渝东南地区五峰–龙马溪组层序地层特征及地质意义  

Sequence stratigraphy of Wufeng-Longmaxi Formation in the southeastern Chongqing area and its geological significance

作　　者：梁迈[1] 谭先锋[1,2] 陈现军 王佳 冉天[1] 王萍 谭东萍 薛伟伟[4] 曾春林 LIANG Mai;TAN Xianfeng;CHEN Xianjun;WANG Jia;RAN Tian;WANG Ping;TAN Dongping;XUE Weiwei;ZENG Chunlin(College of Petroleum and Natural Gas Engineering,Chongqing University of Science and Technology,Chongqing 401331,China;The Key Laboratory of Unconventional Petroleum Geology,China Geological Survey,Beijing 100029,China;Zhanjiang Branch of China France Bohai Geoservices Co.,Ltd,Guangzhou 524000,China;School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023,China;Chongqing Institute of Geology and Mineral Resources,Chongqing 400042,China)

机构地区：[1]重庆科技学院石油与天然气工程学院,重庆401331 [2]中国地质调查局非常规油气地质重点实验室,北京100029 [3]中法渤海地质服务有限公司湛江分公司,广东广州524000 [4]南京大学地球科学与工程学院,江苏南京210023 [5]重庆地质矿产研究院,重庆400042

出　　处：《煤田地质与勘探》2018年第6期40-51,共12页Coal Geology & Exploration

基　　金：中国地质调查局非常规油气地质重点实验室开放基金项目(DD20160181-YQ17W06JJ02);国家自然科学基金项目(41202043);重庆科技学院研究生科技创新项目(YKJCX1620134)~~

摘　　要：在野外露头观察与实测的基础上,将钻井、录井及实测资料相结合,运用沉积学与层序地层学相关理论方法,对渝东南地区五峰–龙马溪组沉积特征和层序充填特征进行深入研究,并探索油气地质意义。五峰–龙马溪组页岩野外沉积特征明显,识别度高,厚度60～130m,下部为硅质页岩,向上砂质含量逐渐增加,岩性过渡为泥质粉砂岩。通过测井曲线特征、岩性、沉积构造响应及海平面升降,可将五峰–龙马溪组划分为4个三级层序,海侵体系域和高位体系域对称发育,横向上连续性较好,纵向上特征明显;Sq1海侵体系域在研究区内广泛发育,沉积一套硅质页岩,Sq2上部开始发育高位体系域沉积,对应为泥质粉砂岩沉积,Sq3下部发育海侵体系域泥岩沉积,Sq4以高位体系域为主,发育泥质陆棚相炭质页岩沉积。五峰–龙马溪组在整个层序充填过程中受到构造运动和海平面升降的控制,物源主要来自东南缘雪峰古隆起,早期的火山热事件为页岩中大范围硅化现象提供硅质来源的同时,为该时期浮游生物提供了生存条件,促进了五峰–龙马溪组页岩中有机质的发育,为页岩气富集成藏提供了充足的气源。Based on the measurement and field observation of outcrop,the sedimentary and sequence characteristics of Wufeng-Longmaxi Formation in the southeastern part of Chongqing were studied deeply by combining drilling,well logging and measured data with the theories and methods of sedimentology and sequence stratigraphy,the geological significance for oil and gas was explored.The Wufeng-Longmaxi shale has obvious sedimentary features in the field,high degree of recognition,thickness from 60-130 m,siliceous shale in the lower part,gradually increasing sandy content and lithologic transition to muddy siltstone.Through logging curve characteristics,lithology,sedimentary response and sea level rise and fall,Wufeng-Longmaxi Formation can be divided into four third–order sequences.The transgressive system tract and the high stand system tract are developed symmetrically,with good continuity in the horizontal direction and obvious features in the vertical direction.The Sq1 transgressive system tract developed extensively in the study area,depositing a set of siliceous shale.The upper Sq2 began to develop high-level system tract deposition,corresponding to the deposition of argillaceous siltstone.In the lower part of Sq3,the mudstones of the transgressive system tract were developed,and Sq4 at high level system tract dominated the development of clay shale facies carbonaceous shale deposition.Wufeng-Longmaxi Formation was controlled by tectonic movement and sea level rise and fall during the whole sequence filling.The source of Wufeng-Longmaxi Formation mainly came from Xuefeng paleo–uplift on the southern and eastern fronts.The early volcanic thermal events provided siliceous rocks for a wide range of silicification in shale.At the same time,it provided the living conditions for plankton in this period and promoted the development of organic matter in the shale of Wufeng-Longmaxi Formation,which provided sufficient gas source for enrichment of shale gas.

关 键 词：页岩 页岩气 层序地层 五峰–龙马溪组 渝东南地区 

分 类 号：P618.12[天文地球—矿床学]