US-12624609-B2 - Wellhead system and method of operating a wellhead system

Abstract

A wellhead system includes a wellhead assembly and a landing assembly. The wellhead assembly is secured to a top of a borehole and has an interior surface enclosing a main passage. The landing assembly incudes a tubing hanger and an orientation control assembly. The landing assembly is lowered into the main passage to land the tubing hanger in the wellhead assembly. The orientation control assembly includes an orientation engagement assembly, an actuator system which moves the orientation engagement assembly between a retracted configuration and an engaged configuration where orientation engagement assembly engages with the interior surface of the wellhead assembly, a motor, and a drive part which engages with the orientation engagement assembly and, when the orientation engagement assembly is in the engaged configuration, to be driven by the motor and to rotate the tubing hanger relative to the wellhead assembly about a longitudinal axis of the landing assembly.

Inventors

• Stuart Spitz
• Adne Oestebroet
• Sigve Angell Arnoey

Assignees

• ONESUBSEA AS

Dates

Publication Date

20260512

Application Date

20240617

Priority Date

20230615

Claims (20)

1. 1 . A wellhead system comprising: a wellhead assembly which is generally tubular and which is configured to be secured to a top of a borehole, the wellhead assembly comprising a main passage having a longitudinal axis, and an interior surface which encloses the main passage; and a landing assembly comprising a tubing hanger, a longitudinal axis, and an orientation control assembly; wherein the landing assembly is configured to be lowered into the main passage of the wellhead assembly to land the tubing hanger in the wellhead assembly; wherein the orientation control assembly comprises: an orientation engagement assembly comprising a segmented sleeve having a plurality of locking segments arranged circumferentially around the longitudinal axis; an actuator system which is configured to move the orientation engagement assembly between a retracted configuration and an engaged configuration in which the segmented sleeve engages with the interior surface of the wellhead assembly, wherein the segmented sleeve is driven from the retracted configuration to the engaged configuration via an angled interface between the segmented sleeve and an energizing member, wherein the energizing member is configured to move in a first direction to energize the segmented sleeve along the angled interface and cause at least the plurality of locking segments of the segmented sleeve to expand in a second direction crosswise to the first direction; a motor; and a drive part which is configured to engage with the orientation engagement assembly and, when the orientation engagement assembly is in the engaged configuration, to be driven by the motor and to rotate the tubing hanger relative to the wellhead assembly about the longitudinal axis of the landing assembly.
2. 2 . The wellhead system as recited in claim 1 , wherein, when the orientation engagement assembly is in the engaged configuration and is also engaged with the drive part, the orientation engagement assembly and drive part are configured to prevent a rotation of the landing assembly relative to the wellhead assembly in the absence of an operation of the motor.
3. 3 . The wellhead system as recited in claim 1 , wherein the drive part is connected to the motor so that an operation of the motor rotates the drive part, the drive part comprises a pinion gear having a plurality of radially outwardly pointing teeth, the orientation engagement assembly comprises an orientation engagement part comprising an annular gear having a plurality of radially inwardly pointing teeth configured to mesh with the plurality of radially outwardly pointing teeth of the drive part, the pinion gear is disposed inside of the annular gear, the pinion gear has a first rotational axis radially offset from both the longitudinal axis and a second rotational axis of the annular gear, and the second rotational axis of the annular gear is coaxial with the longitudinal axis.
4. 4 . The wellhead system as recited in claim 1 , wherein the first direction is an axial direction along the longitudinal axis, and the second direction is a radial direction relative to the longitudinal axis.
5. 5 . The wellhead system as recited in claim 4 , wherein the segmented sleeve comprises a collet having the plurality of locking segments, the energizing member comprises an energizer sleeve extending at least partially around a circumference of the collet, and the angled interface comprises a first tapered surface of the energizer sleeve configured to engage with a second tapered surface of the collet.
6. 6 . The wellhead system as recited in claim 1 , wherein the first direction is a rotational direction around the longitudinal axis, and the second direction is a radial direction relative to the longitudinal axis.
7. 7 . The wellhead system as recited in claim 6 , wherein the segmented sleeve comprises an annular dog cage having the plurality of locking segments disposed in a respective plurality of windows in the annular dog cage, the energizing member comprises an orientation engagement part extending circumferentially around the longitudinal axis inside of the annular dog cage, and the angled interface comprises a plurality of camming surfaces of the orientation engagement part configured to engage with a respective plurality of radially inward facing surfaces of the plurality of locking segments.
8. 8 . The wellhead system as recited in claim 1 , wherein the actuator system is further configured to be driven by the motor and by the drive part to move the plurality of locking segments, and thereby the segmented sleeve, from the retracted configuration to the engaged configuration; wherein the drive part rotates the landing assembly about the longitudinal axis of the landing assembly once the plurality of locking segments, and thereby the segmented sleeve, is in the engaged configuration.
9. 9 . The wellhead system as recited in claim 1 , wherein the actuator system is configured to be moved via a supply of a pressurized fluid to the actuator system to move the plurality of locking segments, and thereby the segmented sleeve, from the retracted configuration to the engaged configuration.
10. 10 . The wellhead system as recited in claim 1 , wherein the orientation control assembly further comprises an orientation sensor assembly which is configured to measure an orientation of the tubing hanger; wherein a controller is connected to the motor and to the orientation sensor assembly, the controller being configured to control an operation of the motor and to receive a signal from the orientation sensor assembly which is indicative of the orientation of the tubing hanger.
11. 11 . The wellhead system as recited in claim 1 , further comprising: a soft landing device which is operable to allow a downward movement of the tubing hanger in the wellhead assembly through a travel distance after an initial engagement of the tubing hanger with a landing surface provided on the wellhead assembly from an initial landing position to a final landing position.
12. 12 . The wellhead system as recited in claim 11 , wherein the orientation engagement assembly and the drive part are configured to remain engaged as the tubing hanger moves from the initial landing position to the final landing position.
13. 13 . The wellhead system as recited in claim 1 , wherein the drive part comprises a first gear having a plurality of radially outwardly pointing teeth each of which comprise a radially outwardly pointing ridge which extends generally parallel to the longitudinal axis of the landing assembly; wherein the orientation engagement assembly comprises an orientation engagement part which comprises a second gear having a plurality of radially inwardly pointing teeth which are configured to mesh with the plurality of radially outwardly pointing teeth of the drive part, wherein a first number of the plurality of radially outwardly pointing teeth of the first gear is less than a second number of the plurality of radially outwardly pointing teeth of the second gear.
14. 14 . The wellhead system as recited in claim 13 , further comprising: a soft landing device which is operable to allow a downward movement of the tubing hanger in the wellhead assembly through a travel distance after an initial engagement of the tubing hanger with a landing surface provided on the wellhead assembly from an initial landing position to a final landing position; wherein the radially outwardly pointing ridge of each of the plurality of radially outwardly pointing teeth of the drive part which extend generally parallel to the longitudinal axis of the landing assembly further extend along a distance which is at least as long as the travel distance of the tubing hanger so that the orientation engagement assembly and drive part can remain engaged as the tubing hanger moves from the initial landing position to the final landing position.
15. 15 . The wellhead system as recited in claim 1 , comprising: a plurality of idler gears; wherein the drive part comprises a pinion gear, the pinion gear and the plurality of idler gears each have a plurality of radially outwardly pointing teeth, and the pinion gear and the plurality of idler gears are circumferentially spaced apart from one another about the longitudinal axis; wherein the orientation engagement assembly comprises an orientation engagement part comprising an annular gear having a plurality of radially inwardly pointing teeth which are configured to mesh with the plurality of radially outwardly pointing teeth of the pinion gear and the plurality of idler gears, the teeth of the orientation engagement assembly each comprising a radially inwardly pointing ridge which extends generally parallel to the longitudinal axis of the main passage of the wellhead assembly.
16. 16 . The wellhead system as recited in claim 15 , further comprising: a soft landing device which is operable to allow a downward movement of the tubing hanger in the wellhead assembly through a travel distance after an initial engagement of the tubing hanger with a landing surface provided on the wellhead assembly from an initial landing position to a final landing position; wherein the radially inwardly pointing ridge of each of the plurality of radially inwardly pointing teeth of the orientation engagement part which extend generally parallel to the longitudinal axis of the main passage of the wellhead assembly further extend along a distance which is at least as long as the travel distance of the tubing hanger so that the orientation engagement assembly and drive part can remain engaged as the tubing hanger moves from the initial landing position to the final landing position.
17. 17 . A method of operating the wellhead system as recited in claim 1 , the method comprising the acts of: a) mounting the landing assembly on an end of a landing string; b) lowering the landing assembly into the wellhead assembly; c) operating the actuator system to move the orientation engagement assembly into the engaged configuration with the interior surface of the wellhead assembly; and d) operating the motor to rotate the tubing hanger to a desired orientation relative to the wellhead assembly.
18. 18 . The method as recited in claim 17 , wherein act b) further comprises lowering the landing assembly into the wellhead assembly to land the tubing hanger on a landing surface provided on the interior surface of the wellhead assembly.
19. 19 . The method as recited in claim 17 , wherein the wellhead system further comprises a soft landing device which is operable to allow a downward movement of the tubing hanger in the wellhead assembly through a travel distance after an initial engagement of the tubing hanger with a landing surface provided on the wellhead from an initial landing position to a final landing position; wherein act b) further comprises lowering the landing assembly into the wellhead assembly to land the tubing hanger in the initial landing position on the landing surface provided on the interior surface of the wellhead assembly; wherein the method further comprises, after performing act d): lowering the landing assembly further into the wellhead so that the tubing hanger moves from the initial landing position to the final landing position.
20. 20 . The method as recited in claim 19 , wherein the orientation engagement assembly is retained in the engaged configuration while the tubing hanger is lowered from the initial landing position to the final landing position.

Description

CROSS REFERENCE TO PRIOR APPLICATIONS Priority is claimed to Great Britain Patent Application GB 2308950.1, filed Jun. 15, 2023. The entire disclosure of said application is incorporated by reference herein. FIELD The present invention relates to a wellhead system, in particular, but not exclusively to, a wellhead system including an orientation system for verifying the orientation of a tubing hanger relative to a wellhead, and a method of operating a wellhead system. BACKGROUND A wellhead system typically comprises a wellhead housing mounted at the upper end of a wellbore, and a tubing hanger which is secured to the wellhead housing. The tubing hanger supports a long tubing string (known as production tubing) which extends down into the wellbore and which provides a conduit for the flow of formation fluid out of the wellbore. The tubing hanger may be supported by a tubing spool which is mounted on top of the wellhead, or directly in the wellhead housing. For a subsea wellhead, during the completion of the wellhead system, a blowout preventer (BOP) stack is mounted on the wellhead housing or, where a tubing spool is used, on the tubing spool, and a riser extends upwards from the BOP stack to a surface rig or vessel. The tubing hanger and associated production tubing is installed by securing a tubing hanger running tool to the tubing hanger, and using a landing string to lower the tubing hanger running tool etc. down the riser towards the wellhead, and land the tubing hanger in the desired position in the tubing spool/wellhead housing. The tubing hanger running tool can then be disconnected from the tubing hanger, and the landing string and tubing hanger running tool lifted out of the riser. The well is then prepared for completion by temporarily plugging the tubing hanger/production tubing, and removing the riser and BOP. A Christmas tree is them mounted on top of the tubing spool/wellhead housing, and the Christmas tree connected, via a tie-in arrangement, to production flow lines which carry the formation fluids flowing out of the wellbore. In order to provide that the tie-in connections between the Christmas tree and the production flowlines are properly made up, it is important to land the Christmas tree so that it is oriented in a predetermined orientation relative to the wellhead housing and associated external structures such as a permanent guide base or template. If the Christmas tree is rotated about the longitudinal axis of the wellhead housing by even a few degrees from the desired orientation, a proper make-up of the tie-in connectors may be impossible. Tubing hangers often provide conduits for communication between topside and the space in the wellhead below the tubing hanger, for example, for communication with or operation of sensors or equipment in the wellbore. These could be conduits for fluid flow, or comprise connections for the transmission of electrical or optical signals. Stab connectors or the like are typically provided at the upper end of the tubing hanger to provide for the connection to these conduits/connections, and these mate with corresponding connectors provided on the Christmas tree when the Christmas tree is landed on the wellhead. Because of these connections between the Christmas tree and the tubing hanger, the orientation of the Christmas tree is set by the orientation of the tubing hanger relative to the wellhead housing. It is therefore critical that when the tubing hanger is landed in the wellhead it is correctly oriented relative to the wellhead in order to provide that the orientation of the Christmas tree is correct when it is eventually landed. Any misalignment of the tubing hanger may not become apparent until after the well is completed, and the riser and BOP removed, and a dedicated measurement tool is landed on the tubing hanger, and tested. To remedy the situation at this point, it is necessary to reinstall the BOP and riser, and to pull and reinstall the tubing hanger, a process which is enormously time consuming and expensive. It will be appreciated that when the wellhead is located in deep water, the landing string can be very long, and there can be a significant twisting of the landing string as the tubing hanger running tool and tubing hanger are lowered down the riser. As such, knowledge of the orientation of the tubing hanger running tool/tubing hanger when it was first lowered into the riser does not assist in providing a sufficiently accurate knowledge of the orientation of the tubing hanger running tool once it has been lowered down the riser and is approaching the wellhead landing shoulder. Providing a mechanical orientation system in which a formation such as a pin or key, which is mounted on a part secured relative to the wellhead housing (typically in the BOP stack), interacts with an helical groove or ridge arranged around a part secured relative to the tubing hanger, in order to rotate the tubing hanger into the required orientation relative