Abstract: Pressure-balanced accumulator apparatus for use in subsea operations is disclosed which comprises a housing and an accumulator within the housing at the first end of the housing. The accumulator has first and second chambers that are hermetically sealed from one another, with a pressurized gas in the first chamber and a pressurized fluid in the second chamber. A third chamber in the housing abuts the accumulator and contains silicon oil fluid. A movable piston is located within the housing proximate the second end of the housing. Ambient pressure is communicated to one end of the piston, and ambient pressure plus the pressure in the second chamber is communicated to the second end of the piston. The cross-sectional areas of the two ends of the piston are selected to optimize the pressure at which the piston begins to expel fluid from the second chamber.

Abstract: A booster pumping system is disclosed for producing hydrocarbons from a subsea production well. The booster pumping system includes: (1) a submersible pump hydraulically connected to the production well to provide energy to the hydrocarbon flow and boost production to another destination such as a subsea production facility or the surface via a riser; (2) an inlet conduit to receive the flow from the production well and isolate the flow from the dummy wellbore and direct the flow to the intake of the pump; and (3) a motor exposed to the dummy wellbore to drive the pump. The dummy wellbore may be flooded or circulated with seawater to cool the motor.