Blowout preventer ram assembly and method of using same

1. A ram assembly for a blowout preventer for receiving a tubular of a wellbore, comprising:

a ram block disposable through the blowout preventer and positionable in sealing engagement about the tubular, the ram block having a receptacle and at least one block groove;

a ram shaft for selectively extending and retracting the ram block, the ram shaft having a ram head receivable in the receptacle, the ram head having at least one shaft groove corresponding to the at least one block groove;

a ram connector for operatively connecting the ram head to the ram block in the receptacle, the ram connector comprising at least one shear connector disposable through a surface of the ram block and the receptacle, the ram connector correspondingly receivable in the at least one block groove and the at least one shaft groove whereby the ram shaft is releasably securable to the ram block.

2. The ram assembly of claim 1 , wherein the ram connector comprises a handle.

3. The ram assembly of claim 1 , wherein the ram connector comprises a lock.

4. The ram assembly of claim 1 , wherein the at least one shaft groove is on at least one horizontal surface of the ram head.

5. The ram assembly of claim 1 , wherein the at least one shaft groove is on at least one vertical surface of the ram head.

6. The ram assembly of claim 1 , wherein the ram connector extends through a space between the ram head and the ram block.

7. The ram assembly of claim 1 , wherein the at least one block groove and the at least one shaft groove define a connection angle for receiving the ram connector.

8. The ram assembly of claim 1 , wherein the ram connector is a rod receivable in the at least one block groove and the at least one shaft groove.

9. The ram assembly of claim 1 , wherein the ram connector has one of an elliptical cross-section, a rectangular cross-section and combinations thereof.

10. The ram assembly of claim 1 , further comprising a seal disposable about the ram block for sealing engagement with the tubular.

11. The ram assembly of claim 1 , further comprising a blade disposable about the ram block for severing engagement with the tubular.

12. A method of assembling a ram assembly for receiving a blowout preventer for a tubular of a wellbore, comprising:

providing a ram assembly as in claim 1 ; and

releasably securing the ram shaft to the ram block by correspondingly disposing the at least one shear connector in the at least one block groove and the at least one shaft groove.

13. The method of claim 12 , further comprising disposing the ram head of the ram shaft in a receptacle of the ram block.

14. The method of claim 12 , wherein the step of releasably securing comprises disposing the ram connector in a space between the ram shaft and the ram block.

15. The method of claim 12 , wherein the step of releasably securing comprises disposing the ram connector through one of the ram shaft, the ram block and combinations thereof.

16. The ram assembly of claim 1 , wherein the ram block has an engagement end and a shaft end, the engagement end positionable about the tubular, the shaft end having the receptacle extending therein.

17. The ram assembly of claim 1 , wherein a portion of the at least one block groove extends through an outer surface of the ram block and into the receptacle.

18. The ram assembly of claim 1 , wherein the at least one block groove extends into a surface of the ram block to receive a portion of the at least one connector, wherein the at least one shaft groove extends into a surface of the ram head to receive another portion of the at least one connector.

19. The ram assembly of claim 18 , wherein an end of the at least one block groove is positionable adjacent an end of the at least one receptacle groove.

20. The ram assembly of claim 18 , wherein at least a portion of a length of the at least one block groove is positionable adjacent at least a portion of a length of the at least one receptacle groove.

21. The ram assembly of claim 18 , wherein the at least one receptacle groove extends through an outer surface of the ram block.

22. The ram assembly of claim 18 , wherein the at least one receptacle groove extends through a surface of the ram block within the receptacle.

23. A blowout preventer for receiving a tubular of a wellbore, comprising:

a body having a hole therethrough for receiving the tubular and at least one channel therethrough;

at least one ram assembly, each of the at least one ram assembly positionable in a corresponding at least one channel, the at least one ram assembly comprising:

a ram block disposable through the blowout preventer and positionable in sealing engagement about the tubular, the ram block having a receptacle and at least one block groove;

a ram shaft for selectively extending and retracting the ram block, the ram shaft having a ram head receivable in the receptacle, the ram head having least one shaft groove corresponding to the at least one block groove;

a ram connector for operatively connecting the ram head to the ram block in the receptacle, the ram connector comprising at least one shear connector disposable through a surface of the ram block and the receptacle, the ram connector correspondingly receivable in the at least one block groove and the at least one shaft groove whereby the ram shaft is releasably securable to the ram block; and

at least one actuator for selectively activating the at least one ram assembly.

24. The blowout preventer of claim 23 , further comprising a controller.

25. The blowout preventer of claim 23 , further comprising a remote operated vehicle.