Patent ID: 9291036
Filing Date: 2016-03-22
CPC Classification: E21B,F04B

Claim Text:
1. A method of providing a flow of pressurized fluid from a subsea accumulator to operate a subsea blowout preventer stack having at least one ram blowout preventer, comprising: discharging the subsea accumulator to drive one or more motors, driving one or more variable displacement pumps by said one or more motors, varying the displacement of said one or more variable displacement pumps to provide a flow rate which is inversely proportionate to a pressure required to operate said subsea blowout preventer stack having at least one ram blowout preventer and wherein the pressure to operate the at least one ram blowout preventer is lower at a start of a stroke and the pressure to operate the at least one ram blowout preventer is higher at an end of the stroke of the at least one ram blowout preventer whereby the pressurized fluid from the subsea accumulator is fully utilized rather than throttled and discarded.