Pump-Off Control The Average Motor Current Method

Ever since oil well pumps were first used-in their crudest form there has been a need for controlling the pump. The controlling effort has been directed at matching the pump capacity with the well capacity. This type of control has been an objective of oil producers around the world. The value of achieving this goal has changed as the importance and value of crude oil has changed. The present conditions have placed a very high value and degree of importance on the amount of fluid produced and the lifting costs necessary to produce that fluid. Many of the pumping problems that occur in the production of oil can be traced back to the lack of proper pump control. Some of these problems include gas locks, mechanical damage to the pump, rods, gear box and excessive power consumption. With rising costs, to correct the above problems proper control of pumps has become increasingly important. There has been a decrease in the amount of manpower available to track down these pumping problems, identify and correct them. Most oil-producing fields are being operated with fewer people today than they were several years ago. During the years a number of methods have been tried in an effort to properly control pumping wells. These methods fall into two basic categories-fluid production measurement and load measurement. Various types of equipment have been developed during the last 20 years in order to properly control pumping oil wells. Some of the design and equipment met with varying degrees of success while other equipment and design met with total failure to meet the desired objective. This paper considers some of the drawbacks of previous developments; and discusses at length the development of the average motor current method of controlling oil well pumps. Following the development of this method complete field and laboratory tests were run over an extended period of time to prove the method. Conclusions reached as a result of the design and testing program are stated in the Conclusions section of this paper.