An Improved Technique for the Evaluation of Performance Characteristics and Optimum Selection of Sucker-Rod Pumping Well Systems

Abstract

ABSTRACT An improved method is presented for the evaluation of performance characteristics and optimum selection of sucker-rod pumping well systems. The procedure is conceptually general for all class I lever (conventional) systems and for the Mark II type of the class III lever systems. The procedure can easily be modified for any kind of special surface pumping unit. This study uses basic sucker-rod theory already presented in the literature. The new approach, however, groups the most important variables affecting the operation of a total sucker rod pumping well system (from the prime mover to the downhole pump) into eleven dimensionless numbers which are used to aid the simulation of performance characteristics and design parameters. The final results consist of design parameters for various rod size-pump depth-production rate combinations from which an optimum pumping mode is selected. The selection of the optimum pumping mode is based on an optimization criterion proposed in this paper. Based on limited specified information on a well being considered for the installation of a rod pumping system, the method presented can be used to select a total sucker rod pumping system that will optimize both production and longevity of all parts of the system. The procedure minimizes the design of incompatible parts that very frequently leads to system failures. For already existing installations, the method furnishes information on pumping speed, counter-balance weight, polished rod stroke, etc., for setting a new optimum operation.