琼海凸起珠江组一段低电阻率油层的微观成因机理分析

琼海凸起珠江组一段低电阻率油层岩石类型为石英砂岩和长石石英砂岩，以高泥质、低碳酸盐胶结物特征，物性特征为高--中孔、中--低渗。油层表现为低电阻率特征的原因包括: ① 岩性为泥质粉砂岩与细砂岩与粉砂质泥岩互层，粒级较细; ② 黏土矿物以伊蒙混层和伊利石为主，且以贴附颗粒表面生长为主要产状; ③ 以微喉为主的喉道特征。导电矿物含量少，对油层电阻率贡献较小。

Analysis on micro-geological causes of low-resistivity oil layers from Member 1 of Zhujiang Formation in Qionghai uplift

The types of rocks containing low-resistivity oil layers from Member 1 of Zhujiang Formation in Qionghai uplift are quartz sandstone and feldspar-quarz sandstone,characterized by high mud,low carbonate mineral cementation and high-mederate porosity,with mederate-low permeability.The reasons to low-resistivity of oil layer forming include ① lithologic characters are argillaceous siltite and fine sandstone and silt mudstone interbedding,with fine grains of sandstone;② clay minerals are mainly illite /smectite and illite,growing on the surface of grains forming clay coating;③ the teroat facture is mainly micro-throat.Little of electric mineral contribute to low-resistivity of oil layer slightly.