Modeling the performance of progressive cavity pump under downhole conditions

Abstract

Progressive Cavity Pump (PCP) is a common artificial lift method for high viscosity liquid production. In elastomeric stator PCP, the clearance between the metal rotor and elastomeric stator prevents mechanical friction but also causes reverse flows phenomenon known as slippage. This clearance is a key parameter in modeling pump performance. Currently, existing PCP slippage models are developed for single-lobe, constant clearance, at surface operation. This study experimentally and theoretically investigates the effect of downhole condition on behaviors of elastomeric stator. An analytical model for stator deformation based on Hooke's Law and composite cylinder theory is proposed. The proposed model is coupled with a developed analytical model for PCP performance at surface conditions to introduce, for the first time, a comprehensive model applicable for multilobe PCP operating at downhole conditions. The coupled model is validated against experimental data of PCP characteristic curves for different stator materials. Using the model, sensitivity analysis of design parameters (initial pump clearance, stator thickness, material stiffness, number of lobes) on pump performance is carried out. The findings of this study can aid manufacturers and operators in optimizing PCP design and operation.