下扬子皖南宣泾地区二叠系海相页岩特征及其沉积环境  

Characteristics of Permian Marine Shale and Its Sedimentary Environment in Xuanjing Area,South Anhui Province,Lower Yangtze Area

作　　者：白卢恒 石万忠[1,2] 张晓明[1,2] 徐笑丰 刘俞佐 杨洋 冯芊 曹沈厅 Bai Luheng;Shi Wanzhong;Zhang Xiaoming;Xu Xiaofeng;Liu Yuzuo;Yang Yang;Feng Qian;Cao Shenting(School of Earth Resources,China University of Geosciences,Wuhan 430074,China;Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学资源学院,湖北武汉430074 [2]中国地质大学构造与油气资源教育部重点实验室,湖北武汉430074

出　　处：《地球科学》2021年第6期2204-2217,共14页Earth Science

基　　金：政府间国际科技创新合作重点专项(No.2017YFE0106300);国家自然科学基金(No.41672134);“十三五”国家科技重大专项(No.2016ZX05034-002-003)。

摘　　要：为评价下扬子地区二叠系海相页岩层段页岩气勘探潜力,以皖南宣泾地区3口钻井岩心为例,通过岩心照片、薄片、X射线衍射、总有机碳等测试来分析页岩特征及其沉积环境.结果显示宣泾地区孤峰组中上部为富有机质层段,银屏组为贫有机质层段;宣泾东南地区大隆组中下部为高-富有机质层段,西北地区中上部为富有机质层段.孤峰组早期随着构造沉降和海水加深,宣泾地区形成了高生物生产力和缺氧环境,沉积了较厚硅质岩层;中晚期海平面缓慢下降,生物生存空间减少,高有机质沉降使水体硫化,TS含量增大,TOC含量达10%.银屏组沉积期海平面快速下降,变为浅海氧化环境,TOC含量小于1%.大隆组早期东南浅水斜坡位置受上升流影响,形成高生物生产力和缺氧环境,沉积了硅质岩层,TOC含量大于4%;中晚期海平面下降,TOC含量从东南浅水向西北深水变高.In order to evaluate the shale gas exploration potential of Permian marine shale in the Lower Yangtze region,the shale characteristics and sedimentary environment were analyzed by core photos,thin sections,X-ray diffraction and total organic carbon tests from three drilling cores in Xuanjing area of south Anhui Province.It shows that in Xuanjing area the middle-upper parts of Gufeng Formation are rich in organic matter,and Yinping Formation is a poor organic matter interval.The middle and lower parts of Dalong Formation in the southeast of Xuanjing are high-rich organic matter intervals,and the middle and upper parts of northwest are rich organic matter intervals.In the early stage of Gufeng Formation,with the tectonic subsidence and the seawater deepening,Xuanjing area formed a high biological productivity and anoxic environment formed in Xuanjing area,and a thick siliceous rock layer deposited.In the middle and late periods,the sea level decreased slowly,the living space of organisms decreased,and the sedimentation of high organic matter made the water sulfide,and the TS content increased,and the TOC content reached 10%.During the sedimentary period of Yinping Formation,the sea level dropped rapidly and changed into shallow sea oxidation environment with TOC content less than 1%.In the early stage of Dalong Formation,the position of southeast shallow water slope was affected by upwelling,forming a high biological productivity and anoxic environment,and deposited siliceous rock layer with TOC content greater than 4%.In the middle and late period,the sea level dropped,and the TOC content increased from southeast shallow water to northwest deep water.

关 键 词：下扬子 宣泾地区 二叠系 海相页岩 沉积环境 石油地质 

分 类 号：P534.46[天文地球—古生物学与地层学]