Paper: Diagnostic Analysis of Deviated Rod-Pumped Wells

Diagnostic methods and programs for rod pumping commonly assume that the wellbore is vertical. Applying these methods to deviated wells will result in distortions and inaccuracies when calculating the down-hole pump card. This paper describes a new method for analyzing pumping efficiencies in deviated wells. The method requires a deviation survey for the 3-D borehole trajectory that incorporates the dogleg effect (rod/tubing drag forces) into the solution of wave equation. The program is applicable to wells with bare rods, molded-on rod guides, and wheeled-rod guides or a combination of these. Real examples are shown to compare results from both programs. The deviated program improves the accuracy of the pump card and the card is easier to interpret. Thus, the producing pressure and pump displacement rate based on the pump card are more precise. In addition, the deviated diagnostic program can generate data that can be used to improve the accuracy of the deviated predictive program.