油气水三相相对渗透率物理模拟实验

PHYSICAL SIMULATION EXPERIMENT OF OIL-GAS-WATER THREE-PHASE RELATIVE PERMEABILITIES

在油藏注气开发中常伴随油、气、水三相渗流现象,为深入研究油、气、水三相在多孔介质中的渗流特征,需对三相相对渗透率曲线进行测定。采用稳态模拟方法,通过引入阿尔奇公式,建立基于电阻率原理和在线CT扫描相结合的实验方法,分别对不同润湿性岩心中气驱转水驱的IDD饱和历程和水驱转气驱的DDI饱和历程下的油、气、水三相相对渗透率进行测定。结果表明:在水湿岩心中,除水相渗透率是自身含水饱和度的函数外,其他两相渗透率还受除自身饱和度外其他两相饱和度的影响;在油湿岩心中,油、气、水三相的等渗线都是凸向100%自身饱和度顶点的曲线,饱和历程的差异对油、气、水三相等渗线有不同程度的影响。

The phenomenon of oil-gas-water three-phase flow often exists in the development of the gas-injected oil reservoir. In order to further study the three-phase flow characteristics in the porous media,the three-phase relative permeabilities are needed to be measured. With the help of the steady simulating method and the introduced Archie formula,the experimental method was established on the basis of the integration between the resistivity principle and the online CT scanning,the three-phase relative permeabilities were measured in the DDI（ Swdecrease,Sodecrease,Sgincrease） saturation processes from the gas flooding to the water flooding and from the water flooding to the gas flooding for the cores with different wettabilities. The results show that for the water-wet cores,the water permeability is the function of its own water saturation,the other two-phase permeabilities are affected both by their own saturations and the other two-phase saturations; for the oil wet cores,the isotonic lines of the three phases areconvex to 100% of their own saturation axis/top curves,the differences in the saturation processes possess different influences on the three-phase isotonic lines.