By J. F. Lea, Amoco RPM/EPTG, Lynn Rowlan, Amerada Hess,
and Jim McCoy, Echometer Company
The purpose of artificial lift equipment is to do work by adding extra power to the produced fluid so that the fluid will flow to the surface. The power added lifts the produced fluid to the surface at a rate higher than the well power can provide. The power is added to the fluid by some type of downhole pump or gaslift. "Artificial Lift Efficiency" is a way to calculate how effective a particular type of lift equipment is in adding power to lift the fluid. In the literature there are many definitions of artificial lift power efficiency, but there is not one particular accepted equation. Reference 1 lists and reviews a number of references, which provide a variety of expressions calculating artificial lift efficiency. Also this reference compares a number of ESP vs. Beam Pump wells with electrical or power efficiency. However, in the paper it is shown that the definition of efficiency that was used in that study is subject to some unexpected variations if the surface pressure or amount of gas produced through the tubing is varied. Because of this, the definitions of artificial lift efficiency are reviewed and a standard equation is recommended.