Research on the Influence of Various Factors Inside the Wellbore on Liquid Holdup and Gas–Liquid Ratio

Abstract

The changes in liquid holdup and gas–liquid ratio during wellbore oil and gas extraction have a significant impact on the development of oil and gas fields. To comprehensively explore the influence of various factors on liquid holdup and gas–liquid ratio, this study is based on a transient flow mathematical model and a unified two-phase flow pattern. Horizontal and vertical wellbore models are established using multiphase flow transient simulation software OLGA, based on phase equilibrium and mechanical analysis. The focus was on analyzing the effects of factors such as inlet temperature, inlet pressure, flow rate, wellbore diameter, and inclination angle on wellbore holdup and gas–liquid ratio. The reasons for flow pattern changes and the physical mechanisms of changes in holdup and gas–liquid ratio at each node were discussed in detail. Using the random forest method, the variation data of gas–liquid ratio and liquid holdup under different factors were analyzed to quantify the degree of influence of each factor on gas–liquid ratio and liquid holdup. The research results can be used to determine the optimal construction parameters in practical engineering and provide key guidance for oil and gas field production design and resource utilization maximization.