Modeling Forces on a Beam-Pump System During Pumping of Highly Viscous Crude

In previous dynamic predictive models of beam-pump performance, drag forces on the rod string commonly are modeled by an input empirical drag coefficient multiplying the local rod velocity. This paper shows how forces on the rods and pump plunger can be modeled theoretically and calculated for viscous flow. Results of viscous-flow calculations to develop drag coefficients compare well with measured field data