., fasteners or screws) that engage an annular grooved formed in the running tool 616. Accordingly, the running tool 616 and the annular sleeve 618 may be driven axially (e.g., away from the wellbore) together to withdraw from the wellhead housing 600. In this way, the running tool 616 may lower the hanger 608 with the casing 610, as well as the seal assembly 604, into the wellhead housing 600. Further, the seal assembly 604 may remain in the wellhead housing 600 (e.g., aligned with the one or more grooves 602; not sealed against the wellhead housing 600) during the cementing operations. However, the hanger 608 with the casing 610, as well as the seal assembly 604, may move relative to the wellhead housing 600 after the cementing operations to seal the annular space between the hanger 608 and the wellhead housing 600. In this way, the hanger 608 with the seal assembly 604 may essentially operate as a movable component that selectively seals the annular space (e.g., selectively opens or seals the groove 602; the one or more grooves 602 operate as a bypass passage). Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 608 to the wellhead housing 600 after the cementing operations.

[00121] It should be appreciated that the wellhead housing 600 and the hanger 608 shown in FIGS. 19-22 may be adapted to include different structural features. For example, the seal assembly 604 may be a separate structure (e.g., not integrated into the hanger 608) and/or the one or more grooves 602 may instead be one or more passages formed in the wellhead housing 600. In any case, the hanger 608 is lowered into the wellhead housing 600 to axially align the seal assembly 604 with the one or more grooves 602 to enable the cementing operations. Then, the hanger 608 is pulled into tension to axially offset the seal assembly 604 and the one or more grooves 602, as well as to axially align the hanger protrusions 614 and the housing protrusions 612. Then, the hanger 608 is rotated (e.g., a partial turn, such as 60 degrees) to circumferentially align the hanger protrusions 614 and the housing protrusions 612, such that the hanger 608 is then supported and locked within the wellhead housing 600.

[00122] FIGS. 23-25 are cross-sectional side views of an embodiment of a portion of the wellhead 12, wherein a wellhead housing 650 includes or is coupled to an insert 652 (e.g., annular insert or ring). Additionally, a seal assembly 654 (e.g., annular seal assembly) is positioned within the wellhead housing 650 and is configured to move to selectively block fluid flow through a passage 656 (e.g., annular space) defined radially between the insert 652 and the wellhead housing 650. A hanger 658 (e.g., a casing hanger, such as the casing hanger 36 of FIG. 1 ) is positioned in the wellhead housing 650 and suspends a casing 660 that extends into a wellbore. For example, the casing 660 may pass through an additional casing and/or a conductor to extend into the wellbore.

[00123] As shown in FIG. 23, a running tool 662 may lower the hanger 658 with the casing 660, the seal assembly 654, and a lock ring 664 (e.g., annular lock ring; c-ring) into the wellhead housing 650. The running tool 662 may lower the hanger 658 until the hanger 658 reaches a landed position in which the hanger 658 is landed on the wellhead housing 650 (e.g., axially facing or radially overlapping surfaces contact one another to block further movement of the hanger 658 relative to the wellhead housing 650 toward the wellbore). For example, as shown in FIG. 23, the hanger 658 includes a hanger surface 666 that contacts a shoulder 668 of the wellhead housing 650 to block further movement of the hanger 658 relative to the wellhead housing 650 toward the wellbore. Further, as shown in FIG. 23, the hanger surface 666 includes multiple surface portions or segments distributed about the circumferential axis 48, as multiple slots 670 (e.g., axial slots) are formed in a radially outer surface of the hanger 658. Thus, the multiple surface portions of the hanger surface 666 and the multiple slots 670 alternate about the circumferential axis 48 to enable both landing on the wellhead housing 650 (e.g., via the multiple surface portions of the hanger surface 666) and fluid flow across the hanger 658 (e.g., via the multiple slots 670) while the hanger 658 is in the landed position.

[00124] With reference to FIG. 24, in the landed position, the seal assembly 654 is axially aligned with the insert 652. Accordingly, as shown by arrows 672, a bypass pathway may be formed or provided to enable fluid flow from a first axial position within an annular space between the hanger 658 and the wellhead housing 650 (e.g., axially below the hanger 658 and the seal assembly 654), through the multiple slots 670 in the hanger 658, to a second axial position within an additional annular space between the hanger 658 and a seal body 674 of the seal assembly 654, through the passage 656 defined radially between the insert 652 and the wellhead housing 650, and then to a third axial position within a further annular space between the running tool 662 and the wellhead housing 650 (e.g., axially above the hanger 658 and the seal assembly 654). Thus, in the landed position, cementing operations may commence to cement the casing 660 within the wellbore. Advantageously, the seal assembly 154 includes annular seals 676 that contact and seal against the insert 652, which may protect the annular seals 676 during the cementing operations.

[00125] As shown in FIGS 24 and 25, the running tool 662 is coupled to the hanger 658 via corresponding threads 680 (e.g., threaded interface), which may be located axially below the seal assembly 654. Once the cementing operations are complete, the running tool 662 is rotated relative to (e.g. threaded onto; in a first rotational direction) the hanger 658 (e.g., via the corresponding threads 680). Further, the running tool 662 is coupled to the seal assembly 654 via support ring 682 (e.g., bearing) that enables the running tool 662 to rotate relative to the seal assembly 654 and that also transfers axial force from the running tool 662 to the seal assembly 654. In this way, the rotation of the running tool 662 (e.g., in the first rotational direction) may drive (e.g., via the support ring 682) the seal assembly 654 axially toward the wellbore, such as until the annular seals 676 of the seal assembly 654 contact and seal against a radially-inner surface of the wellhead housing 650 axially below the passage 656 to thereby block the fluid flow through the passage 656.

[00126] As shown in FIG. 24, shear pins 684 may block axial movement of the support ring 682 relative to the seal assembly 654 as the seal assembly 654 is driven relative to the insert 652. Then, as shown in FIG. 25, once the seal assembly 654 lands on the hanger 658 (e.g., at an interface 686), further rotation of the running tool 662 may cause the shear pins 684 may break and enable the support ring 682 to move radially between the seal body 674 and the lock ring 664, to thereby drive the lock ring 664 radially outwardly to engage the insert 652 and/or other portion of the wellhead housing 650. Thus, the lock ring 664 may lock the seal assembly 654 and the hanger 658 within the wellhead housing 650 (e.g., block axial movement of the seal assembly 654 and the hanger 658 relative to the wellhead housing 650). For example, the lock ring 664 may radially overlap with the insert 652 to thereby block withdrawal of the seal assembly 654 and the hanger 658 from the wellhead housing 650. In this way, the insert 652 may effectively form a corresponding groove (or at least a portion of the corresponding groove) to receive the lock ring 664.

[00127] Once the seal assembly 654 and the hanger 658 are locked within the wellhead housing 650, the running tool 662 may be rotated (e.g., in a second rotational direction) to unthread from the hanger 658 and until the running tool 662 separates from the hanger 658. Accordingly, the running tool 662 may lower the hanger 658 with the casing 660, the seal assembly 654, and the lock ring 664 into the wellhead housing 650, and the seal assembly 654 may remain in the wellhead housing 650 during the cementing operations. However, the seal assembly 654 may move relative to the wellhead housing 650 after the cementing operations to seal the annular space between the hanger 658 and the wellhead housing 650, as well as the passage 656. In this way, the seal assembly 654 essentially operates as a movable component that selectively seals the passage 656. Further, in some embodiments, no additional seal packoff elements or steps are utilized to provide the seal the hanger 658 to the wellhead housing 650 after the cementing operations. The seal assembly 654, the running tool 662 (including the support ring 682), and the hanger 658 may have any suitable interfaces that enable the operations and techniques described herein.

[00128] FIG. 26 is a flow diagram of an embodiment of a method 700 of operating a wellhead (e.g., the wellhead 12 of FIGS. 1 -25) to efficiently route fluid through a passage of a wellhead housing and seal a hanger in the wellhead housing. The method 700 disclosed herein includes various steps represented by blocks. It should be noted that at least some steps of the method 700 may be performed as an automated procedure by a system, such as an electronic control system for the wellhead. Although the flow chart illustrates the steps in a certain sequence, it should be understood that the steps may be performed in any suitable order and certain steps may be carried out simultaneously, where appropriate.

[00129] In block 702, the method 700 may begin with running a hanger and a seal assembly into a wellhead housing. Other components, such as one or more lock rings, may also be run with the hanger and the seal assembly into the wellhead housing. The seal assembly may include one or more annular seals (e.g., elastomer or metal seals; o-rings) that are configured to seal an annular space between the hanger and the wellhead housing. The seal assembly may include the one or more annular seals supported directly on the hanger (e.g., in grooves formed in a body of the hanger; the seal assembly is integrated into the hanger or is part of hanger), or the seal assembly may include the one or more annular seals supported on an annular ring (e.g., grooves formed in the annular ring) that is coupled to and/or circumferentially surrounds a portion of the hanger.

[00130] In block 704, cementing operations may commence once the hanger and the seal assembly are positioned in the wellhead housing. During the cementing operations, the seal assembly and/or another movable seal component (e.g., a piston, a valve, a plug) may be positioned to enable a flow of fluid axially across the seal assembly via a passage formed in or along the wellhead housing. [00131] For example, the passage may include a first opening that is exposed to cement returns between the hanger and the wellhead housing below the seal assembly, as well as a second opening that is exposed to a channel or other path within the wellhead housing above the seal assembly (e.g., the channel or other path may be formed in the hanger, the running tool, and/or the annular space above the seal assembly). The passage may be open (e.g., not sealed, blocked, and/or obstructed by the seal assembly and/or the another movable seal component) to enable the flow of fluid axially across the seal assembly via the passage. As another example, the passage may include a groove (e.g., radially expanded portion; relatively large inner diameter) of the wellhead housing. The groove may be open (e.g., with a radial gap between the hanger and the groove) to enable the flow of fluid axially across the seal assembly via the groove.

[00132] In block 706, after the cementing operations, the seal assembly and/or the another movable seal component may be positioned to block the flow of fluid axially across the seal assembly via the passage formed in or along the wellhead housing. For example, the seal assembly may be moved axially relative to the passage to seal against the wellhead housing at a seal location that is axially above (e.g., relative to the wellbore) the passage (e.g., the second opening or outlet of the passage). As another example, the movable component may be a piston that is moved within the passage to fluidly disconnect the first opening from the second opening. As another example, the movable component may be a lock that is inserted to engage a valve (e.g., a check valve) within the passage to fluidly disconnect the first opening from the second opening, or a plug that is inserted into the passage to fluidly disconnect the first opening from the second opening.

[00133] While the disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. For example, while the illustrated embodiments show a hanger and a housing of a wellhead, it should be understood that the systems and methods may be adapted to for use with any of a variety of other annular structures.

[00134] Additionally, any features shown or described with reference to FIGS. 1 -26 may be combined in any suitable manner. For example, certain embodiments shown with annular seals integral to a hanger may instead include a separate seal assembly structure coupled to the hanger, and certain embodiments shown with a separate seal assembly structure coupled to the hanger may instead include annular seals integral to the hanger. As another example, certain embodiments shown with a passage through a wellhead housing may instead include a groove formed along a radially-inner surface of the wellhead housing, and certain embodiments shown with a groove formed along a radially-inner surface of a wellhead housing may instead include a passage through the wellhead housing. As yet another example, a passage formed in or along a wellhead housing may couple to a hanger passage, a tool passage, and/or any other suitable flow path (e.g., axially below and/or above a seal assembly relative to a wellbore) to facilitate techniques disclosed herein.

[00135] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function]...” or “step for [performing [a function]...”, it is intended that such elements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

Claims

1. A wellhead, comprising: a wellhead housing; a passage formed in or along the wellhead housing; a hanger configured to support a casing; and a seal assembly configured to provide an annular seal across an annular space between the hanger and the wellhead housing; wherein a movable seal component or the seal assembly is configured to move relative to the passage to selectively enable a flow of fluid across the seal assembly via the passage.

2. The wellhead of claim 1 , wherein the movable seal component or the seal assembly is configured to move relative to the hanger to selectively enable the flow of fluid across the seal assembly via the passage.

3. The wellhead of claim 1 , wherein the movable seal component of the seal assembly is configured to move axially relative to the passage to selectively enable the flow of fluid across the seal assembly via the passage.

4. The wellhead of claim 1 , wherein the movable seal component of the seal assembly is configured to move radially relative to the passage to selectively enable the flow of fluid across the seal assembly via the passage.

5. The wellhead of claim 1 , comprising an additional passage formed in or along the wellhead housing, wherein an additional movable seal component or the seal assembly is configured to move relative to the additional passage to selectively enable the flow of fluid across the seal assembly via the additional passage.

6. The wellhead of claim 1 , comprising the movable seal component, wherein the movable seal component comprises a piston, a valve, or a plug, and the movable seal component is configured to move relative to the passage to selectively enable the flow of fluid across the seal assembly via the passage.

7. The wellhead of claim 6, wherein the seal assembly is integrated into the hanger, and the movable seal component is configured to move relative to the seal assembly and the hanger to selectively enable the flow of fluid across the seal assembly via the passage.

8. The wellhead of claim 1 , wherein the seal assembly is configured to move between a first axial position and a second axial position relative to the passage and relative to the hanger to selectively enable the flow of fluid across the seal assembly via the passage.

9. The wellhead of claim 1 , wherein the seal assembly is configured to move relative to the passage to axially align the seal assembly with the passage to enable the flow of fluid across the seal assembly via the passage.

10. The wellhead of claim 9, wherein the seal assembly is configured to move relative to the passage to axially offset the seal assembly from the passage to provide the annular seal across the annular space between the hanger and the wellhead housing to block the flow of fluid across the seal assembly via the passage.

11. The wellhead of claim 9, wherein the seal assembly is positioned axially between an inlet of the passage and an outlet of the passage while the seal assembly is axially aligned with the passage.

12. The wellhead of claim 1 , wherein the passage extends through a wall of the wellhead housing.

13. The wellhead of claim 1 , wherein the flow of fluid comprises cement returns.

14. A method of operating a wellhead, the method comprising: running a hanger and a seal assembly into a wellhead housing; routing a flow of fluid across the seal assembly via a passage formed in the wellhead housing during cementing operations with the hanger and the seal assembly in the wellhead housing; and after the cementing operations, moving a movable component or the seal assembly relative to the wellhead housing to block the flow of fluid across the seal assembly and to seal an annular space between the hanger and the wellhead housing with the seal assembly.

15. The method of claim 14, wherein the seal assembly is axially aligned with the passage while the seal assembly during the cementing operations.

16. The method of claim 14, comprising, after the cementing operations, moving the seal assembly axially relative to the wellhead housing and relative to the hanger to block the flow of fluid across the seal assembly and to seal the annular space between the hanger and the wellhead housing with the seal assembly.

17. The method of claim 14, comprising, after the cementing operations, moving the movable seal component relative to the wellhead housing and relative to the hanger to block the flow of fluid across the seal assembly and to seal the annular space between the hanger and the wellhead housing with the seal assembly, wherein the movable seal component comprises a piston, a valve, or a plug.

18. The method of claim 16, wherein the flow of fluid comprises cement returns.

19. A wellhead, comprising: a wellhead housing; a passage formed in the wellhead housing; a hanger configured to support a casing; and a seal assembly configured to move relative to the hanger between a first axial position and a second axial position within the wellhead housing; wherein, in the first axial position, the seal assembly enables a flow of fluid across the seal assembly via the passage; wherein, in the second axial position, the seal assembly blocks the flow of fluid across the seal assembly via the passage and provides an annular seal across an annular space between the hanger and the wellhead housing.

20. The wellhead of claim 19, wherein, in the first axial position, the seal assembly is axially aligned with the passage.