(2015013) MODIFIED EVERRIT-JENNINGS CALCULATED DOWNHOLE DATA COMPARED TO MEASURED SANDIA DATA
In the case of a vertical well, the rod string can be compared to an ideal slender bar. Therefore the propagation of stress waves occurring from cyclic loading and un-loading during a pumping cycle becomes a one dimensional phenomenon.
The most accurate way of computing downhole data, is therefore by solving the one-dimensional damped wave equation. The Modified Everitt-Jennings algorithm combines finite differences with other state of the art innovative algorithms to provide precise downhole data, accurately reflecting present downhole conditions.
In the 1990’s, Sandia National Laboratories were contracted to measure actual position and load data at different depths of the rod string through a series of downhole tools.
In this paper, results from the Modified Everitt-Jennings methodology are compared to actual field measurements, captured by the Sandia National Laboratory experiment.