Abstract
The acoustic method with echo sounder is used to determine the annulus liquid level in the rod pumping systems installed at different onshore fields of Mehsana Asset. The limitation is difficulty in finding the pumped off well among the huge population of rod lift systems on day-to-day basis. The motor current sensor of the RTMS can be used to determine real time dynamic annulus liquid level, with five cases validating the efficacy of this innovation. The current sensor of the RTMS is the important tool in the analyzing the subsurface pump condition. Real time power in the three phases is calculated from the real time current. Power can be used to determine the torque requirements of the system. For counterbalanced pumping unit, the net torque per pumping stroke corresponds to the buoyed weight of the sucker rods plus one half of the fluid load. The annulus liquid level is calculated from the pump intake pressure. The paper will describe the mathematical model with assumptions to determine the annulus liquid level from the real time current. The annulus dynamic liquid levels were determined through the mathematical model. This model will also provide real time fluid load and pump intake pressure to the operator for balanced pumping units having current withdrawal above 20A. The maximum difference in annulus liquid level between field equipment and mathematical model is around 75m with reasonable accuracy of 90%. Accuracy for pumped off wells increases to 96%. Accuracy will further improve with calibration of motor current sensors and determination of the surface unit operating parameters.
