利用水膜厚度确定低渗透砂岩储层孔隙度下限

针对现今低渗透砂岩储层孔隙度下限确定的不准确性,本文从孔隙结构和常规物性两个方面来研究,并通过水膜厚度最终确定低渗透砂岩储层孔隙度下限。孔隙结构参数是描述岩石孔隙结构特征的定量指标,以此来研究低渗透砂岩储层的孔隙结构特征。在低渗透砂岩储层中,孔隙吼道参数与水膜厚度在同一数量级上,利用水膜厚度,结合压汞资料,做出孔隙度和大于0.195μm孔喉体积百分数图版,确定低渗透砂岩储层孔隙度下限。

The research on the determination of the porosity limitation of the low permeability sandstone reservoirs by the water film thickness

Based on the data obtained in mercury injection experiment and the researching of physical property and pore structure, the high mean value of the study area shows that the throat is mostly micro ones; slight standard deviation presents a well-sorted reservoir and generally tiny throat, the coefficient of variation is low, which indicates a poor pore structure. low permeability, high capillary pressure and high irreducible water saturation are characters of a typically low permeability sandstone reservoir. Pore-throat parameters and the water film thickness are of the same magnitude in low permeability sandstone reservoirs. Combining the mercury injection data and the water film thickness, the paper completes a probability distribution chart of porosity and pore throat width larger than 0.195 μm, and then it determines the porosity limit of the low permeability sandstone reservoir of the study area is 3.5 %.