鄂尔多斯盆地志丹地区长7_(3)亚段泥页岩地球化学特征及页岩油地质意义  

Geochemical characteristics and geological significance of Chang 7_(3) sub-member mud shale in Zhidan area,Ordos Basin

作　　者：李继宏[1,2] 侯景涛[3] 杨艳宁 谢先奎 李程善 刘广林[1,2] 李树同[6,7] LI Jihong;HOU Jingtao;YANG Yanning;XIE Xiankui;LI Chengshan;LIU Guanglin;LI Shutong(National Engineering Laboratory for Exploration and Development of Low Permeability Oil&Gas Fields,Xi'an 710018,China;Exploration and Development Research Institute of PetroChina Changqing Oilfield Company,Xi'an 710018,China;No.3 Oil Production Plant,PetroChina Changqing Oilfield Company,Ningxian 750006,China;No.6 Oil Production Plant,PetroChina Changqing Oilfield Company,Xi'an 710018,China;Branch Exploration Department of PetroChina Changqing Oilfield Company,Xi'an 710018,China;Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;Key Laboratory of Petroleum Resources,Gansu Province,Lanzhou 730000,China)

机构地区：[1]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [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三采油厂,宁夏银川750006 [4]中国石油长庆油田分公司第六采油厂,陕西西安710018 [5]中国石油长庆油田分公司勘探事业部,陕西西安710018 [6]中国科学院西北生态环境资源研究院,甘肃兰州730000 [7]甘肃省油气资源研究重点实验室,甘肃兰州730000

出　　处：《天然气地球科学》2021年第12期1839-1848,共10页Natural Gas Geoscience

基　　金：国家科技重大专项“大型油气田及煤层气开发”(编号:2016ZX05050)资助.

摘　　要：基于鄂尔多斯盆地志丹地区长7_(3)亚段泥页岩岩心资料,通过有机碳、岩石热解、生物标志化合物、微量元素、有机质族组分等实验测试分析,运用多种有机地球化学参数,综合判识了研究区长7_(3)亚段泥页岩形成环境、母质类型、成熟度以及含油性。研究表明,志丹地区长7_(3)亚段泥页岩沉积环境为弱氧化-还原环境,母质具有水生生物和高等植物的混源特征;长7_(3)亚段泥页岩的TOC平均值为4.65%,生烃潜量(S_(1)+S_(2))平均值为20.86 mg/g,热解T_(max)平均值为447℃,泥页岩的成熟度较高;长7段泥页岩氯仿沥青“A”族组成中烃类组分含量高(平均为52%)、沥青质含量低(平均为3.48%)、饱/芳平均值大(为4.2);长7_(3)亚段泥页岩样品中饱和烃碳数分布在nC_(13)—nC_(33)之间,主峰碳以nC_(15)、nC_(16)为主,偏向低分子量烷烃,ΣC_(21-)/ΣC_(22+)平均值为1.34,体现出烷烃具有短链优势;长7段泥页岩沉积厚度较大、有机质含量高、含油性好,是该地区页岩油潜在的接替目标,未来具有重要的勘探意义。Based on the core data of Chang 7_(3)sub-member mud shale in Zhidan area,through the experimental test and analysis of organic carbon,rock pyrolysis,biomarker compounds,trace elements and organic matter group components,and using a variety of organic geochemical parameters,the formation environment,parent material type,maturity and oil content of Chang 7_(3)sub-member mud shale in the study area were comprehensively identified.The results show that it is a weak oxidation-reduction sedimentary environment,and the parent material has the mixed source characteristics of aquatic organisms and higher plants in Chang 7_(3)sub-member mud shale of the study area.Its TOC is avg.4.65%,hydrocarbon generation potential(S_(1)+S_(2))is avg.20.86 mg/g,pyrolysis T_(max) is avg.447℃,and the maturity is high.The hydrocarbon component content is high(avg.52%),the asphaltene content is low(avg.3.48%),and the average saturated/aromatic hydrocarbon ratio is large(avg.4.2)in the asphalt"A"composition of Chang 7 Member.The carbon number of saturated hydrocarbons is distributed between nC_(13)-nC_(33),and the main peak carbon is mainly nC_(15) and nC_(16) of Chang 7_(3)submember mud shale in the study area,which is biased towards low molecular weight alkanes.ΣC_(21-)/ΣC_(22+)average ratio is 1.34,which reflects the short chain advantage of alkanes.It has large sedimentary thickness,high organic matter content and good oil content of Chang 7_(3)sub-member mud shale in the study area.It is a potential exploration target of shale oil in this area,which has important significance of shale oil.

关 键 词：泥页岩 长7_(3)亚段 地球化学 沉积环境 页岩油 

分 类 号：TE122.113[石油与天然气工程—油气勘探]