Maston L. Powers, Conoco Inc
Power consumption of an electric submersible pump installation may be categorized into three components, the energy required to perform useful work which is equivalent to the net hydraulic load divided by the product of pump and motor efficiencies, the energy absorbed by tubing friction which is equal to the dissipated hydraulic energy divided by the efficiency product, and power cable electrical losses. An improved design technique is presented which brings the two preceding categories of energy loss into economic perspective. The interrelated effects of tubing friction, voltage drop and motor voltage on ESP power consumption are demonstrated, as is the degree of desirability for using a motor of the highest available voltage. An equation is developed for calculating power consumption for combinations of tubing size, power cable size and motor voltage, which is useful in making economic evaluations of alternatives. Variations of power consumption are illustrated graphically for various combinations of tubing size, power cable size and motor voltage. Also illustrated is the effect of the nature of a specific net hydraulic load, i.e. the product of rate, lift and specific gravity. Practical examples utilizing the design techniques herein developed are presented and comparisons are made to designs based on common practice.