Leakage flow correlation of a progressive cavity pump delivering shear thinning non-Newtonian fluids

Abstract

The majority of the complex fluids in petroleum engineering applications are shear thinning non-Newtonian. The industry pumps non-Newtonian fluids by progressive cavity pumps (PCPs) are being used for pumping non-Newtonian fluids in the petroleum industry from the past few years. In this work, an experimental setup was developed and the objective is to study the performance of a PCP delivering shear thinning non-Newtonian fluids and the effect of speed, slurry viscosity and differential pressure on the leakage and volumetric efficiency of the pump. The fluids were prepared by mixing bentonite, water and 0.06% of Na2CO3 to maintain pH level at 8.5-9.5, and the mixture produced are shear thinning non-Newtonian fluid. It was observed that the pump efficiency increases with the increase in viscosity, which reduces the pump leakage. At a higher speed, the pump leakage was lower and volumetric efficiency was higher while increased differential pressure caused an increase in leakage and a decrease in volumetric efficiency. Using the experimental results, a polynomial regression model was developed to predict the leakage of the pump. The correlation development approach can be implemented in the other type of pumps and can cut down experimental expenses. [Received: May 24, 2015; Accepted: January 9, 2016]