An Extended Computational Fluid Dynamics Model and Its Experimental Validation to Improve Sucker Rod Pump Operation and Design

Summary Recently, the authors proposed a novel computational fluid dynamics model to simulate the detailed fluid flow in a sucker rod pump under close-to-realistic operating conditions (Jalikop et al. 2021). The focus of this forerunner study concerns two central observations in the dynamics of the standing valve: (i) its unexpected intermediate (midcycle) closure that is potentially triggered by fluctuations in plunger speed intrinsic to any downhole pump during a pumping cycle; and (ii) its ideal, just fully open but critical state of operation is characterized by a square-root dependence of the associated critical plunger speed on the density of the ball material relative to that of the fluid. In this work, the theoretical predictions (i) and (ii) have been verified using a test rig designed to provide us with quantitative and accurate measurements of the crucial parameters needed for such a comparison. In addition, the computational model is subject to a rigorous test for its overall validation. The so-obtained experimentally validated model could be used to provide a theoretical basis for decision-making by either the design engineer or the operator, in particular when it comes to preventing issue (i) mentioned above and keeping a minimum plunger speed in the sense of circumstance (ii) above.