Patent ID: 9664031
Date: 2017-05-30
CPC Classifications: E21B

Claim:
1. A method, comprising: moving a polished rod of a pumping unit through a first cycle of the pumping unit using a motor; determining first pulse count values of the motor through the first cycle using a first sensor at first times, the first times being substantially equally spaced; determining first position values of the polished rod through the first cycle using a second sensor at the first times; associating the first pulse count values with respective ones of the first position values to calibrate a processor of the pumping unit; generating a reference table using the first pulse count values and the first position values obtained at the first times to show a correlation between the first pulse count values and the first position values; removing the second sensor and continuously operating the pumping unit; and determining second position values of the polished rod versus time while the pumping unit is continuously operating using the reference table in combination with data from the first sensor.