宣广盆地中二叠世栖霞组层序地层特征及页岩气勘探前景  

Sequence stratigraphic characteristics and shale gas exploration prospect of Middle Permian Qixia Formation in the Xuancheng-Guangde Basin

作　　者：彭晓东 徐锦龙[1] 方朝刚[2] 沈仕豪 章诚诚 PENG Xiaodong;XU Jinlong;FANG Chaogang;SHEN Shihao;ZHANG Chengcheng(Geological Survey of Anhui Province, Hefei 230001, Anhui, China;Nanjing Center, China Geological Survey, Nanjing 210016, Jiangsu, China)

机构地区：[1]安徽省地质调查院,安徽合肥230001 [2]中国地质调查局南京地质调查中心,江苏南京210016

出　　处：《华东地质》2022年第2期154-166,共13页East China Geology

基　　金：中国地质调查局“长江中下游成矿带安庆-盱眙地区地质矿产调查(编号:1212011120848)”、“苏皖地区页岩气地质调查(编号:DD20190083)”;安徽省矿山生态修复工程实验室开放课题(编号:KS-2021-002)项目联合资助

摘　　要：对宣广盆地中二叠世栖霞组进行层序地层学分析,结合栖霞组富有机质页(泥)岩有机地球化学特征,评价页岩气勘探前景。研究表明:区内栖霞组可分为3个三级层序;每个层序划分出海侵体系域、凝缩段和高水位体系域,代表了一次相对较大的海平面升降旋回。富有机质页(泥)岩主要分布于凝缩段、凝缩段与海侵体系域或高水位体系域的转换过渡层段。栖霞组富有机质页(泥)岩厚8~35 m,TOC值0.77%~9.49%,有机质成熟度为1.428%,脆性矿物(石英、长石)相对富集,具有良好的脆性和可压性,页岩气成藏条件良好,特别是栖霞组五段具有巨大的资源潜力。Based on the method of sequence stratigraphy,the stratigraphic sequence of the Middle Permian Qixia Formation in the Xuancheng-Guangde Basin was analyzed.Combined with the organic geochemical characteristics of the organic-rich shale,the shale gas exploration prospect was evaluated.The results show that the Qixia Formation in the Xuancheng-Guangde Basin can be divided into three third-order sequences,which represent three relatively large cycles of sea-level rise and fall.Each sequence can be subdivided into the transgressive systems tract,the condensed section,and the highstand systems tract.The organic-rich shale mainly occurred in the condensed section and transitional sections between the condensed section and transgressive systems tract or highstand systems tract.The thickness of organic-rich shales in Qixia Formation varies from 8 to 35 m.The TOC value ranges from 0.77%to 9.49%,and the maturity of organic matter is about 1.428%.Brittle minerals(quartz,feldspar)of shales are relatively enriched,showing good brittleness and compressibility.Accordingly,shale gas accumulation conditions of Qixia Formation are good,especially for the top limestone section of Qixia Formation,which has great resource potential.

关 键 词：层序地层 页岩气 栖霞组 安徽省宣广盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]