Sucker rod pump frequency-elastic drive mode development – from the numerical model to the field test

A frequency-elastic drive mode for a sucker rod pumping system is introduced to reduce its polished rod peak loads and the total energy consumption. Numerical modeling and an extensive field test verify the concept. The frequency-elastic drive mode is a software solution for variable speed drive systems, which can be applied in the controller and does not require any hardware adjustments. The novel drive mode adjusts the set frequency, sent by the controller to the frequency converter, depending on the actual power requirements. An increase in power consumption results in a reduction of the set frequency, which is proportional to the power consumption increase. A reduction in power consumption results in the opposite effect to achieve a similar pumping speed as for regular operation. The frequency-elastic drive mode is simulated by a numerical model, which covers the entire pumping system. An extensive field test was performed to verify the concept and the numerical model. The simulation and the field test have confirmed the concept of the frequency-elastic drive mode and quantified its saving potential. The evaluation of the field test has shown that the energy-saving potential can reach five percent. In addition, a peak polished rod load reduction of up to three percent was seen. At the tested pumping system the frequency elastic drive mode under optimized parameters yields the best results in terms of total energy savings in the pumping speed range between 7 to 10 strokes per minute. A downhole system efficiency increase was seen for any pumping speed. The numerical model matches the field test data and allows the performance prediction of the novel drive mode for changed parameters and wellbore configurations without extensive field testing. The novelty of the presented paper is the concept of the frequency-elastic drive mode, which is a pure software solution for variable speed drive sucker rod pumping systems. The holistic model includes the entire pumping system and matches the field test data at remarkable accuracy.