岩石润湿性对油气水三相相对渗透率的影响

EFFECT OF WETTABILITY ON THREE-PHASERELATIVE PERMEABILITIES OF WATER/OIL/GAS

在地层温度下.用隐定法对饱和过程为S_w↓S_o↓S_z↓的油湿和水湿人造砂岩的油气水三相相对渗透率进行了实验测定,实验中分别采用电阻率和称重法测水相和油帽的饱和度,用“三段岩心”法消除末端效应。实验结果表明:岩石润湿性对相对渗透率有明显的影响,水湿岩石中,水的等渗线为一组直线。即水相相对渗透率只与水饱和度S_w有关,而与油,气的单独饱和度无关,油、气的相对渗透率与所有三相的饱和度有关,油的等渗线为一组凹向100％S_o点的曲线,气的等渗线为一组凸向100％S_z点的曲线;在油湿岩石中,油,气、水三相的相对渗透率与所有三相的饱和度有关,各相等渗线均为一组凸向100％各自饱和度点的曲线。

An experimental investigation of three-phase water/oil/gas relative permeabilities to saturating history of Sw,↑ S. ↓Sg, ↓ (IDD) in Water-wet and Oil-wet manmade sandstones has been made by using steady-state method in this study. Resistivity and weighting methods have been employed to measure three-phase saturations in the cores. The experimental results show there is a significant effect of wettability on relative permeabilities of water/oil/ gas. In the water-wet stones, three-phase relative permeability to water sandstones depends only on water saturation. Oil isoperms are concave towards 100% oil saturation point, gas isoperms are convex towards 100% gas saturation point, that is, three-phase relative permeabilities to oil and gas depend on all the three-phase saturations; In the oil-wet sandstones, three-phase relative permeabilities to water/oil/gas depend on all the three phase saturations, all the three phase isoperms are convex towards 100% saturation points.