基于界面张力影响的凝析气藏相渗时变表征方法

Characterization method of time?鄄varying relative permeability in condensate gas reservoir based on influence of interfacial tension

李元生 伍锐东 邓雅婷 藤赛男

中海石油（中国）有限公司上海分公司研究院，上海 200030 中国石化上海油气分公司勘探开发研究院，上海 200120

Research Institute, Shanghai Branch of CNOOC Ltd., Shanghai 200030, China Research Institute of Exploration and Development, Shanghai Oil and Gas Company, SINOPEC, Shanghai 200120, China

凝析气藏油气界面张力对凝析油的分布及渗流影响显著，但是量化界面张力的影响并反映至数值模拟中的研究较少。文中详细阐述了界面张力对凝析油分布的影响机理，并通过相渗实验定量评价了界面张力对凝析油气相渗及临界流动饱和度的影响，在此基础上回归了基于界面张力影响的变临界流动饱和度公式，建立了变凝析油临界流动饱和度数值模拟机理模型，实现了界面张力对生产影响的模拟。研究表明：界面张力对凝析油气临界流动饱和度影响显著，生产早期低界面张力时，凝析油以油膜形式流动，凝析油临界流动饱和度较低；但随着界面张力的增大，凝析油主要以油塞和油桥的形式存在，凝析油临界流动饱和度迅速增加；数值模拟中，表现为从低界面张力下少量凝析油到较高界面张力下大量凝析油聚集，从而更真实地表征了凝析油在近井地层的聚集特征，提高了凝析气藏数值模拟精度。

he effect of oil?鄄gas interfacial tension (IFT) on the distribution and flow of gas condensate is significant in condensate gas reservoir, but there are few studies on quantifying the interfacial tension and characterizing it in numerical simulation. This paper elaborates on the mechanism of the influence of IFT on the distribution of condensate gas, and quantitatively analyzes the influence of IFT on the relative permeability and critical flow saturation of condensate gas through relative permeability experiments. On this basis, the variable critical flow saturation formula is regressed based on the influence of IFT. Finally, the influence of IFT on production was simulated by establishing a numerical simulation mechanism model of the variable critical flow saturation. The results show that the IFT has a significant impact on the critical flow saturation of condensate gas. When the IFT is low in the early stage of production, the condensate flows in the form of an oil film, and there is a lower critical flow saturation of condensate; but with the increase of the IFT, critical flow saturation of condensate gas increases rapidly, and the condensate exists in the form of liquid plugs and oil bridges; the numerical simulation shows that the critical flow saturation of condensate changes from small under low IFT to large under high IFT, which more accurately characterizes condensate accumulation in the near-wellbore formation, improving accuracy of numerical simulation in condensate gas reservoir.

10.6056/dkyqt202206021