Riser isolation tool for deepwater wells

Patent metadata

Field	Value
Publication number	US-9605490-B2
Application number	US-201414773670-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Sep 3, 2014
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

In a subsea drilling operation, a riser isolation tool may be installed inside a marine riser between the subsea wellhead and the rig floor to provide a conduit having a higher pressure rating than the original riser itself. In some embodiments, the riser isolation tool includes a tubular body and, extending therefrom, a seal stinger sized to be slidably received in a receptacle seated in the wellhead. Additional apparatus, systems, and methods are disclosed.

First claim

What is claimed is:

1. A method, comprising:
installing a marine riser to provide an initial conduit between a subsea blowout preventer mounted above a subsea wellhead and a surface drilling facility, the marine riser comprising an upper part and a lower part slidably coupled therewith;
removing the upper part of the marine riser;
after removal of the upper part of the marine riser, running a riser isolation tool through the lower part of the marine riser, the riser isolation tool comprising a body section having burst and collapse pressure ratings exceeding burst and collapse pressure ratings of the marine riser and, connected to the body section at a lower end thereof, a seal stinger;
inserting the seal stinger into a receptacle seated in the wellhead to mount the seal stinger slidably in the receptacle, and sealing the seal stinger against an interior wall of the receptacle; and
installing an upper blowout preventer between an upper end of the riser isolation tool and the surface drilling facility.

2. The method of claim 1 , wherein installing the upper blowout preventer comprises securing the upper blowout preventer to the surface drilling facility via a bell nipple.

3. The method of claim 1 , wherein the upper part of the marine riser is removed, the riser isolation tool is run through the lower part of the marine riser, the seal stinger is inserted into the receptacle, and the upper blowout preventer is installed prior to penetrating a reservoir during drilling.

4. A system comprising:
a lower marine riser part extending upward from a subsea blowout preventer mounted on a wellhead;
a receptacle hung from the wellhead; and
a riser isolation tool installed inside the lower marine riser part and having a maximum outer diameter smaller than an inner diameter of the lower marine riser part with an upper end of the riser isolation tool extending upward from an upper end of the lower marine riser part, the riser isolation tool comprising:
a tubular tool body having burst and collapse pressure ratings exceeding the burst and collapse pressure ratings of the lower marine riser part; and
a seal stinger comprising (i) a tubular component connected to a lower end of the tool body and sized to fit inside the receptacle, and (ii) disposed at multiple locations along a length of the tubular component, seal stacks circumferentially surrounding the tubular component.

5. The riser isolation tool of claim 4 , wherein the tool body comprises 2014 aluminum alloy.

6. The riser isolation tool of claim 4 , wherein the tool body has a burst rating exceeding the burst rating of an L-80 grade steel marine riser by a factor of at least two.

7. The riser isolation tool of claim 4 , wherein the tool body and the tubular component of the seal stinger form a continuous tubular structure of uniform inner diameter.

8. The riser isolation tool of claim 4 , wherein the tool body has an outer diameter of about 19 inches and an inner diameter of about 12.5 inches.

9. The riser isolation tool of claim 4 , wherein an outer diameter of the tubular component of the seal stinger is smaller than an outer diameter of the tool body.

10. The riser isolation tool of claim 4 , wherein the seal stacks comprise sealing rings seated in circumferential grooves of the tubular component of the seal stinger.

11. The riser isolation tool of claim 4 , wherein the seal stinger has a length of between about twenty feet and about sixty feet.

12. A riser isolation system comprising:
a riser isolation tool for installation at least partially inside a marine riser between a wellhead and a surface drilling facility, the riser isolation tool comprising a body section having burst and collapse pressure ratings exceeding burst and collapse pressure ratings of the marine riser and, connected to the body section at a lower end thereof, a seal stinger having a smaller outer diameter than the body section and being configured to be slidably received in and sealed against a receptacle seated in the wellhead; and
an upper blowout preventer for insertion between an upper end of the body section and the surface drilling facility, wherein installation of the upper blowout preventer secures the body section to the surface facility.

13. The system of claim 12 , wherein the upper blowout preventer is rated for at least 15,000 psi.

14. The system of claim 12 , wherein the receptacle comprises a polished bore receptacle.

15. The system of claim 12 , wherein the riser isolation tool comprises 2014 aluminum alloy.

16. The system of claim 12 , wherein the riser isolation tool has a burst rating exceeding the burst rating of an L-80 marine riser by a factor of at least two.

17. The system of claim 12 , wherein the riser isolation tool has an outer diameter smaller than an inner diameter of the marine riser.

18. The system of claim 12 , wherein the seal stinger comprises a tubular component connected to the lower end of the body section and, disposed at multiple locations along a length of the tubular component, seal stacks circumferentially surrounding the tubular component.

19. The system of claim 18 , wherein the seal stacks comprise sealing rings seated in circumferential grooves of the tubular component of the seal stinger.

20. The system of claim 12 , wherein the seal stinger has a length of between about twenty feet and about sixty feet.

Assignees

• Halliburton Energy Services Inc

Inventors

• Hess Joe E
• Cuthbert Andrew John
• Courville Ronald Wayne

Classifications

• E21B33/038

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

• E21B33/064

  specially adapted for underwater well heads · CPC title

• E21B17/1007

  for the internal surface of a pipe, e.g. wear bushings for underwater well-heads · CPC title

• E21B17/01 Primary

  Risers · CPC title