Electric Submersible Pump Optimization in the Bima Field

Abstract

ABSTRACT An oil rate increase of more than 40% in a Bima field well was observed when the number of stages in the electric submersible pump (ESP) was doubled from its original design. The high viscosity of the Bima crude is believed responsible for reducing the head generating capacity of ESPs installed in this field. This condition makes it necessary to run units with extra staging. Although this phenomenon is documented in the literature, the use of published head efficiency factors does not adequately compensate for the magnitude of the head loss. Since these correlations depend on the viscosity of the crude oil, the discrepancy may be related to the difficulties in measuring the viscosity of an oil emulsion system in the laboratory. This problem is circumvented by using downhole pressure sensors to record the head developed by the ESP in the well. The measured value is then compared to an expected value to obtain actual head efficiency. By knowing the magnitude of these efficiencies, ESPs producing from the same reservoir can be designed using a more realistic head loss correction.