TWO-LEVEL METHOD FOR DIAGNOSING TECHNICAL CONDITION OF SUCKER-ROD PUMPING UNITS

Abstract

Relevance. A significant number of the largest oil fields in Russia are in the final stages of development, characterized by a decrease in production volumes, increase in the share of complicated wells. Sucker-rod pump units are one of the most common methods of operating wells short-term production fund. The operation of rod pump installations in complicated operating conditions in some cases is accompanied by decrease in the turnaround time of work, increase in the specific energy and economic costs during production. In these conditions, one of the most urgent task is ensuring the cost-effective development of wells due to the timely diagnosis of the technical condition and operating conditions of pumping equipment. Objects: pumping unit operating in various operating conditions, including in the presence of complicating factors, and a wellhead dynamometer card of operation of the rig, reflecting technical condition and operating conditions of the downhole equipment. The aim of the research is to develop a new approach to diagnosing the state of rod pumping units using a dynamometer card, based on solving inverse problems of the dynamics of a rod installation. Methods: methods for numerical solution of partial differential equations for direct problems, including modeling the theoretical dynamometer cards of the rod installation; methods for solving inverse problems aimed at quantifying the parameters of the model characterizing the operation of the rod installation. Results. The authors have developed two-tier method for diagnosing the state of pumping units using a dynamometer card. The proposed diagnostic method includes: at the first level, the processing of practical dynamometer cards by the pattern recognition system and, at the second level, a quantitative determination of the consequences of faults, based on the physical laws of formation of configuration of dynamometer cards, the solution of the problem of the dynamics of a rod installation. By analyzing the configuration of dynamometer cards under various operating conditions of pumping equipment (normal operation, high gas content at the pump intake, leakage in the pump discharge valve, low plunger fit in the cylinder), the examples of solving quantitative diagnostics problems based on the developed algorithm are shown.

Keywords

• rod pump installations
• dynamometer card
• modeling of dynamometer card
• diagnostics
• intake pressure
• complicating factors
• quantitative assessment