Abstract: Methods and systems for controlling the timing of a fluid driven positive displacement pump (FDPDP) are disclosed using pump inlet pressure, flow rate and time domain control. Pressure is thus controlled at various flow rates of fluids to be pumped in subsea environments. The FDPDP includes a plurality of pressure vessels connected by piping, each vessel having two chambers. One chamber is connected to a source of fluid to be pumped and the other chamber is connected to a source of driving fluid. The methods synchronize pumping chambers that have no mechanical means to control timing between each pumping chamber. The control methods described utilize algorithms which receive feedback from the pumping system to control the pumping sequence and adapt to any parameter changes to maintain a constant range of desired pressure.

Abstract: Methods and systems for controlling the timing of a fluid driven positive displacement pump (FDPDP) are disclosed using pump inlet pressure, flow rate and time domain control. Pressure is thus controlled at various flow rates of fluids to be pumped in subsea environments. The FDPDP includes a plurality of pressure vessels connected by piping, each vessel having two chambers. One chamber is connected to a source of fluid to be pumped and the other chamber is connected to a source of driving fluid. The methods synchronize pumping chambers that have no mechanical means to control timing between each pumping chamber. The control methods described utilize algorithms which receive feedback from the pumping system to control the pumping sequence and adapt to any parameter changes to maintain a constant range of desired pressure.