Gabor Takacs, University of Miskolc, Hungary
On average, two-thirds of the world's oil wells are produced by sucker rod pumping installations. Therefore, it is of utmost importance to ensure that these systems work at their peak efficiencies. Thus, calculating the energy efficiency of sucker-rod pumping is a very important task of the production engineer. To accomplish this task, one has to define the in-, and output powers of the system and the different kinds of losses occurring in the various parts of the downhole and surface equipment. A review of the literature on the subject revealed that the useful power of the sucker rod pump is calculated by a widely accepted formula that gives inconsistent results. The formula, of which several variants are known, predicts different powers under the same conditions on the same well if the wellhead pressure is varied. Since this behavior does not allow the comparison of different scenarios.