Abstract: The invention generally concerns a submersible well pumping system comprising an axially elongated housing having a diameter less than the bore hole of the well, a multi-chamber hydraulically driven diaphragm pump, suspended in the well. The pump is driven by a self-contained, closed hydraulic system, activated by an electric or hydraulic motor. The flow of working fluid into and out of the working fluid sub-chambers is controlled by a two state main valve with a means to insure the main valve is completely switched, in turn controlled by a control valve which senses the differential pressure across the working diaphragm and generates a hydraulic signal to change the state of the two state main valve, typically when either diaphragm reaches the top of the pumping stroke. Singly or in combination, the means to assure the main valve is completely switched between the two states is an energy storage device, hysterisis in the control valves and or a two position latch the main valve.

Abstract: The invention generally concerns an arrangement of a low volume submersible pump connected to a downhole gravity type oil-water separator. The low volume submersible pump is electrically powered using a flexible electrical cable that connects between the pump and electric power located at the ground surface. The low volume submersible pump is typically a positive displacement pump such as a piston pump or a hydraulically driven diaphragm pump but could be a centrifugal pump if the volumes produced are compatible with this method. The separator is located above or below the pump and is defined by an enclosed, pressure-tight volume created by a separate container or by two or three downhole packers. Located in the separator is a control valve that regulates the flow of oil and water from the separator to discharge tubes connected to the surface or to additional downhole apparatus.

Abstract: The invention generally concerns a submersible well pumping system comprising an axially elongated housing having a diameter less than the bore hole of the well, a multi-chamber hydraulically driven diaphragm pump, suspended in the well. The pump is driven by a self-contained, closed hydraulic system, activated by an electric or hydraulic motor. The flow of working fluid into and out of the working fluid sub-chambers is controlled by a two state snap-acting valve, in turn controlled by a control valve which senses the differential pressure across the working diaphragm and generates a hydraulic signal to change the state of the two state snap acting valve, typically when either diaphragm reaches the top of the pumping stroke. Singly or in combination, reliable operation of the two state snap acting valve is assured by adding an energy storage device, hysteresis in the control valves and/or a two position latch on the main valve.

Abstract: A single structure to accomplish the suspension of a submersible pump and all associated loads, the conveyance of the pumped fluid from the pump to the surface, and the conveyance of electrical power from the surface to the submersible pump is disclosed. The system comprises three individual elements that are assembled just before installation into the casing and are immediately disassembled when removed from the casing: a mechanical suspension means to bear the mechanical loads, a flexible tubular conduit to convey the fluid from the pump to the surface, and an electrical cable to convey electrical power from the surface to the pump. A method to quickly and economically assemble and disassemble these elements as they are installed or removed from the casing is also disclosed.