DEVICE FOR OIL RECOVERY Russian patent published in 2000 - IPC

FIELD: equipment for lifting of gassy fluid; applicable in oil and gas producing industry for withdrawal of fluid from wells with low static and dynamic levels. SUBSTANCE: device includes casing string accommodating flow string with packer and means for withdrawal of oil and water. The means is made in the form of double-stage polished cylinder with retaining ring and holes in its lower part. Its upper part has check valve, for instance, of ball type. Accommodated in cylinder is double-stage plunger whose upper and lower parts have inclined passage channels for oil and water. Located in plunger cavity is valve with centralizer, spring in upper part, upper and lower polished cylindrical working surfaces of different section. Valve is open with plunger moving downward. Its lower part is made with possibility of resting on retaining ring and shutting off fluid entering hollow of flow string. EFFECT: excluded additional source of power and simplified mounting of device. 1 dwg