Optimal stator adjustment with minimal sensor requirements for variable stator progressing cavity pumps

Abstract

The classical progressing cavity pump design features constant rotor and stator geometries. Pump efficiency decreases over time due to mechanical wear of the pump components. Variable stator progressing cavity pumps can compensate for mechanical wear up to a certain extent with manual adjustments of the stator geometry. Thus, progressing cavity pump designs with variable stator replace an increasing number of classical pumps. The optimal adjustment of the variable stator is crucial for efficient pump operation. Currently the optimal in-situ stator adjustment requires expensive flow rate measurements and expert knowledge. Consequently many variable stator progressing cavity pumps operate with suboptimal stator configurations. This contribution proposes a novel procedure for adjusting the variable stator of a progressing cavity pump. The procedure only relies on easy-to-acquire process variables and can be implemented on low-cost embedded hardware. A laboratory test setup is used to validate the proposed approach.