Apparatus and method for inserting or removing a string of tubulars from a subsea borehole

• US 20030019636A1
• Filed: 07/03/2002
• Published: 01/30/2003
• Est. Priority Date: 01/18/2001
• Status: Active Grant

• Current Assignee: Weatherford Technology Holdings, LLC (Weatherford International PLC)
• Original Assignee: Weatherford/Lamb Incorporated (Weatherford International PLC)
• Inventors: Robichaux, Dicky
• Granted Patent: US 6,814,140 B2
• Time in Patent Office: Days
• US Class Current: 166/380
• CPC Class Codes: E21B 19/002 specially adapted for underwater drilling E21B19/09, E21B19/143 take precedence
• CPC Class Codes: Y02E 30/10 Nuclear fusion reactors

Abstract

Apparatus and method for inserting or removing a string of tubulars from a subsea borehole, comprising:

a first, lower, gripping mechanism locatable subsea in the vicinity of the subsea borehole, the first gripping mechanism being capable of gripping a portion of the string of tubulars;

a second, upper, gripping mechanism locatable subsea in the vicinity of the subsea borehole, the second gripping mechanism being capable of gripping a portion of the string of tubulars;

wherein the first and second gripping mechanisms are moveable with respect to one another; and

a movement mechanism which, when actuated, moves one of the first and second gripping mechanisms with respect to the other of the first and second gripping mechanisms, such that the string of tubulars is inserted into or removed from the subsea borehole.

Claims

1. An apparatus for inserting or removing a string of tubulars from a sub-sea borehole, the apparatus comprising:

a first, lower, gripping mechanism locatable subsea in the vicinity of the subsea borehole, the first gripping mechanism being capable of gripping a portion of the string of tubulars;

a second, upper, gripping mechanism locatable subsea in the vicinity of the subsea borehole, the second gripping mechanism being capable of gripping a portion of the string of tubulars;

wherein the first and second gripping mechanisms are moveable with respect to one another; and

a movement mechanism which, when actuated, moves one of the first and second gripping mechanisms with respect to the other of the first and second gripping mechanisms, such that the string of tubulars is inserted into or removed from the subsea borehole.

2. An apparatus as claimed in claim 1 wherein the first gripping mechanism is lower than the second gripping mechanism.

3. An apparatus as claimed in claim 2 wherein the first gripping mechanism is adapted to be substantially stationary with respect to the mouth of the subsea borehole, and the second upper gripping mechanism is moveable with respect to the first gripping mechanism.

4. An apparatus as claimed in any of claims 1 to 3 wherein the movement mechanism comprises a jacking mechanism including a piston cylinder and a piston located within the piston cylinder, and one of the first and second gripping mechanisms is secured to the piston and the other of the first and second gripping mechanisms is secured to the piston cylinder.

5. An apparatus as claimed in claim 4 wherein the jacking mechanism is operable by introducing fluid into, or removing fluid from, one side of the piston within the piston cylinder.

6. An apparatus as claimed in claim 5 further comprising a fluid reservoir to introduce fluid into, or remove fluid from, one side of the piston within the piston cylinder.

7. An apparatus as claimed in claim 6 wherein the fluid reservoir comprises a high pressure fluid reservoir.

8. An apparatus as claimed in claim 6 or claim 7 wherein the fluid reservoir is locatable subsea.

9. An apparatus as claimed in claim 8 wherein the fluid reservoir is disposed in close proximity to the jacking system.

10. An apparatus as claimed in any of claims 4 to 9 wherein the jacking mechanism and first and second gripping means are locatable vertically above a subsea equipment package.

11. An apparatus as claimed in claim 10 wherein the jacking mechanism and first and second gripping means are locatable in line with the subsea equipment package.

12. An apparatus as claimed in any of claims 1 to 11 further comprising a make up/break out mechanism which is capable of adding a tubular to or removing a tubular from the string.

13. An apparatus as claimed in claim 12 comprising a handling mechanism adapted to deliver a tubular into, or remove a tubular from, the make up/break out mechanism.

14. An apparatus as claimed in claim 12 or claim 13 further comprising a compensation mechanism to compensate the make up/break out mechanism for movement of a vessel in the sea.

15. An apparatus as claimed in claim 14 wherein the compensation mechanism is adapted to compensate for movement of the vessel in a direction parallel to the axial direction of the string, such that the string may be substantially continuously inserted into or removed from the borehole.

16. An apparatus as claimed in claim 10 wherein the make up/breakout mechanism further comprises a pair of vertically spaced tongs which are adapted to selectively grip tubulars.

17. An apparatus as claimed in claim 16 wherein the uppermost tong is adapted to impart rotation to a tubular.

18. An apparatus as claimed in any of the preceding claims further comprising a riser into which an upper-end of a string is insertable at a vessel.

19. An apparatus as claimed in claim 18 wherein the lower end of the riser is sealable with respect to the sea.

20. An apparatus as claimed in any of claims 4 to 19 further comprising a control system to control actuation of the first and second gripping mechanisms.

21. An apparatus as claimed in claim 20 wherein the control system is adapted to control the jacking mechanism.

22. An apparatus as claimed in claim 7 or claim 8 wherein the fluid reservoir is chargeable from a pump located on a vessel.

23. A method of inserting or removing a string of tubulars from a sub-sea borehole, the method comprising:

providing a first gripping mechanism subsea in the vicinity of the subsea borehole, the first gripping mechanism being capable of gripping a portion of the string of tubulars;

providing a second gripping mechanism located subsea in the vicinity of the subsea borehole, the second gripping mechanism being capable of gripping a portion of the string of tubulars;

wherein the first and second gripping mechanisms are moveable with respect to one another;

providing a movement mechanism which is capable of moving one of the first and second gripping mechanisms with respect to the other of the first and second gripping mechanisms; and

actuating the movement mechanism such that the string of tubulars is inserted into, or removed from, the subsea borehole.

24. A method as claimed in claim 23 wherein the first gripping mechanism is lower than the second gripping mechanism.

25. A method as claimed in claim 23 or claim 24 wherein the first gripping mechanism is substantially stationary with respect to the mouth of the subsea borehole, and the second, upper, gripping mechanism is moved with respect to the first gripping mechanism.

26. A method as claimed in claim 25 wherein the second, upper, gripping mechanism is operated to grip the string of tubulars whilst the movement mechanism is actuated.

27. A method as claimed in claim 26 wherein the first, lower, gripping mechanism is not actuated such that the first, lower, gripping mechanism does not grip the string of tubulars.

28. A method as claimed in claim 27 wherein the first, lower, gripping mechanism is operated to grip the string of tubulars when the second, upper, gripping mechanism is not operated to grip the string of tubulars.