Effect of clearance volume on the internal flow characteristics and output performance of oil-gas multiphase reciprocating pump

Abstract

In the production of oil and natural gas, excessive clearance volume is an important factor affecting the normal operation of oil-gas multiphase pump. Currently, little research has been conducted on the effect of clearance volume on the output characteristics of multiphase pump at home and abroad, leading to extremely low efficiency in the field application of multiphase pump. Therefore, this study conducted numerical calculations on the internal flow characteristics and output performance of multiphase pump under different clearance volumes using FLUENT software. Results show that pressure and fluid velocity gradually decrease as the clearance volume increases. Simultaneously, the number and intensity of vortex flow gradually increase, media pressurization speed becomes slower, and the lag angle of the discharge valve opening becomes larger. Moreover, under conditions with a higher gas volume fraction, multiphase pump with larger clearance volumes experiences gas locking. Furthermore, this study provides a theoretical basis for the reasonable design of clearance volume for multiphase pump by drawing a relationship curve between gas volume fraction and clearance volume. These research findings can provide theoretical support for the performance optimization and design improvement of multiphase pumps.