Abstract: The microcosmic influence factors for electrical properties of low-resistivity reservoir and their influence law in Shinan and Jinjia oilfields were investigated using the percolation network model.The microcosmic factors,such as porous structure,fluid properties,type and content of shale,were analyzed.The results indicate that the microcosmic influence factors of forming the low-resistivity reservoir in Jiyang Depression mainly include amount of micropores,connectivity of pore and salinity of formation water,as well as type and content of shale.For different oilfields,because of the difference in formation properties,the factors mentioned above have different influence intensity on rock resistivity,and the critical salinity of formation water for forming the low-resistivity reservoir is also different.The critical salinities of formation water in Shinan and Jinjia oilfields are 170 grams per liter and 4 grams per liter,respectively.

Key words: Jiyang Depression, low-resistivity reservoir, formation water, critical salinity, numerical simulation, percolation network model

摘要： 以史南、金家两个油田为例,利用逾渗网络模型研究了低电阻率储层电性微观影响因素及规律.研究中充分考虑了储层孔隙结构、流体性质、粘土含量和类型等微观影响因素.研究结果表明,济阳坳陷低电阻率储层形成的微观因素主要有微孔隙发育状况、孔隙连通性、地层水矿化度以及粘土的含量和类型等.对于不同油田,由于储层物性的差别,上述各因素对电阻率影响的相对强度存在明显的差别,形成低电阻率储层的临界矿化度也不相同.史南油田临界矿化度约为170g/L,金家油田临界矿化度约为4g/L.

关键词: 济阳坳陷, 低电阻率储层, 地层水, 临界矿化度, 数值模拟, 逾渗网络模型