Patent ID: 7500390

Claim:
A method for estimating pump efficiency of a rod pumped well, comprising: providing a rod within the well, the rod connected to a pumping unit at a first end thereof and a pump at a second end thereof, the pumping unit located at surface; reciprocating the rod within the well by the pumping unit; determining a load on the rod and displacement of the rod at a plurality of times during a single stroke of the pumping unit; utilizing the rod loads and displacements at the plurality of times to calculate at least one displacement and time near the pump; utilizing the calculated displacement and time near the pump to determine a minimum stroke (NS, feet) and maximum stroke (XS, feet); utilizing the calculated displacement and time near the pump to calculate a transfer point (TP); and calculating the pump efficiency from the minimum stroke (NS, feet), maximum stroke (XS, feet), and transfer point (TP) according to Equation (1): Pump Efficiency=100%*( TP−NS )/( XS−NS ) (1).