Abstract: A fluid actuated pumping system for producing fluid from a subsurface reservoir through a wellbore communicating therewith. A conduit extends from the surface, downhole to the pump. The pump includes an inner piston reciprocatingly received within an inner barrel, an annular piston reciprocatingly received within an outer barrel, and energy storage means connected to the pistons by which energy is stored when one of the pistons is forced to move downhole. The inner piston divides the inner barrel into an upper and lower chamber, and check valve means associated therewith enables reciprocation of the piston to cause one way flow to occur into the lower chamber, and from the lower chamber into the upper chamber, where the liquid is lifted through the conduit and to the surface of the ground. The conduit is also flow connected to the annular piston so that when fluid pressure is applied thereto, both pistons are forced in a downhole direction to store energy.

Abstract: A pipe thread connector of resilient deformable material has a sleeve or tubular shape with radial ribs projecting from the sleeve. The protector is driven upon the threads of the pipe and the geometric configuration of the sleeve changes because the sleeve is bent between the ribs. This bending keeps the ribs in tight resilient contact with the threads.