鄂尔多斯盆地东部本溪组一段泥页岩元素地球化学特征——以山西临县招贤剖面和M115井为例  

Element geochemical characteristics of shale in the First Member of Benxi Formation in eastern Ordos Basin:Take Zhaoxian section and Well M115 in Linxian County,Shanxi as examples

作　　者：崔晨光 张辉[2] 刘文香[2] 李仕芳 刘燕[2] 宋换新 吴陈君 文志刚 CUI Chenguang;ZHANG Hui;LIU Wenxiang;LI Shifang;LIU Yan;SONG Huanxin;WU Chenjun;WEN Zhigang(Key Laboratory of Oil and Gas Resources and Exploration Technology of Ministry of Education,College of Resources and Environment,Yangtze University,Wuhan 430100,China;China Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi'an 710018,China;No.10 Oil Production Plant,PetroChina Changqing Oilfield Company,Qingyang 745100,China)

机构地区：[1]长江大学资源与环境学院,油气资源与勘探技术教育部重点实验室,湖北武汉430100 [2]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [3]中国石油长庆油田分公司第十采油厂,甘肃庆阳745100

出　　处：《天然气地球科学》2022年第6期1001-1012,共12页Natural Gas Geoscience

基　　金：中国石油长庆油田分公司科研项目“鄂尔多斯盆地中东部本溪组泥页岩地质特征及有利目标评价”(编号:技2020-151)资助。

摘　　要：石炭系本溪组页岩是鄂尔多斯盆地中东部上古生界页岩气勘探的重要目标层段。在对其代表性野外剖面、钻井岩心系统观测及采样分析的基础上,利用主量、微量元素分析资料,结合全岩矿物组成、有机碳含量、有机显微组分等测试资料,对鄂尔多斯盆地东部本溪组一段(本1段)海陆过渡相泥页岩沉积期古气候、水体环境及与其富有机质泥页岩发育关系进行研究。结果表明:研究区本1段泥页岩主要为黏土质页岩和硅质页岩,矿物组成中石英和黏土矿物占绝对优势;CIA、Sr/Cu、C值参数表明本1段沉积期主要表现为炎热潮湿古气候特征;Sr含量、Sr/Ba、Ba/Ga等参数指示本1段上亚段和下亚段沉积水体盐度分别为咸水、咸水—半咸水,表明该段沉积晚期水体盐度相对较高;V/(V+Ni)、Ce_(anom)、Th/U等参数表明本1段沉积期水体以缺氧—贫氧环境为主。炎热潮湿的古气候、偏咸化和缺氧—贫氧的沉积水体环境等较好的有机质保存条件,是本1段,特别是其上亚段富有机质泥页岩发育的有利因素。优质页岩发育为研究区页岩气勘探提供了良好的基础。The Carboniferous Benxi Formation shale is an important target interval for shale gas exploration in the Upper Paleozoic in the central and eastern Ordos Basin.On the basis of its representative field profile,drilling core system observation and sampling analysis,using the analyticaldata of major and trace elements,combined with the test data of the whole rock mineral composition,organic carbon content,organic microscopic composition,and so on,the palaeoclimate,water environment and the relationship with the development of organic-rich mud shale during the sedimentary period of the First Member of Benxi Formation in the eastern Ordos Basin are studied.The results show that the shale in the First Member of Benxi Formation of the study area is mainly clayey shale and siliceous shale,and quartz and clay minerals are absolutely dominant in the mineral composition;the CIA,Sr/Cu,and C value parameters indicate that the sedimentary period of the first member is mainly hot characteristics of wet paleoclimate;Sr content,Sr/Ba,Ba/Ga and other parameters indicate that the salinity of the sedimentary water in the upper and lower sub-members of the member is saline water,saline water-brass water,respectively,indicating that the water body salt in the late depositional period of this member was at relatively high degree;V/(V+Ni),Ce_(anom),Th/U and other parameters indicate that the water body in this sedimentary period was dominated by anoxic-poor oxygen environment.The hot and humid paleo-climate,the saline anoxic-poor sedimentary water environment and other good organic matter preservation conditions are favorable factors for the development of organic-rich shale in this section,especially the upper subsection.The development of high-quality shale provides a good foundation for shale gas exploration in the study area.

关 键 词：元素地球化学 富有机质页岩 本溪组 沉积环境 古气候 鄂尔多斯盆地 

分 类 号：TE122.113[石油与天然气工程—油气勘探]