Two-Phase Flow Performance for Electrical Submersible Pump Stages

Summary Two-phase flow behavior prediction for centrifugal pumps is a difficult task because of the complexity involved in modeling multiphase flow inside turbo machines. An experimental study has been conducted at the U. of Tulsa Artificial Lift Projects (TUALP) with a 513-series, 22-stage, mixed-flow-type pump to gather data for pump performance under two-phase flow conditions. Air and water were used as the working fluids. This study differs from other experimental works because the pressure changes were recorded stage by stage. The results of previous works have been reported as an average of the intake and discharge conditions and depend on the number of stages used. Phenomena such as surging and gas locking were observed during these tests, and their boundaries have been mapped. The pressure increment and total hydraulic horsepower for the average pump, those per stage as a function of the liquid flow rate, and each gas flow rate considered are presented. The pump's average brake horsepower and efficiency also are plotted for the variables mentioned. The results indicate that average pump behavior is significantly different from that observed per stage.