Coaxial progressive cavity pump

Abstract

This invention relates a progressive cavity pump with a central feed-through for supplying steam, gas or liquids to the supply side of the pump. For the oil industry this invention enables single well stimulation. Steam can be supplied from the surface to the production zone or below through the central feed-through, heating or pressurizing oil and the surrounding formation, and facilitating production. In heavy oil fields solvents can be pumped down as well. Oil can be pumped up by the progressive cavity pump through the annulus of the connecting coaxial pipe.

1 . A progressive cavity pump consisting of in essence one axially uniform rotor of oval shape and sets of two rockers with straight-edged shape and housing, with an isolated cavity through the rotor connecting both sides of the pump, to be used for supplying gas or liquid to the supply side of the pump. 
     
     
         2 . A progressive cavity pump consisting of in essence one axially uniform rotor of oval shape and two rockers with straight-edged shape and one housing, with an isolated cavity through the rotor connecting both sides of the pump, to be used for supplying gas or liquid to the supply side of the pump. 
     
     
         3 . A progressive cavity pump of  claim 1  or  2 , where the shape of the rotor changes in axial direction to allow for compression or decompression.