Patent ID: 7628207

Claim:
Apparatus for use in subsea operations, which comprises: a housing comprising a generally tubular-shaped member having first and second ends; an accumulator located within the housing proximate the first end of the housing where the accumulator comprises a first chamber for receiving a pressurized gas at a first pressure and a second chamber for receiving a first pressurized fluid at a second pressure and where the first and second chambers are hermetically sealed from one another, the second chamber being in fluid communication with a subsea intervention system; a third chamber in the housing which abuts one end of the accumulator, where the third chamber contains a oil fluid and where the pressure of the oil fluid in the third chamber tracks the pressure of the pressurized fluid in the second chamber of the accumulator; a movable piston which is located within the housing proximate the second end of the housing, the movable piston having first and second ends with first and second cross-sectional areas, respectively, where the piston is movable between a first position and a second position, where the second end of the housing includes a port to permit ambient subsea pressure to impinge on the first end of the piston, where the second end of the piston contacts the third chamber, and where the cross-sectional areas of the first and second ends of the piston are selected so as to optimize the pressure in the second chamber at which the piston begins to expel fluid from the second chamber of the accumulator; and an atmospheric chamber which creates a differential pressure across the piston which permits the piston to begin to move when the force on the first end of the piston exceeds the force on the second end of the piston.