Protected annulus flow arrangement for subsea completion system

Patent metadata

Field	Value
Publication number	US-9945202-B1
Application number	US-201715470099-A
Country	US
Kind code	B1
Filing date	Mar 27, 2017
Priority date	Mar 27, 2017
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A technique facilitates protection of potentially susceptible components from unwanted exposure to well fluids or other fluids in a monobore subsea installation. The subsea installation may comprise various components, e.g. a tubing hanger and a subsea tree which form a plenum region therebetween. An annulus stab (or stabs) is positioned to extend between the tubing hanger and the subsea tree so as to provide an isolated flow path within the annulus stab and through the plenum region. The isolated flow path also may extend longitudinally through the tubing hanger until exiting through a side of the tubing hanger. The annulus stab and overall isolated flow path are thus able to accommodate an annulus flow within the monobore subsea installation while protecting components exposed to the plenum region from contact with deleterious fluids in the annulus flow path.

First claim

What is claimed is:

1. A system for use in a subsea well application, comprising:
a monobore subsea installation having:
a tubing head spool disposed above a wellhead;
a tubing hanger engaged with the tubing head spool;
a subsea tree coupled to the tubing head spool over the tubing hanger and forming a plenum region between the tubing hanger and the subsea tree;
a production stab extending between the tubing hanger and the subsea tree, the production stab being sealed with respect to both the tubing hanger and the subsea tree;
an annulus stab extending between the tubing hanger and the subsea tree to provide an isolated path within the stab and through the plenum region, the isolated path further being routed through the subsea tree, through the annulus stab, and through the tubing hanger until exiting out through a side of the tubing hanger to the tubing head spool to accommodate an annulus flow path along the monobore subsea installation; and
a plurality of valves disposed along the isolated path, the plurality of valves comprising at least one valve in the subsea tree along the isolated path and at least one valve in the tubing head spool along the isolated path.

2. The system as recited in claim 1 , wherein the annulus stab comprises at least one tubing extending between a tubing hanger annulus flow passage in the tubing hanger and a subsea tree annulus flow passage in the subsea tree.

3. The system as recited in claim 2 , wherein the subsea tree annulus flow passage is routed through the subsea tree from a bottom of the subsea tree to a top of the subsea tree.

4. The system as recited in claim 2 , wherein the tubing hanger annulus flow passage is routed longitudinally through a wall of the tubing hanger until turning radially outward to the side of the tubing hanger and into a sealed region located in communication with a corresponding annulus flow passage in the tubing head spool.

5. The system as recited in claim 4 , wherein the corresponding annulus flow passage is placed in communication with an annulus between a well tubing and a casing extending down below the tubing hanger to form an overall annulus flow passage through the monobore subsea installation.

6. The system as recited in claim 5 , further comprising a plurality of valves disposed along the overall annulus flow passage.

7. The system as recited in claim 6 , wherein at least two valves of the plurality of valves are disposed along the corresponding annulus flow passage through the tubing head spool.

8. The system as recited in claim 1 , wherein the annulus stab comprises a plurality of annulus stabs for conducting flow along the isolated path.

9. A system, comprising:
a subsea installation comprising a tubing hanger and a subsea tree mounted above the tubing hanger and forming a plenum region between the tubing hanger and the subsea tree, the subsea installation comprising a central monobore production passage and an installation annulus passage, the central monobore production passage being defined in part by a production stab extending from the subsea tree to the tubing hanger, the production stab being sealed with respect to both the subsea tree and the tubing hanger, the installation annulus passage being defined in part by an annulus stab extending from the subsea tree to the tubing hanger to isolate annulus flow of well fluid to an interior of the annulus stab, the installation annulus passage being further defined by a tubing hanger annulus flow passage routed through the tubing hanger until exiting out through a side of the tubing hanger to thus protect the plenum region from exposure to the well fluid, the subsea installation further comprising a control line extending through the plenum region and comprising control line sections joined by a pair of mating control line connectors.

10. The system as recited in claim 9 , wherein the annulus stab comprises a tube coupled between the subsea tree and the tubing hanger.

11. The system as recited in claim 10 , wherein the annulus stab comprises a plurality of annulus stabs.

12. The system as recited in claim 9 , wherein the production stab is disposed along a longitudinal center of the subsea installation.

13. The system as recited in claim 9 , wherein the annulus stab comprises a tube which extends between the tubing hanger annulus flow passage in the tubing hanger and a subsea tree annulus flow passage within the subsea tree.

14. The system as recited in claim 13 , wherein the tubing hanger annulus flow passage is routed longitudinally through a wall of the tubing hanger until turning radially outward to the side of the tubing hanger and into a sealed region located in communication with a corresponding annulus flow passage in a tubing head spool.

15. The system as recited in claim 14 , wherein the corresponding annulus flow passage is placed in communication with an annulus between a production tubing and a casing extending down below the tubing hanger to enable an annulus flow through the subsea installation.

16. A method, comprising:
providing a subsea installation with a tubing head spool, a tubing hanger coupled to the tubing head spool, and an interfacing component positioned over the tubing hanger;
positioning the subsea installation over a subsea wellhead at a subsea location;
using a central monobore through the subsea installation for production flow;
enabling an annulus flow along an annulus passage extending through a plenum region between the tubing hanger and the interfacing component;
isolating components in the plenum region from the annulus flow by containing the annulus flow within an annulus stab extending through the plenum region to form a gallery area, of the plenum region, which is no longer part of the annulus flow, the annulus flow further being within a tubing hanger annulus flow passage routed through the tubing hanger until exiting out through a side of the tubing hanger to a tubing head spool; and
if seawater is present within the gallery area of the plenum region, displacing the seawater with a different fluid.

17. The method as recited in claim 16 , wherein providing comprises providing the interfacing component in the form of a tubing hanger running tool or a subsea tree.

18. The method as recited in claim 16 , further comprising using a production stab between the tubing hanger and the interfacing component.

Assignees

• Onesubsea Ip Uk Ltd

Inventors

• June David
• Santilli Claudio

Classifications

• E21B33/035 Primary

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

• E21B33/043

  specially adapted for underwater well heads ({E21B33/0407,} E21B33/047 take precedence) · CPC title

• E21B33/04

  Casing heads; Suspending casings or tubings in well heads · CPC title

• E21B33/076

  specially adapted for underwater installations · CPC title

• E21B33/0407

  with a suspended electrical cable · CPC title