中上扬子地区北缘二叠系孤峰组页岩气地质条件及勘探有利区优选OA
Geological conditions and favorable exploration zones of the Permian Gufeng Formation shale gas in the northern margin of the Middle-Upper Yangtze Region
中上扬子地区北缘二叠系孤峰组是页岩气勘探的新区新层系,但其成藏规律、富集主控因素及勘探潜力缺乏系统研究.为此,基于岩石学、地球化学、储层物性、含气性及区域地质等资料,系统分析了该区孤峰组页岩气的地质条件与勘探前景.研究结果表明:①孤峰组下段(硅质页岩段)为页岩气富集的主要层段,岩性以黑色硅质页岩、碳质页岩为主,有机质丰度极高(平均 TOC＞11%),有机质类型以Ⅱ1 型为主,热演化程度适中(Ro 为 2.0%～2.6%),处于过成熟生干气阶段;②储集空间以有机质孔为主,基质孔隙度平均达 8.48%,孔隙结构以微孔和介孔为主体;③页岩含气性较好(EJY2 井含气量平均为 4.52 m3/t),含气量与 TOC 和孔隙度均呈正相关关系;④富有机质页岩厚度受古地貌与火山活动影响显著,在空间上呈"两凹一隆"的分布格局,保存条件则受顶底板封盖能力、构造抬升剥蚀及断裂发育程度控制.结论认为,中上扬子北缘孤峰组下段具备优越的页岩气成藏地质条件,资源勘探潜力大,研究明确的有利靶区可为该区新层系页岩气勘探部署、产能接替提供重要理论依据与实践支撑.
The Permian Gufeng Formation in the northern margin of the Middle-Upper Yangtze Region is a new area and formation for shale gas exploration,but its hydrocarbon accumulation patterns,enrichment controlling factors and exploration potential lack systematic research.Based on petrology,geochemistry,reservoir physical properties,gas-bearing properties and regional geological data,this paper systematically analyzes the geological conditions and exploration prospects of the Gufeng Formation shale gas in the northern margin of the Middle-Upper Yangtze Region.The following results are obtained.First,the Lower Member of the Gufeng Formation(siliceous shale segment)is the main shale gas enrichment interval,which is lithologically dominated by dark siliceous and carbonaceous shale with extremely high organic matter abundance(average TOC>11%).The organic matter is mainly of Type Ⅱ1,with moderate thermal maturity(Ro of 2.0%-2.6%),indicating an over-maturity stage for dry gas generation.Second,the reservoir space is dominated by organic pores,with an average matrix porosity of 8.48%,and the pore structure is mainly composed of micropores and mesopores.Third,the shale exhibits good gas-bearing properties(the average gas content of Well EJY2 is 4.52 m3/t),and the gas content is positively correlated with both TOC and porosity.Fourth,the thickness of organic-rich shale is significantly affected by paleogeomorphology and volcanic activities,resulting in a spatial distribution pattern of"two depressions and one uplift".The preservation conditions are controlled by the sealing capacity of roof and floor,the structural uplift and denudation,and the degree of fault development.In conclusion,the Lower Member of Gufeng Formation in the northern margin of Middle-Upper Yangtze Region exhibits superior geological conditions for shale gas accumulation and holds immense resource exploration potential.The favorable targets determined in this study can provide an important theoretical basis and practical support for the exploration deployment and production capacity replacement of shale gas in the new formations in the northern margin of the Middle-Upper Yangtze Region.
李世臻;王昱荦;杨晓光;宋腾;徐秋晨;李飞;卢妍欣;沈斌;张小涛;邱振
多资源协同陆相页岩油绿色开采全国重点实验室||中国地质调查局油气资源调查中心||中国地质调查局非常规油气地质重点实验室中国地质调查局油气资源调查中心||中国地质调查局非常规油气地质重点实验室中国地质调查局非常规油气地质重点实验室||中国石化石油勘探开发研究院中国地质调查局油气资源调查中心||中国地质调查局非常规油气地质重点实验室多资源协同陆相页岩油绿色开采全国重点实验室||中国地质调查局油气资源调查中心||中国地质调查局非常规油气地质重点实验室中国地质调查局油气资源调查中心||中国地质调查局非常规油气地质重点实验室中国地质调查局油气资源调查中心||中国地质调查局非常规油气地质重点实验室国家地质实验测试中心国家地质实验测试中心中国石油勘探开发研究院
能源科技
中上扬子地区北缘四川盆地孤峰组页岩气地质条件勘探潜力有利区优选
Northern margin of the Middle-Upper Yangtze RegionSichuan BasinGufeng FmShale gasGeological conditionsExploration potentialOptimization of favorable exploration targets
《天然气工业》 2026 (7)
77-91,15
国家自然科学基金项目"鄂西海槽中上二叠统页岩沉积环境演变与富有机质页岩形成机制"(编号:42472210),中国地质调查局项目"全国页岩气重点调查区战略性矿产调查评价"(编号:DD20230043)、"滇黔桂地区页岩气地质调查与评价"(编号:DD20240048).
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