Abstract: Method and apparatus for detecting problems in sucker-rod well pumps and for determining which type of problem occurs. A first transducer provides a signal representative of the load on a sucker-rod string and a second transducer provides a signal representative of the sucker-rod position. The load signal and the position signal are used to generate a dynagraph of rod load vs. rod position with the pump working normally. A working dynagraph is continually compared with the normal dynagraph and a working load signal is continually compared with a normal rod load signal to detect problems in the pumping system and to determine the type of problem detected if one does develop.

Abstract: Methods and apparatus for detecting fluid pound in a sucker-rod oil well, using maximum and minimum values of sucker-rod position and of sucker-rod load to calculate a reference position and a selected load value. The apparatus automatically calculates the reference position and the selected load value according to the characteristics of the well and of the well pumping equipment. When the sucker-rod moves downward to the reference position, the actual load value is checked against the selected value and in one embodiment of the invention a warning signal develops when the amount of the load exceeds the previously selected load quantity. In another embodiment a warning signal develops when the rate of change of the load is at a maximum below the reference position. In a third embodiment a warning signal develops when a minimum rate of change of the load occurs below the reference position.

Abstract: Method and apparatus for recording and subsequent playback of selected dynagraphs for wells employing sucker-rod pumping units to determine well faults which cause well shutdown. Calibration data from well monitoring equipment is stored in a first "endless tape" type of memory during calibration of the well and operation data from the monitoring equipment is stored in a second "endless tape" memory during well operation. After well shutdown the stored data can be retrieved and the operation data stored immediately prior to well shutdown compared with calibration data to determine what type of fault caused well shutdown.