James A. Klotz, The Pure Oil Company
The paper presents the results of a study of dynamometer cards and pumping units of different dimensions. The purpose of the study was to determine methods of reducing gear box torque. Generally, this torque is the most expensive item in a sucker rod pumping unit installation and the use of a smaller sized gear box is almost always economically justified. The study that is reported in this paper is aimed at methods of selecting pumping unit dimensions and counterweights so that the smallest possible gear box torque is developed. The study has been made using typical dynamometer cards to reflect typical rod loadings. A mechanical device was used to digitize the dynamometer cards: then a computer program was used to calculate gear box torque for different kinds of pumping units.