Sub-sea well intervention vessel and method
First Claim
1. A sub-sea well intervention vessel comprising a dynamically positionable tanker and direct well intervention equipment mounted on the deck of the tanker, the direct well intervention equipment including drilling equipment for underbalanced rotating or non-rotating drilling for connection to a drilling riser and a hydrocarbon liquid separator coupled to storage tanks of the tanker such that separated hydrocarbon liquids can be stored in the tanker, wherein there is provided production plant and a coupling arrangement for coupling the plant to at least one production riser that is separate from the drilling riser, the production riser being for connection to a sub-sea manifold associated with the well, thereby allowing simultaneous underbalanced drilling and production via separate risers, the drilling equipment being selectively disconnectable from the well to allow production only via the production riser.
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Accused Products
Abstract
A sub-sea well intervention vessel includes a dynamically positionable tanker and direct well intervention equipment mounted on the tanker deck. The intervention equipment includes drilling equipment for performing underbalanced drilling and hydrocarbon liquid separation. A separate production riser is provided so that simultaneous drilling and production can be performed via separate risers. The driller riser is selectively disconnectable from the well so that the tanker can be dynamically repositioned over the well. A turret mooring system is provided such that the production riser can remain in operation during repositioning about the turret. The hydrocarbon liquid separator is connected to a separator of the production plant.
18 Citations
31 Claims
- 1. A sub-sea well intervention vessel comprising a dynamically positionable tanker and direct well intervention equipment mounted on the deck of the tanker, the direct well intervention equipment including drilling equipment for underbalanced rotating or non-rotating drilling for connection to a drilling riser and a hydrocarbon liquid separator coupled to storage tanks of the tanker such that separated hydrocarbon liquids can be stored in the tanker, wherein there is provided production plant and a coupling arrangement for coupling the plant to at least one production riser that is separate from the drilling riser, the production riser being for connection to a sub-sea manifold associated with the well, thereby allowing simultaneous underbalanced drilling and production via separate risers, the drilling equipment being selectively disconnectable from the well to allow production only via the production riser.
- 20. A method for conducting offshore underbalanced drilling, whereby a dynamically positionable tanker having direct well intervention equipment mounted on its deck including underbalanced drilling equipment is dynamically positioned over a well, the drilling equipment is coupled to a drilling riser from said well in order to intervene in said well, a separate production riser is coupled to said vessel from a sub-sea manifold associated with said well and underbalanced drilling is performed simultaneously with production via the separate production riser.
Specification