Gas Pump – A Gas-Driven Positive Displacement Pump Artificial Lift System

Abstract

Many resource play (shale) reservoirs have been drilled with highly tortuous wells. These wells are difficult to produce in their late life when production rates and pressures decline to the point where positive displacement pumping becomes necessary. Reciprocating rod pump (RRP) systems are expensive to install and operate in these conditions. RRPs’ inherent issues with friction and wear and tear on equipment are exacerbated in these kinds of crooked wells. Gas Pump (GP) is a newly invented artificial lift system that provides the benefits of positive displacement pumping for these kinds of wells without the inherent installation costs and failure risks associated with RRP. GP uses high pressure natural gas to blow liquids out of a bottom hole accumulator chamber into the tubing (like RRP) all while isolating the reservoir from the backpressure of the column of liquid standing in the tubing, thereby enabling maximum reservoir pressure drawdown. This paper will describe the theory behind GP's technical design and mechanical application, relay the practical equipment design and testing processes used to progress the system from concept to prototype, and conclude with GP's prototype performance assessment.