Abstract: A sub-sea mud pump system includes a plurality of pump units, and each pumping unit includes a plurality of pumping elements. Each pumping element includes a pressure vessel with a first and a second chamber, a separating member between the first and second chambers, a measurement device adapted to measure the volume of at least one of the first and second chambers, a hydraulic inlet control valve and a hydraulic outlet control valve coupled to the first chamber, a mud suction valve and a mud discharge valve coupled to the second chamber. The first chamber is hydraulically coupled to receive and discharge a hydraulic fluid, and the second chamber is hydraulically coupled to receive and discharge a drilling fluid. The separating member is adapted to move within its the pressure vessel in response to a pressure differential between the first and second chambers. The pump system also includes a hydraulic control unit adapted to control the plurality of pump units.

Abstract: A sub-sea mud pump system includes a plurality of pump units, and each pumping unit includes a plurality of pumping elements. Each pumping element includes a pressure vessel with a first and a second chamber, a separating member between the first and second chambers, a measurement device adapted to measure the volume of at least one of the first and second chambers, a hydraulic inlet control valve and a hydraulic outlet control valve coupled to the first chamber, a mud suction valve and a mud discharge valve coupled to the second chamber. The first chamber is hydraulically coupled to receive and discharge a hydraulic fluid, and the second chamber is hydraulically coupled to receive and discharge a drilling fluid. The separating member is adapted to move within its the pressure vessel in response to a pressure differential between the first and second chambers. The pump system also includes a hydraulic control unit adapted to control the plurality of pump units.

Abstract: The invention is a subsea pump that includes pumping elements, each pumping element including a pressure vessel with a first and a second chamber therein and a separating member disposed between the first and second chambers. The first and second chambers are hydraulically connected to receive and discharge a hydraulic fluid and a drilling fluid, respectively. The separating member moves within the pressure vessel in response to a pressure differential between the first and second chambers. A hydraulic power supply is arranged to pump the hydraulic fluid to the first chamber of each of the pumping elements. A valve assembly is hydraulically coupled to the first chambers of the plurality of pumping elements and to the hydraulic power supply. Volume measurement devices are arranged to measure volumes of each of the first chambers and the second chambers.

Abstract: The invention is a subsea pump that includes pumping elements, each pumping element including a pressure vessel with a first and a second chamber therein and a separating member disposed between the first and second chambers. The first and second chambers are hydraulically connected to receive and discharge a hydraulic fluid and a drilling fluid, respectively. The separating member moves within the pressure vessel in response to a pressure differential between the first and second chambers. A hydraulic power supply is arranged to pump the hydraulic fluid to the first chamber of each of the pumping elements. A valve assembly is hydraulically coupled to the first chambers of the plurality of pumping elements and to the hydraulic power supply. Volume measurement devices are arranged to measure volumes of each of the first chambers and the second chambers.