Gabor Takacs, Technical University of Miskolc, Hungary
The author developed a computerized technique for sucker rod system design that attains the pumping mode with the lifting efficiency being at a maximum. This optimum pumping mode gives the most economical combination of plunger size, stroke length and pumping speed. The proposed design procedure applies to conventional pumping units and assures minimum energy usage for the production of the required liquid rate to the surface. The method presented in this paper involves designing of the rod string for each pumping mode used in the process of selecting the optimum mode. This is an important new feature, compared to previous investigations that relied on published taper lengths. The determination of pumping parameters (plunger stroke length, pumping loads, etc.) is affected by the physical characteristics of the rod string. However, string design requires the knowledge of the pumping mode: plunger size, stroke length, pumping speed. Therefore, the selection of an optimum pumping mode is an iterative process, for which a detailed solution is given in the paper.