Abstract: This invention provides the structure and operation of a double-acting, deep-well fluid extraction pump assembly which includes a power piston housed on top of a pumping piston along with a power control system. The pumping piston has a dynamic, reciprocating, bi-directionally self-cleaning, suction filter and houses poppet-type, uni-directional, fluid flow control valves that control the inflow and outflow of extracted fluid through the pumping piston. Gland membranes and a number of double-acting, lineal, fluid motor pistons divide the power piston into pressure chambers and into fluid conduits, with the divisions conjointly providing a path for inflow of hydraulic power fluid and a path for outflow of extracted fluid. The power control system includes a four-way, directional, flow-control valve for controlling cycling frequency, a timer and a flow switch for controlling recovery periods, an unloading relief valve for controlling fluid pressure and a flow-control valve for controlling pumping speed.

Abstract: This invention features a small-enveloped (with an outside diameter of at least approximately 38 mm), single-acting, hydraulically-operated, reciprocating, deep-well, fluid-extraction pump, operable in non-straight and angular wells, and its mode of operation. The hydraulically-operated, deep-well pump, in addition to having an above-ground installation of its motor-fluid generator and of its control valving, comprises a compound, stepped piston that is reciprocably mounted within a cylinder which in turn is divided into individual pressure chambers. Hydrostatic pressure created by a hydraulic pump is selectively directed to two outlet ports to produce an overpressure in one of the outlet ports at any given instant. The overpressure in each outlet port leads to creation of overpressure in one or more pressure chambers. Imbalances in pressure among the pressure chambers result in movement of the compound, stepped piston and extraction of hydraulic-well fluid by the compound, stepped piston.