摘要
近两年我国南方川北-鄂西地区上二叠统吴家坪组-大隆组取得了页岩气重大勘探突破,并在中二叠统孤峰组发现了勘探新苗头,但其富有机质层段的分布规律及其页岩气资源潜力仍不清楚.通过对川北-鄂西地区中二叠统地层开展沉积相识别与层序地层对比划分,分析不同层序的岩相古地理演化特征,进而探讨该区孤峰组富有机质层段的分布规律与页岩气资源潜力.研究结果表明:川北-鄂西地区中二叠统可划分为3个三级层序SQ1、SQ2和SQ3,其中层序SQ3对应于孤峰组,沉积于卡匹敦晚期;层序SQ3沉积时期,该区在碳酸盐岩台地(对应层序SQ1和SQ2)基础上发育了3个北西向展布的深水盆地,即鄂西盆地、开江-梁平台盆(海槽)和广旺台盆(海槽);孤峰组硅质岩与硅质页岩层段的有机碳TOC含量较高(平均TOC含量为3%~10%),且展布相对连续稳定;峨眉山地幔柱事件驱动了该区中二叠世晚期深水斜坡-盆地环境的形成,从而控制着孤峰组富有机质硅质岩与硅质页岩的大规模区域性沉积.基于上述分析,综合硅质岩及硅质页岩有效厚度、TOC含量、构造保存条件等页岩气地质评价要素,在川东北至湘鄂西地区优选出5个有利区,面积约为1.2×10^(4)km^(2),估算总资源量约1.75×10^(12)m^(3),展示了良好的页岩气勘探开发潜力.
In the last two years,significant breakthroughs have been achieved in the shale gas exploration within the Upper Permian Wuchiaping Formation to Talung Formation in the northern Sichuan and western Hubei provicnes,South China.Furthermore,a promising exploration perspective has also emerged in the Middle Permian Kuhfeng Formation.However,the distribution patterns of the organic-rich strata and the potential shale gas resources in these formations are not yet fully understood.By identifying sedimentary facies and correlating sequence stratigraphy in the Middle Permian of northern Sichuan and western Hubei area,the characteristics of lithofacies paleogeography in different sequences and their evolution were analyzed.Following this,it explores the distribution patterns of organic-rich layers and the shale gas resource potential in the Kuhfeng Formation.The research reveals that three third-order sequences,namely SQ1,SQ2,and SQ3,are identified from the Middle Permian formations in the northern Sichuan and western Hubei area.Specifically,sequence SQ3 corresponds to the Kuhfeng Formation and was deposited during the late Capitanian.During the deposition of sequence SQ3,three northwest-trending deep-water basins developed on a carbonate platform(corresponding to sequences SQ1 and SQ2).These basins are the western Hubei Basin,the Kaijiang-Liangping Platform Basin(trough),and the Guang-Wang Platform Basin(trough),respectively.The Kuhfeng Formation exhibits a relatively continuous and stable distribution of organic-rich layers,mainly including bedded chert and siliceous shale layers with high organic carbon content(average TOC content ranging from 3.0% to 10%).The Emeishan mantle plume contributed to the formation of the deep-water slope-basin environment during the late Middle Permian in this area,further controlling the large-scale regional deposition of organic-rich bedded cherts and siliceous shales within the Kuhfeng Formation.Based on these above results and further comprehensive analyses of geological evaluation fact
作者
邱振
窦立荣
吴建发
韦恒叶
刘雯
孔维亮
张琴
蔡光银
张淦
吴伟
李世臻
曲天泉
高万里
Qiu Zhen;Dou Lirong;Wu Jianfa;Wei Hengye;Liu Wen;Kong Weiliang;Zhang Qin;Cai Guangyin;Zhang Gan;Wu Wei;Li Shizhen;Qu Tianquan;Gao Wanli(PetroChina Research Institute of Petroleum Exploration and Development,Beijing 10083,China;National Energy Shale Gas R&D(Experiment)Center,Beijing 10083,China;Shale Gas Research Institute of PetroChina Southwest Oil&Gas Field Company,Chengdu 610051,China;School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China;Oil and Gas Survey,China Geological Survey,Beijing 100083,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2024年第2期712-748,共37页
Earth Science
基金
国家自然科学基金项目(Nos.42222209,42272118,92255302和42102198)
中国石油天然气集团公司项目(Nos.2023ZZ0801,2021yjcq02和2021DJ2001)
四川省自然科学基金项目(No.2023NSFSC0279)。
关键词
页岩气
三级层序
沉积相
孤峰组
四川盆地
鄂西盆地
非常规油气沉积学
石油地质
shale gas
third-order sequence
facies
Kuhfeng Formation
Sichuan Basin
Western Hubei Basin
unconventional petroleum sedimentology
petroleum geology
