A Numerical Simulation Study On Lift Performance Of Progressive Cavity Pump

Progressive cavity pump (PCP) is a kind of device extensively used in the oilfield production. The PCP always runs under high temperature and complex media environment, which induces thermal expansion and swelling of rubber stator. The stator's inner outline is changed by thermal expansion and swelling. The changed inner outline has great impact on the PCP's stress distribution and hydraulic performance.We analyzed the stator's mechanical property under thermal expansion and swelling by three-dimensional nonlinear finite element method. The nonuniform temperature field is studied by one-way decoupling method. The long axis's linear expansion ratio is studied with numerical analysis and experiment. We studied how the inner outline changes under the condition of thermal expansion and swelling using the finite element model. The improved new inner outline is provided at the background of the conventional PCP. The laden torque of the improved PCP is computed, and the results show that the new PCP has better working performance because the new PCP's has induced laden torque and fluctuation. The fluid and structure interaction between stator and rotor is simulated. We compute the pressure on rotor, the deformation of stator and the leakage of PCP. The comparison between simulation results and experimental results shows that the coupled model can simulate the deformation of stator and the PCP's leakage, but the uncoupled model will underestimate the PCP's leakage.We studied PCP's lift performance on temperature field, torque output and volumetric efficiency, and analyzed how some parameters affect the lift performance. The developed coupled model plays a key role on explaining the PCP's hydraulic characteristic. The presented conclusions will play an important role for further research of the PCP and provide guide to the practical design of the new PCP.