盐系地层低电阻率油层形成机理与识别——以江汉盆地潜江凹陷潜江组为例

ORIGIN AND IDENTIFICATION OF LOW RESISTIVITY OIL FORMATION IN SALT BED

通过储集层粘土矿物类型、骨架颗粒特征、岩石润湿性、特殊重矿物导电特性研究,对潜江凹陷潜江组低电阻油层的成因进行了分析,认为油层岩石骨架粒度分布形式、骨架颗粒平均粒径小、泥岩与粘土矿物产生的高束缚水含量和特殊重矿物的存在是形成低电阻率油层的主要影响因素。根据低电阻率油层特点,建立了图版法、测井曲线重叠法和定量解释法等识别低电阻率油层的方法,并确定了判识标准,在实际应用中取得了良好效果。

Based on the study of clay mineral types, characters of rock frameworks and grains, wettability of the rocks, conductance of special heavy minerals, the origin of low resistivity reservoir of Qiangjiang formation in Qiangjiang sag is identified, rock＇s character of reservoir has a little infection on the formation of low resistivity reservoir; irreducible water content in the rock is the major factor; the odditional conductivity caused by mud and clay and incursion of the mud filtrate are the minor factors. According to the characteristics of low resistivity reservoir, the diagram version method, well-logging curve overlap method and quantitative analysis etc are set up. The methods are taken in practice and got good results.