A.L. Podio, University of Texas, J.N. McCoy, O. Lynn Rowlan, & Dieter Becker, Echometer Co.
Dynamometer Analysis Plots allow the display of various parameters; both acquired and calculated, during a complete pumping unit stroke. At a user-specified time frequency, the polished rod load, polished acceleration, electrical motor power, and current data are acquired a during a dynamometer survey at a sucker rod lift well. Using the descriptive well information and pumping unit geometry many other parameters are calculated, such as: pump load, polished rod position, polished rod velocity, pump plunger position, pump plunger velocity, existing mechanical and electrical net gearbox torque, instantaneous SPM, and motor RPM. These calculated and acquired dynamometer parameters can be plotted, in pairs, in any combination versus any of four horizontal axis parameters; polished rod position, plunger position, elapsed time, or crank angle. Analysis of operational problems can be aided through the ability to graphically compare the various acquired and calculated data values. Frequently the standard plots of load vs. position or vs. time displayed by analysis software programs are not sufficient to trouble shoot and analyze a sucker rod lift problem. Providing a user the graphic capability to easily select and compare the different acquired and calculated parameters for a selected individual stroke, leads to better understanding and analysis of the sucker rod lift producing conditions.