METHODOLOGY FOR EVALUATING PARAMETERS OF THE ELECTRICAL COMPLEX «CABLE LINE — INDUCTION MOTOR» BASED ON POWER CONSUMPTION BALANCE
Authors:   Gazprom transgaz Tomsk LLC, Rakov Ivan V. 
Published: December 2023

Relevance In the Russian Federation, 82 % of oil is produced using Electric Submersible Pumps (ESP), while only 63 % of wells are equipped with such pumps. Since more than half of the operating wells are equipped with ESP, developing methods to reduce operating costs for these wells is a rational and logical allocation of human, material, and financial resources. One method to increase the profitability of oil production from low- and medium-flow rate wells is to transition a well equipped with ESP from continuous operation to intermittent operation, specifically cyclic operation. Intermittent operation reduces energy consumption by up to 40 % and increases oil production by 3 % due to partial gravitational separation of the produced fluid during accumulation. However, the negative effect of transitioning to intermittent operation is reflected in the reduction of the average runtime before failure due to a decreased ESP hydroprotection resource, accelerated wear of the pump unit thrust bearings, and intermediate radial bearings. The cause of these negative effects is the increased vibration level during intensive startup. One way to address these issues is transitioning from the existing scalar open-loop control system to a vector sensorless control system for the ESP. To implement such a system, it is necessary to obtain information about the vector of the ESP state variables. A promising approach to obtaining information about the ESP state involves creating observers based on explicit mathematical models. To create an observer for the state variables, mathematical models for each component of the studied system must be developed and combined into a unified system. When measuring currents and voltages at the output of the step-up transformer, the studied system will be an electric complex «Cable Line — Induction Motor». To implement this observer, it is necessary to determine the parameters of the equivalent circuit of the studied complex. Based on the above, developing a methodology for identifying the parameters of the equivalent circuit of the electric complex «Cable Line — Induction Motor» when measuring currents and voltages on the surface is a timely and relevant task. Solving this task will create prerequisites for the implementation of a vector control system for the ESP, increasing the reliability of the ESP during intermittent operation, and consequently, increasing the profitability of oil production from low- and medium-flow rate oil wells. Aim of research To develop and experimentally confirm the effectiveness of a methodology for assessing the parameters of the electric complex «Cable Line — Induction Motor» based on the balance of consumed power. Research methods Analysis of literary sources, system analysis, mathematical modeling, experimental research. Results The effectiveness of the methodology for assessing the parameters of the electric complex «Cable Line — Induction Motor» based on the balance of consumed power has been experimentally tested and confirmed.