APPARATUS AND METHOD FOR TESTING A BLOWOUT PREVENTER

Abstract

An apparatus 10 comprising a drilling tool 12 for locating in a wellhead 14. The drilling tool has fluid ports 16 therein. The apparatus further comprises a collar 18 which is mateable with the drilling tool, such that the fluid ports in the drilling tool are blocked by the collar when the collar is mated with the drilling tool. In embodiments, the drilling tool is a bit runnable drill string tool. In embodiments, the apparatus further comprises a bit runnable wear bushing 22. The apparatus can advantageously be used to perform a method of testing a blowout preventer (BOP) on the subsea wellhead.

Claims

1. An apparatus comprising: a drilling tool for locating in a wellhead, the drilling tool having fluid ports therein; and a collar, the collar being mateable with the drilling tool; wherein the fluid ports in the drilling tool are blocked by the collar when the collar is mated with the drilling tool.

2. An apparatus according to claim 1, wherein a surface of the collar is complimentary with a surface of the drilling tool so that the fluid ports in the drilling tool are readily blocked by the collar when the drilling tool and collar are mated together.

3. An apparatus according to claim 1, wherein the wellhead is located subsea.

4. An apparatus according to claim 1, wherein the apparatus further comprises a wear bushing for locating in the wellhead.

5. An apparatus according to claim 1, wherein the drilling tool is one or more of a drill string tool, a drill string adapter, a bit runnable tool and a bit runnable drill string tool.

6. An apparatus according to claim 4, wherein the drilling tool is sealable against the wear bushing.

7. An apparatus according to claim 1, wherein the fluid ports are used to provide fluid communication between a first end and an opposite second end of the drilling tool when the drilling tool is in the wellhead.

8. An apparatus according to claim 1, wherein the apparatus further comprises a mandrel releasably attachable to the drilling tool.

9. A method of testing a blowout preventer (BOP) on a subsea wellhead, the method including the steps of: locating a drilling tool in a wellhead, the drilling tool having fluid ports therein; running a collar into the wellhead, the collar mating with the drilling tool; blocking the fluid ports in the drilling tool using the collar; and pumping a fluid into a chamber between the blowout preventer (BOP) on the wellhead and the collar.

10. A method according to claim 9, wherein the fluid is pumped into the chamber to build up the fluid pressure in the chamber.

11. A method according to claim 9, wherein for the blowout preventer (BOP) test, the fluid pressure in the chamber may be from 5,000 psi to 10,000 psi.

12. A method according to claim 9, wherein the blowout preventer (BOP) is considered to have passed the test if the fluid remains in the chamber at a fluid pressure of from 5,000 psi to 10,000 psi.

13. A method according to claim 9, wherein the method further includes the step of releasably attaching a mandrel to the drilling tool using one or more dogs on the mandrel.

14. A method according to claim 9, wherein the method further includes the step of locating a wear bushing in the wellhead, the drilling tool releasably coupleable to the wear bushing.

15. A method according to claim 9, wherein the drilling tool is part of a drill string, the drill string comprising one or more of drill pipe, drill string tool(s), drill collar(s) and a drill bit.

16. A method according to claim 15, wherein the method includes the step of pulling the drill string back a set distance to allow the collar to be made up with the drill string and then run back into the wellhead

Description

[0040] An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

[0041] FIG. 1 is cross-sectional view of an apparatus according to an embodiment of the present invention;

[0042] FIG. 2 is a perspective view of a drilling tool according to an embodiment of the present invention;

[0043] FIG. 3 is a perspective view of a collar according to an embodiment of the present invention; and

[0044] FIG. 4 is cross-sectional view of the collar shown in FIG. 3.

[0045] FIG. 1 shows a cross-sectional view of an apparatus 10 according to an embodiment of the present invention. The apparatus 10 comprises a drilling tool 12 for locating in a wellhead 14, the drilling tool having fluid ports therein (16, as shown in FIG. 2). The apparatus also comprises a collar 18, the collar being mateable with the drilling tool 12. The fluid ports (16, as shown in FIG. 2) in the drilling tool 12 are blocked by the collar 18 when the collar is mated with the drilling tool. The collar 18 is shown mated to the drilling tool 12 in FIG. 1.

[0046] A surface of the collar is complimentary with a surface of the drilling tool as shown at 20a & 20b . The surfaces are complimentary so that the fluid ports (16, as shown in FIG. 2) in the drilling tool 12 are blocked by the collar 18 when the drilling tool and collar are mated together, as shown in FIG. 1.

[0047] The apparatus 10 further comprises a wear bushing 22. The wear bushing 22 and drilling tool 12 are shown secured in the wellhead 14. The drilling tool 12 is a bit runnable drill string tool. The wear bushing 22 is a bit runnable wear bushing.

[0048] The drilling tool 12 is sealed against the wear bushing 22 using an O-ring 24 and PolyPak(™) seal 26 on an outer surface of the drilling tool.

[0049] The apparatus 10 further comprises a mandrel 28. The mandrel is releasably attachable to the drilling tool 12. The mandrel 28 has one or more shear pins 30a & 30b (shown broken here) for attaching the mandrel to the drilling tool 12. There are one or more spring loaded dogs 32 for attaching the drilling tool 12 to the wear bushing 22.

[0050] The method of testing a blowout preventer (BOP) on a subsea wellhead 14 includes locating the drilling tool 12 in the wellhead, the drilling tool having fluid ports therein (16, as shown in FIG. 2). The collar 18 is run into the wellhead 14, the collar mating with the drilling tool 12. The collar 18 blocks the fluid ports (16, as shown in FIG. 2) in the drilling tool 12. Fluid (not shown) can then be pumped into a chamber, partly shown at 34, between the blowout preventer (BOP) (not shown) on the wellhead 14 and the collar 18.

[0051] In use the collar 18 is held onto the drilling tool 12, the collar 18 thereby being mated with the drilling tool 12, by fluid pressure. The fluid pressure or pressure of the fluid is that provided by the fluid pumped into the chamber, partly shown at 34, between the blowout preventer (BOP) (not shown) on the wellhead 14 and the collar 18.

[0052] When testing the blowout preventer (BOP) a plug (not shown) is put in the bore of the mandrel 28 to block this fluid path.

[0053] FIG. 2 shows a perspective view of the drilling tool 12 according to an embodiment of the present invention. The fluid ports 16 are shown. The drilling tool 12 also has one or more shear pins 36, that like spring loaded dogs 32, are used for running the wear bushing.

[0054] The mandrel 28 is part of the drill string (not shown). The drilling tool 12 also has an anti-rotation key 38 and shear pin 40.

[0055] FIG. 3 shows a perspective view of a collar 18 according to an embodiment of the present invention. The collar 18 is shown made up with the mandrel 28 as part of the drill string.

[0056] FIG. 4 shows a cross-sectional view of the collar 18 and mandrel 28 shown in FIG. 3. FIG. 4 also shows seals 42 on an inner surface of the collar 18. These are used to improve the seal between the collar 18 and drilling tool (12, as shown in FIGS. 1 & 2).

[0057] Modifications and improvements can be incorporated herein without departing from the scope of the invention.