Abstract: A percolation network model for expressing pore structure and fluid characteristics of reservoir was developed.The effects of size and shape of pores,connectivity and the amount of micropores in reservoirs on the relative curve of the resistivity index I with the water saturation S_w were simulated by numerical modeling.The effects of formation water salinity on the rock resistivity were discussed.The relative magnitude of the different influencing factor was analyzed.The quantitative simulation of the different factors affecting the I—S_w curve shows that the connectivity of the void space and the amount of micropores have the greater effect on the I—S_w curve than other factors.The salinity of formation water has a great effect on the absolute resistivity value.The non-archie phenomenon is prevalent and remarkable in reservoir rocks with low permeability.

Key words: reservoir, rock resistivity, resistivity index, formation water salinity, saturation exponent, percolation network model

摘要： 建立了能够反映储层孔隙结构、流体特征的逾渗网络模型,通过数值模拟研究了储层孔隙尺寸、孔隙形状、连通性和微孔隙的发育状况等对电阻率指数I与含水饱和度S_w关系曲线的影响规律,分析了地层水矿化度对岩石电阻率的影响,讨论了不同因素对电阻率影响的相对强度,通过曲线拟合定量地研究了不同因素对I-S_w曲线的影响规律.研究结果表明,在上述影响因素中,连通性和微孔隙对I-S_w曲线的影响很大,其他因素的影响较小;地层水矿化度对岩石电阻率绝对值的影响很大."非阿尔奇"现象普遍存在,在低渗透(低连通性)储层岩石中更为明显.

关键词: 储层, 岩石电性, 电阻率指数, 地层水矿化度, 饱和度指数, 逾渗网络模型