The Cooper Basin is one of Australia's largest onshore resource projects. It is geographically located in central Australia in a remote and harsh area commonly known as the "Outback". On behalf of its joint venture partners, Santos operates more than 400 oil wells and 820 gas wells covering an extended operating area of approximately 12,000 square miles. A variety of artificial lift systems are used dependent on reservoir depth and fluid rate. This paper will focus on the application of Progressing Cavity Pumps (PCP) with a review of historical run life data and key lessons learned from 2004 to 2012.

Santos installed its first PCP system in 1990. The trial was considered unsuccessful as a result of a pump failure occurring within a matter of days. No further trials of a PCP system were undertaken until 2004. This second 2 well trial was able to demonstrate the operability of the PCP system by achieving run lives of 180 and 250 days. These results were encouraging enough to move forward with expanded trials in a wider range of reservoirs located in various fields.

The peak of the PCP implementation program in the Cooper Basin reached 145 installations in 2008. Unfortunately many of the applications fell outside of newly understood technical limits. Consequently a number of subsurface failures occurred which resulted in many unplanned workovers. As a result of poor PCP reliability, a change to more dependable forms of artificial lift was undertaken. The total PCP installation base has decreased to 38 systems of which 18 are operating in one particular field achieving pump run lives of 400 to 800 days.

This paper will assist operators to benchmark PCP system performance in similar light oil applications as found in the Cooper Basin. Additionally, the paper will outline a set of technical limits developed from our operating experience and lastly, it will provide a guideline to understand the risks associated with operating PCP systems in a light oil application.

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