页岩储层孔隙类型控制因素研究——以川东焦石坝地区龙马溪组为例

发布时间：2018-05-07 21:05

本文选题：控制因素 + 分布特征　；参考：《石油实验地质》2017年01期

【摘要】：为了明确页岩不同岩相类型中孔隙类型的构成和垂向分布特征,选取川东龙马溪组7个页岩样品,进行氩离子抛光扫描电镜成像,对其孔隙类型进行定量分析。考虑到页岩的非均质性,每个样品选取5个区域,每个区域由100张放大倍数为14 000倍的SEM照片拼接组成(10μm×10μm),对每张SEM照片进行2000计点法统计各类型孔隙的面孔率,最后归纳得出每个样品中不同类型孔隙的平均百分含量。研究区可观察到3大类孔隙:粒间孔、粒内孔和有机质孔,不同岩相类型中各类型孔隙占比不同,龙马溪组自上而下页岩岩相类型变化趋势为黏土质页岩—粉砂质页岩—硅质页岩,随着黏土矿物含量逐渐减少,有机质含量和石英含量逐渐增加,其主要孔隙类型由粒内孔转变为有机质孔。脆性矿物含量对以粒缘孔为主的粒间孔数量起着控制作用;黏土矿物含量控制以片间孔为主的粒内孔发育程度;有机碳和自生石英含量决定着有机质孔的数量。龙马溪组下段的硅质页岩是页岩气最有利储层。
[Abstract]:In order to determine the pore type composition and vertical distribution of shale in different lithofacies types, seven shale samples from Longmaxi formation in East Sichuan were selected for argon ion polishing scanning electron microscope imaging, and the pore types were quantitatively analyzed. Considering the heterogeneity of shale, five regions are selected for each sample, and each area is composed of 100 SEM photographs with a magnification of 14000 times. The face rate of each type of pore is calculated by 2000 points method for each SEM photo, which is composed of 10 渭 m 脳 10 渭 m. Finally, the average percentage content of different types of pores in each sample is concluded. Three types of pores can be observed in the study area: intergranular pore, intragranular pore and organic pore. The change trend of lithofacies from top to bottom shale in Longmaxi formation is clay shale, silty shale and siliceous shale. With the decrease of clay mineral content, the content of organic matter and quartz increases gradually. The main pore types change from intragranular pore to organic pore. The content of brittle minerals plays a controlling role in the number of intergranular pores dominated by marginal pores; the content of clay minerals controls the development of intragranular pores dominated by interlamellar pores; and the content of organic carbon and authigenic quartz determines the number of organic pores. The siliceous shale in the lower member of Longmaxi formation is the most favorable reservoir for shale gas.
【作者单位】：中国石油大学(北京)地球科学学院;中国石油大庆油田有限责任公司第二采油厂;
【基金】：中国博士后科学基金“富有机质页岩中自生石英成因机制及对页岩气勘探的意义”(2016M591350)资助
【分类号】：P618.13

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