Patent ID: 6364633
Filing Date: 2002-04-02
Classification: E21B,F04B

Abstract:
A hydraulically actuated down-hole pump comprising:a vertically elongated structure formed of a plurality of axially supported outer tubes, each outer tube being internally threaded at each end, externally threaded coupling blocks interconnecting said outer tubes, at least one of said outer tubes being an engine outer tube; an engine cylinder coaxially received within said engine outer tube and of external diameter less than said engine outer tube providing an annular power fluid passageway therebetween; an engine piston within said engine cylinder; one of said outer tubes being a production outer tube in axial alignment with and connected to a lower end of said engine outer tube; a production cylinder coaxially received within said production outer tube and of external diameter less than said production outer tube providing an annular production fluid passageway therebetween; a production piston received within said production cylinder; a ported valve rod interconnecting said engine piston and said production piston; an engine valve controlling the delivery of power fluid to said power cylinder to actuate said power piston; and a production valve controlling the passage of production fluid to said production cylinders, power fluid flowing internally within the pump through said annular power fluid passageway and production fluid flowing internally within said pump through said annular production fluid passageway.