Organization
Geophysical Research Institute, SINOPEC Exploration Company, Chengdu 610041, China
摘要
在岩心精细描述的基础上，综合采用全岩矿物X衍射、有机地化、薄片鉴定、储集物性、元素分析等测试手段，开展了涪陵地区凉高山组富有机质泥岩微相特征研究，并分析其与页岩油气富集的关系。研究表明：涪陵地区凉高山组可划分为6种微相类型，纹层状泥岩微相（MF1）指示安静、淡水、还原环境，有利于有机质的保存和富集；块状泥岩微相（MF2）指示弱还原—还原的浅湖环境，水体较MF1浅；粉砂质泥岩微相（MF3）、泥质粉砂岩、粉砂岩微相（MF4）及细砂岩微相（MF5）表征有一定物源供给的浅水环境，古生产力低下，不利于有机质富集；介壳灰岩微相（MF6）指示受波浪改造作用强的浅湖环境。MF1黏土矿物质量分数高，具有较高的总有机碳质量分数（TOC），是有利于烃类生成的微相，其次为MF2；MF3—MF5石英质量分数高，TOC偏低，不利于烃类生成；MF6沉积水体较浅，不利于有机质的富集，TOC偏低。油气显示层厚度及占比表明，MF1与页岩油气的关系最为密切，孔隙度相对较高，为优质页岩油气储层。
Abstract
Based on the detailed description of the core, the microfacies characteristics of organic-rich mudstone of Lianggaoshan Formation in Fuling area are studied by comprehensively using the test methods of whole rock mineral X-ray diffraction, organic geochemistry, thin section identification, reservoir physical properties and element analysis, and the relationship with shale oil and gas enrichment is analyzed. The analysis shows that Lianggaoshan Formation in Fuling area can be divided into six microfacies. Laminar mudstone microfacies（MF1） indicates quiet, fresh water and reduction environment, which is conducive to the preservation and enrichment of organic matter. Massive mudstone microfacies （MF2） indicates weak reduction to reduction shallow lake environment, and the water body is shallower than MF1. Silty mudstone microfacies（MF3）, argillaceous siltstone, siltstone microfacies（MF4） and fine sandstone microfacies （MF5） indicate the shallow water environment with certain provenance supply, and the paleoproductivity is low, which is not conducive to the enrichment of organic matter. The microfacies of shell limestone（MF6） indicate the shallow lake environment with strong wave transformation. MF1 clay has high content and high TOC value, which is a microfacies conducive to hydrocarbon generation, followed by MF2. Quartz mineral of MF3 to MF5 has high content and low TOC value, which is not conducive to hydrocarbon generation. MF6 sedimentary water body is shallow, which is not conducive to the enrichment of organic matter, and the TOC value is low. The thickness and proportion of oil and gas show that MF1 has the closest relationship with shale oil and gas, and the porosity test is relatively high, so it is a high-quality shale oil and gas reservoir.
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