水平气井全井段气水两相流动数值模拟分析

Numerical simulation analysis of gas-water two-phase flow in full-hole of horizontal gas well

水平井钻采技术井筒形态复杂,导致井筒管流产生相应的变化,影响地面井控装置操作参数的确定。为明确水平井气水两相流动规律,建立水平井积液识别方法,利用相似原理建立水平气井全井段气水两相流动理论计算模型,应用多相流模拟软件对水平井积液过程进行数值模拟分析。模拟结果表明,水平井积液后水平段的压力损失较小,积液易堆积在造斜段,对产能造成较大影响。各井段持液率的影响因素分析结果显示,当管径大于40 mm时,持液率大幅增加;当上倾角为65°时,持液率出现峰值,且倾角与持液率呈角度函数变化趋势。该研究对建立水平井积液识别方法提供理论支撑。

The shape of wellbore with horizontal well drilling and production technology is complex,which leads to corresponding changes in wellbore pipe-flow and then affects the determination of the operating parameters of surface well control device.In order to clarify the pattern of gas-water two-phase flow in horizontal wells and establish a method for identifying liquid load in horizontal wells,a theoretical calculation model of gas-water two-phase flow in full-hole of horizontal gas well was established according to the similarity principle,and the process of liquid loading in horizontal well was numerically simulated using the multi-phase flow simulation software.The results show that the pressure loss in the horizontal section after liquid loading is small,and the liquid easily accumulates in the deflection section,which has a great impact on the productivity.According to the analysis of factors influencing the liquid holdup in each well section,when the pipe diameter is greater than 40 mm,the liquid holdup increases significantly;when the up-dip angle is 65°,the liquid holdup reaches a peak,and the dip angle and the liquid holdup tend to change as an angle function.This study provides a theoretical support for establishing a method for identifying liquid load in horizontal wells.