Sand production becomes more critical as the reservoir pressure depletes typically associated by water cut, scaling and sand production intensity. Erosion rate of Electric Submersible Pump (ESP) components tends to be ruled by pump rotating speed. Even so, strong focus on modern technological advances towards improving pump design has made ultra-high-speed ESP compatible with sandy wells.
This paper will review several case histories demonstrating the evolution of the ultra-high-speed ESP PMM (Permanent Magnet Motor) technology for over a decade. With a speed control ranging between 1,000 and 12,000 rpm, pump design and metallurgy were crucial aspects to focus on to ensure reliable operation in sandy wells. Continuous equipment analysis made during trials provided guidance to improve the design, while high-precision manufacturing techniques have made it possible to implement new solutions.
Case histories have showed high tolerance of the modern ultra-high-speed ESPs to solids in the produced fluid. Abrasion resistance is achieved with hard alloys being applied to the pump along with innovative modular pump design. As a result, ramp-up time has been reduced, with failure rate being minimized. Implemented design features enabled to declare maximum solid content for ultra-high-speed ESP at higher levels (up to 2 g/l) if compared to conventional equipment despite significantly higher nameplate speed (10,000 rpm) of the former. Successful results of the ultra-high-speed ESPs in sandy wells demonstrate a good example of integrating new technology developments into operation in harsh environment. These findings may help expand an application range of the systems traditionally considered as having relatively poor durability when exposed to sand production.
The systems studied in this paper represent a new generation of ESPs combining all the features of operation at high speed along with abrasion resistance being normally considered as incompatible with high RPM (rotation per minute). The conclusions of this paper are intended to provide advice when selecting and designing an artificial lift method.