Selection method modelling and matching rule for rated power of prime motor used by Beam Pumping Units

The energy consumption of prime motors used in oilfields is the one-third of the total energy consumption of beam pumping unit wells. In order to keep initiating and operating the prime motor smoothly and safely, its actual rated power is high much more than the needed. With the intention of improving the efficiency of the prime motor and decreasing the cost of rod-pumping, a set of rated power calculated methods and a set of matching templates was built up under the regarding conditions such as the changing rule of the system load, the heating of the prime motor and the overload torque in the initiate processing. The tested data indicated that, after replacing the prime motor with lower power, the active power, the inactive power and the suspended polished-rod load were all decreased substantially.