Subsea wellhead assembly

Patent metadata

Field	Value
Publication number	US-11506012-B2
Application number	US-201716313395-A
Country	US
Kind code	B2
Filing date	Jul 5, 2017
Priority date	Jul 5, 2016
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

A method of installing or removing a subsea wellhead assembly is provided. The method comprising providing a suction anchor that in use acts as a subsea well foundation, wherein the suction anchor comprises an outer suction skirt; and an inner member, wherein the inner member comprises a high pressure wellhead housing; and installing or removing the suction anchor together with the high pressure wellhead housing on or from a seabed.

First claim

The invention claimed is:

1. A suction anchor for forming, or having previously formed, a subsea well assembly at an upper end of a subsea well and with the well extending through the suction anchor, the suction anchor comprising:
an outer suction skirt; and
an inner member integral with the outer suction skirt, wherein the inner member comprises a conductor housing and a high pressure wellhead housing but does not comprise a low pressure conductor pipe, and the conductor housing holds and supports the high pressure wellhead housing, and
wherein the outer suction skirt and the inner member are positioned relative to each other so that any casing strings or pipes hung from the high pressure wellhead housing extend through the volume surrounded by the outer suction skirt.

2. The suction anchor according to claim 1 , wherein the inner member does not comprise a central suction anchor tube.

3. The suction anchor according to claim 1 , wherein the inner member of the suction anchor comprises a wellhead housing extension pipe.

4. The suction anchor according to claim 1 , wherein the conductor housing is received within a conductor housing receptacle and is mechanically fixed to the suction anchor within the conductor housing receptacle.

5. A subsea wellhead installation and/or removal apparatus, the wellhead installation apparatus comprising a suction anchor according to claim 1 and a device connected to the high pressure wellhead housing for permitting the suction anchor to be lowered and/or lifted subsea, wherein the device is a well control device, a subsea tree or a capping stack.

6. The subsea wellhead installation and/or removal apparatus according to claim 5 , wherein the device further comprises at least one of a device for adjusting the pressure inside the suction anchor, or a verticality measuring and controlling device.

7. A method of installing or uninstalling a subsea wellhead assembly, the method comprising:
providing a suction anchor according to claim 1 that in use acts as a subsea well foundation located at an upper end of a subsea well and with the well extending through the suction anchor; and
installing or uninstalling the suction anchor together with the high pressure wellhead housing on or from a seabed.

8. The method according to claim 7 , wherein the method comprises connecting a device to the high pressure wellhead housing such that the suction anchor is held by the device connected to the high pressure wellhead housing during installation or uninstallation, and wherein the device is a well control device, a subsea tree or a capping stack.

9. The method according to claim 8 , wherein the device connected to the high pressure wellhead housing is further comprises at least one of a device for adjusting the pressure inside the suction anchor, or a device for measuring and controlling the verticality of the device connected to the high pressure wellhead housing.

10. The suction anchor according to claim 1 , wherein the suction anchor further comprises a top structure, wherein the top structure comprises a plurality of radiating fins that are fixed to the top of the suction anchor, and the fins are in the form of I-beams.

11. A subsea wellhead assembly located at an upper end of a subsea well, the subsea well head assembly comprising:
a conductor housing;
a suction anchor comprising an outer suction skirt and an inner pipe connected to the outer suction skirt,
wherein the conductor housing does not support a conductor pipe,
wherein the assembly does not comprise a conductor pipe,
wherein the conductor housing is supported by the suction anchor such that loads can be transferred from the conductor housing to the suction anchor, and
wherein the conductor housing is located above the inner pipe.

12. The subsea wellhead assembly according to claim 11 , wherein the assembly comprises a high pressure wellhead housing and wherein the high pressure wellhead housing is located within and supported by the conductor housing, and wherein the high pressure wellhead housing is attached to and supports a wellhead extension pipe.

13. The subsea wellhead assembly according to claim 11 , wherein the conductor housing is connected near or at its top end and near or at its bottom end to the suction anchor.

14. The subsea wellhead assembly according to claim 11 , wherein the conductor housing is received in a conductor housing receptacle and mechanically fixed to the suction anchor.

15. The subsea wellhead assembly according to claim 11 , wherein a bottom of the conductor housing is received on and supported by a mount attached to the suction anchor, and wherein the conductor housing is locked in position relative to the suction anchor via a clamp, and wherein the clamp and mount each provide a path for loads to be transmitted from the conductor housing to the suction anchor.

16. The subsea wellhead assembly according to claim 11 , wherein a high pressure wellhead housing is landed in the conductor housing, and wherein the high pressure wellhead housing does not support a wellhead housing extension pipe.

17. A subsea wellhead assembly located at an upper end of a subsea well comprising:
a high pressure wellhead housing; and
a suction anchor comprising an outer suction skirt and an inner pipe connected to the outer suction skirt, wherein the high pressure wellhead housing does not support a wellhead housing extension pipe,
wherein a casing hanger that supports a casing is landed in the high pressure wellhead housing, and wherein the inner pipe of the suction anchor is immediately around the casing.

18. The subsea wellhead assembly according to claim 17 , wherein the high pressure wellhead housing is located within and supported by a conductor housing, and wherein the conductor housing does not support a conductor pipe.

Assignees

• Equinor Energy As

Inventors

• Reinås Lorents
• Wernø Tore Geir
• Saether Morten
• Nesse Harald Sigurd

Classifications

• E21B33/038 Primary

  Connectors used on well heads, e.g. for connecting blow-out preventer and riser · CPC title

• E21B41/08

  Underwater guide bases, e.g. drilling templates; Levelling thereof · CPC title

• E02D27/18

  Foundations formed by making use of caissons · CPC title

• E21B33/035 Primary

  specially adapted for underwater installations (E21B33/043, E21B33/064, E21B33/076 take precedence) · CPC title

• E02D27/52

  Submerged foundations {, i.e. submerged in open water (E02D27/12 - E02D27/24 take precedence)} · CPC title