Oil well bore hole bottom pump - is operated from top of bore by borehole gas

摘要

The pump has a working cylinder containing a reciprocating piston. A balance cylinder above the working cylinder contains a piston fixed to the piston rod of the working piston. The piston rod is extended downwards to work the pump at the bottom of the borehole. Gas rising from the borehole enters a five way valve which directs it to either the under or the upper side of the working piston. Gas released from the other side of the piston is discharged through the five way valve into the gas supply line. The five way valve piston is moved by pressure from relief valves in the top of the balance cylinder and bottom of the working cylinder.