Downhole pump speed control

Abstract From the Canadian patent

This is a method and apparatus for controlling a downhole hydraulically actuated pump. Two fluid flow monitoring means generate signals which are a function of the power fluid flow rate to the downhole pump and the return fluid flow rate from the well. An automatic controller causes the power fluid flow rate to be maintained essentially directly proportional to the return flow. Thus the power fluid flow is, not varied in the opposite direction of any change in return flow to maintain the return fluid flow constant but conversely, is changed in a, manner which will tend to accentuate any changes in the return fluid flow.