Case History of a Successful Progressing Cavity Pump Application in an Extremely Low Pressure Environment

Abstract This paper summarizes the production history, wellbore configuration, reservoir parameters and mechanical design parameters of a progressing cavity pump application in a high productivity, extremely underpressured, partial water drive reservoir. The current reservoir pressure of approximately 50 psi has presented a unique challenge to optimizing the productivity and operating costs of the well. It was operated for many years on conventional rod pump with a history of downhole equipment failures and restricted production capability. An effort to produce the well with an electric submersible pump system was unsuccessful because of the low reservoir pressure and the limited vertical space to install equipment. A progressing cavity pumping system has been in operation for fifteen months. After seven subsurface failures in six months, several changes to the system were made that optimized the production rate and minimized downhole failures. Among these changes were installing plastic coated sucker rods, an oversized carburized rotor, and a tubing anchor and stabilizing the wellhead from vibration. The oil production rate on progressing cavity pump has increased 35 BOPD, almost 300%.