Pressure changes in two-phase flow of gas and liquid in a wellbore

Abstract

The phenomenon of high gas-liquid ratio has an impact during the lifting process of oil wells, and it is necessary to study the variation of the two-phase flow of gas and liquid in the wellbore. In this paper, the pressure losses along the wellbore and the coupling pressure losses in the process of gas-liquid two-phase flow in the wellbore were studied through experiments. It was found that with the increase in gas content, the pressure losses gradually decreased, and there was a turning point in the pressure losses within the gas content range of 10-15%. With the increase in flow rate, the pressure losses also increased. The theoretical model was used to calculate the bottom hole pressure values of actual oil wells under different gas contents and flow rates. It was found that in the calculation process, the dominant flow regime is often slug flow. Through experiments and theoretical calculations, the influence of gas content and flow rate on the pressure inside the wellbore was determined, providing guidance for understanding the changes in pressure during the lifting process of oil wells.