METHOD OF INTERVENTION IN A FAILED DEEP-SET SUBSURFACE SAFETY VALVE IN A DEEPWATER OR ULTRA-DEEPWATER SUBSEA WELL USING A LIGHT INTERVENTION VESSEL

摘要

A method of intervention in a failed deep-set tubing-retrievable subsurface safety valve disposed in a deepwater or ultra-deepwater subsea well uses a deep-set wireline-retrievable subsurface safety valve that may be deployed via wireline into the failed deep-set tubing-retrievable subsurface safety valve. The deep-set wireline-retrievable subsurface safety valve has a closure actuation mechanism that is disposed below the closure device. In addition, the closure actuation mechanism includes a pressure-balanced piston that is exposed to wellbore fluids on both distal ends of the piston, thereby allowing the piston to actuate the closure device in deepwater and ultra-deepwater wells with significant hydrostatic head in the control line. Advantageously, the method does not require re-completion of the well and a light intervention vessel may be used as the platform for performing the intervention, rather than a conventional drilling rig or platform, substantially reducing non-productive down-time, lost profits, and costs associated with resuming production.