B.L. Wilson and Donn Brown, Centrilift

The performance of the centrifugal pump used in Electrical Submersible Pumps (EPS) is significantly degraded by the presence of gas in the fluid. This greatly reduces the applicability of the pump. Rotary separators, separating devices that used the pump shaft rotation to force the gas from the liquid were developed over twenty five years ago. In situations where even the rotary separator could not remove enough gas form the fluid, tandem or stacked rotary separators were often used.Improved models of rotary gas separators have been developed and introduced. In the development of the new separators, a large body of information was developed on the mechanism involved in the rotary separation. Parts of the lessons learned in the development of these new separators indicate that a tandem separator may be of little if any benefit to downhole gas separation.This paper reports on gas separator testing performed in a high pressure gas test loop. This testing concentrated on the possibility of benefit of tandem configuration on the new style gas separators. It examines and reports on where the benefits of tandems may occur.This information will be beneficial in designing and selection ESP systems in gassy applications.