Heave compensation system for assembling a drill string

Patent metadata

Field	Value
Publication number	US-2017183923-A1
Application number	US-201715457721-A
Country	US
Kind code	A1
Filing date	Mar 13, 2017
Priority date	Dec 19, 2013
Publication date	Jun 29, 2017
Grant date	—

Abstract

A method of deploying a jointed tubular string into a subsea wellbore includes lowering the tubular string into the subsea wellbore from an offshore drilling unit. The tubular string has a slip joint. The method further includes, after lowering, anchoring a lower portion of the tubular string below the slip joint to a non-heaving structure. The method further includes, while the lower portion is anchored: supporting an upper portion of the tubular string above the slip joint from a rig floor of the offshore drilling unit; after supporting, adding one or more joints to the tubular string, thereby extending the tubular string; and releasing the upper portion of the extended tubular string from the rig floor. The method further includes: releasing the lower portion of the extended tubular string from the non-heaving structure; and lowering the extended tubular string into the subsea wellbore.

First claim

1 . A method of deploying a tubular string from an offshore drilling unit into a subsea wellbore, comprising:
anchoring a lower portion of the tubular string below a slip joint to a non-heaving structure; while the lower portion is anchored:
supporting an upper portion of the tubular string above the slip joint with a spider of the offshore drilling unit;
after supporting, adding one or more joints to the tubular string above the spider, thereby extending the tubular string; and
after adding, releasing the upper portion of the extended tubular string from the spider; and
releasing the lower portion of the extended tubular string from the non-heaving structure.

2 . The method of claim 1 , wherein the non-heaving structure is a casing string cemented in the subsea wellbore.

3 . The method of claim 2 , wherein:
the tubular string further has an anchor disposed below the slip joint, and the lower portion is anchored by setting the anchor against the casing string.

4 . The method of claim 3 , wherein the tubular string further has a setting tool disposed between the slip joint and the anchor.

5 . The method of claim 4 , wherein:
the tubular string is rotated during lowering, rotation is ceased before anchoring, the setting tool has a controller and a tachometer, and the controller sets the anchor in response to detection of cessation of rotation using the tachometer.

6 . The method of claim 4 , wherein the setting tool comprises an antenna.

7 . The method of claim 1 , wherein the non-heaving structure is one of: a marine riser, a lower marine riser package, and a blowout preventer (BOP) stack.

8 . The method of claim 6 , wherein:
the slip joint is a tensioner, the non-heaving structure has a drill string gripper, and the portion is anchored by engaging the gripper with the drill string.

9 . The method of claim 8 , wherein:
the tubular string is lowered through the marine riser and an upper marine riser package having a rotating control device (RCD), the method further comprises closing a BOP against the drill string, and the tensioner is operated by pressurizing the riser between the RCD and the closed BOP.

10 . The method of claim 8 , wherein:
fluid is circulated through the tubular string during lowering, the drill string further has a flow sub, and the tensioner is operated by engaging a clamp with the flow sub to maintain circulation during anchoring.

11 . The method of claim 8 , further comprising engaging the gripper with the drill string in response to detection of a well control event.

12 . The method of claim 8 , wherein:
the tubular string is a drill string having a drill bit at a bottom thereof, and fluid is circulated through the drill string and the drill bit is rotated during lowering, thereby drilling the wellbore.

13 . A drill string gripper, comprising:
a plurality of rams, each ram radially movable between an engaged position and a disengaged position and having a die fastened to an inner surface thereof for gripping an outer surface of a tubular, the rams collectively defining an annular gripping surface in the engaged position; a housing having a bore therethrough and a cavity for each ram and flanges formed at respective ends thereof; a piston for each ram, each piston connected to the respective ram and operable to move the respective ram between the positions; a cylinder for each ram, each cylinder connected to the housing and receiving the respective piston; and a bypass passage formed though one or more of the rams, the passage operable to maintain fluid communication between upper and lower portions of the housing bore across the engaged rams.

14 . A heave compensation system for assembling a tubular string, comprising:
the drill string gripper of claim 13 for assembly as part of a marine riser; and a tensioner for assembly as part of the tubular string.

15 . A method of deploying a tubular string into a subsea wellbore, comprising:
lowering the tubular string into the subsea wellbore from an offshore drilling unit, wherein:
a blowout preventer (BOP) and drill string gripper are connected to a subsea wellhead of the wellbore, and
the drill string gripper is connected above the BOP;
detecting a well control event while lowering the tubular string; engaging the drill string gripper with the tubular string in response to detecting the well control event; and engaging the BOP with the tubular string after engaging the drill string gripper.

Assignees

• Weatherford Tech Holdings Llc

Inventors

• Bansal Ram K
• Ring Lev
• Hannegan Don M

Classifications

• E21B47/092

  by detecting magnetic anomalies · CPC title

• E21B17/01

  Risers · CPC title

• E21B23/01

  for anchoring the tools or the like (E21B23/02 - E21B23/06 take precedence; anchoring of drives in the borehole E21B4/18) · CPC title

• E21B19/06

  Elevators, i.e. rod- or tube-gripping devices · CPC title

• E21B19/16

  Connecting or disconnecting pipe couplings or joints (E21B19/20 takes precedence) · CPC title