Apparatus and method for testing a blowout preventer

1. An apparatus comprising:

a drill bit mounted in a drill string;

a drilling tool mounted in the drill string, the drilling tool being configured to be located and used in a wellhead below a blowout preventer (BOP), the drilling tool having fluid ports therein; and

a collar configured to be located between the drilling tool and the BOP, 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 below a chamber in the BOP.

2. An apparatus according to claim 1 , wherein a surface of the collar is complementary 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 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.

5. An apparatus according to claim 1 , wherein the apparatus further comprises a wear bushing for locating in the well head, and, wherein the drilling tool is sealable against the wear bushing.

6. 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.

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

8. 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 below a BOP, the drilling tool having fluid ports therein;

running a collar into the wellhead, the collar mating with the drilling tool below the BOP;

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;

wherein the drilling tool is part of a drill string, the drill string comprising a drill bit.

9. A method according to claim 8 , wherein the fluid is pumped into the chamber to build up the fluid pressure in the chamber.

10. A method according to claim 8 , wherein for the blowout preventer (BOP) test, the fluid pressure in the chamber may be from 5,000 psi to 10,000 psi.

11. A method according to claim 8 , 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.

12. A method according to claim 8 , wherein the method further includes the step of releasably attaching a mandrel to the drilling tool using one or more dogs on the mandrel.

13. A method according to claim 8 , wherein the method further includes the step of locating a wear bushing in the wellhead, the drilling tool releasably coupleable to the wear bushing.

14. A method according to claim 8 , the drill string comprising one or more of drill pipe, drill string tool(s), and drill collar(s).

15. A method according to claim 14 , 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.

16. A method according to claim 8 , the method comprising drilling with the drill string, with the drilling tool mounted in the drill string.

17. An apparatus comprising:

a drilling tool configured to be located and used in a drill string with a drill bit in a wellhead below a blowout preventer (BOP), the drilling tool having fluid ports therein; and

a collar configured to be located between the drilling tool and the BOP, the collar being mateable with the drilling tool; and

a wear bushing for locating in the wellhead,

wherein the fluid ports in the drilling tool are blocked by the collar when the collar is mated with the drilling tool below a chamber in the BOP.

18. The apparatus according to claim 17 , wherein the wear bushing is configured to be attached to a mandrel with the drilling tool for at least one of run in; and retrieval.

19. The apparatus according to claim 17 , wherein the drilling tool is configured to be located and used in the wellhead below the blowout preventer (BOP) by being attached to a mandrel while being run into the wellhead and being released from the mandrel during drilling operations downhole.