川南地区龙潭组页岩气成藏条件及有利区分析

摘要

基于钻井、岩心样品等分析资料，对川南地区上二叠统龙潭组页岩气成藏条件进行了系统分析，认为该区上二叠统龙潭组页岩主要形成于海陆过渡沉积相，页岩厚度较大（20~120m），富含有机质，有机质丰度高（TOC为0.85%~35.7%，平均7.51%），有机质类型主要为Ⅲ型，热演化程度达高一过成熟（Ro为1.95%~2.4%，平均2.22%），利于干气生成；页岩富含脆性矿物和黏土，微米级孔隙比较发育，利于吸附气赋存。与成功勘探开发页岩气的北美页岩相比，川南地区龙潭组页岩有利于干气的生成及赋存，综合分析提出了泸州—自贡—宜宾、女基井—潼南—高科井2个区块为页岩气富集有利区。%Based on analytic data of drilling core samples, systematically analyzed upper Permian Longtan Formation shale gas reservo⁃iring conditions in southern Sichuan area. The analysis considered that the shale in the area was formed in marine continental transition sedimentary facies with thicker shale (20~120m), rich organic matter, high organic matter abundance (TOC 0.85%~35.7%, average 7.51%), organic mater type III, high to over matured thermal evolution degree (Ro 1.95%~2.40%, average 2.22%), thus favorable to dry gas generation. The shale is rich in brittle minerals and clay, rather well developed micro grade fissures, favorable to adsorptive gas hosting. Comparing with successfully explored and exploited North American shale, the shale in this area is favorable to dry gas genera⁃tion and hosting, the comprehensive analysis has put forward two sectors of Luzhou—Zigong—Yibin and Nujijing—Tongnan—Gaoke⁃jing as shale gas enrichment favorable areas.