Offshore drilling rig comprising an anti-recoil system
AssigneeMaersk Drilling A/S
InventorWilliam James McBeath
Life of this patent
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Abstract
Disclosed herein are embodiments of an offshore drilling rig comprising: a drill floor (107) defining a well center (123); a hoisting system configured to advance a tubular string (128) downwards through the well center (123) and to the seafloor (124) and to apply a lifting force to a tubular string (128) extending through the well center (123) and to the seafloor (124), the lifting force being large enough to support at least a major part of an apparent weight of the tubular string (128); and an anti-recoil system (218) configured to cause, in case of a sudden reduction of a load suspended from the drilling rig, the hoisting system to raise the tubular string (128) while preventing damage to the hoisting system.
Claims21
An offshore drilling rig comprising:
- a drill floor defining a well center;
- a hoisting system configured to advance a tubular string downwards through the well center and to the seafloor and to apply a lifting force to a tubular string extending through the well center and to the seafloor, wherein the hoisting system is a hydraulic hoisting system comprising one or more hydraulic hoisting cylinders;
- and
- an anti-recoil system configured to cause, in case of a sudden reduction of a load suspended from the drilling rig, the hoisting system to raise the tubular string in a controlled fashion;
- wherein the anti-recoil system is operationally connected to the one or more hydraulic hoisting cylinders.
A method of operating an offshore drilling rig, the drilling rig comprising a drill floor defining a well center, a hoisting system configured to raise and/or lower a tubular string through the well center, and an anti-recoil system configured to cause, in case of a sudden reduction of a load suspended from the drilling rig, the hoisting system to raise the tubular string while preventing damage to the hoisting system;
- wherein the method comprises:
- suspending, from the hoisting system, a high-pressure tubular string extending through the well center and downwards to the seafloor;
- detecting a sudden reduction of a load suspended from the hoisting system;
- controlling the hoisting system to raise high pressure tubular string while preventing damage to the hoisting system;
- wherein the high-pressure tubular string, when sudden reduction of the suspended load is detected, is raised by controlling fluid flow between a fluid reservoir of the anti-recoil system and the one or more hydraulic hoisting cylinders of the hoisting system.
Dependencies are inferred from the claim text.