Improving the Estimation of a Sucker Rod Pumping Dynamometer Card Based on the Terminal Quantities of the Driving Motor

Abstract

Rod pumping systems typically require the analysis of dynamometer cards for fault diagnosis. While external instrumentation assists in obtaining these cards, it simultaneously raises monitoring costs and complexity. To address this issue, this paper introduces a parameter estimator that integrates the equivalent circuit model of an induction motor with the beam pumping unit model. We have compared the performance of two practical estimators, utilizing the terminal quantities of the driving motor as inputs. The results demonstrate surface dynamometer cards under varying operational conditions of the oil well. By augmenting the estimator's input variables, the estimated cards align more closely with the actual ones. This practical application proposes an alternative method for acquiring the surface dynamometer card, which can function as a supplementary approach in fault diagnostics and contribute to informed maintenance decisions for the pumping unit.