沉积学报2024，Vol.42Issue(2)：701-722,22.DOI:10.14027/j.issn.1000-0550.2022.096
陆相断陷咸化湖盆细粒沉积地层有机质富集特征及控制因素分析
摘要
Abstract
[Objective]The development of the"sweet spot"in lacustrine fine-grained sedimentary shale reservoirs is closely related to the enrichment of organic matter(OM).However,few studies on the causes of OM enrichment and the establishment of enrichment models of shale in faulted saline lacustrine basins have been reported.A typical continental rifted saline lake basin was developed for the upper sub-segment of the upper 4th member of the Shahejie Formation(Es4scs)in the Dongying Sag.To further understand the OM enrichment in fine-grained sedimentary shale during this period,[Methods]This study used thin slice identification,scanning electron microscopy,X-ray diffrac-tion,sporopollenin identification,biomarker chromatography-mass spectrometry and other techniques.The control-ling factors of organic matter enrichment were explored in detail by using each index,and the organic matter enrich-ment model suitable for each stage of environmental evolution of the study area was established.[Results](1)OM occurs at the microscopic level as strips,infills and dispersions.The OM source was mainly lower aquatic organisms such as algae,with evidence of small amounts of terrestrial higher plant material in the middle and upper strata.(2)The sedimentary environment evolved in three stages:A shallow-water semi-arid low-oxygen environment,a deepwater semi-humid reducing environment,and a sub-deepwater semi-arid low-oxygen environment.(3)OM enrichment was mainly influenced by climate,salinity,redox condition,productivity and deposition rate.Water depth,terrestrial input,volcanism and hydrothermal activity were secondary influences.[Conclusions]A model of OM enrichment in fine-grained sedimentary strata of the continental rifted saline lake basin was established,which may be highly significant for the exploration and development of continental shale oil and gas in China.To summa-rize:high OM enrichment in the studied interval was dominated by very productive conditions,a reducing environment for preservation,suitable salinity and suitable deposition rate.关键词
湖相泥页岩/控制因素/富集模式/沙河街组第四段上亚段/东营凹陷Key words
lacustrine mud shale/controlling factors/enrichment mode/sub-section of the upper 4th member of the Shahejie Formation(Es4scs)/Dongying Sag分类
天文与地球科学引用本文复制引用
于乐丹,彭军,许天宇,韩浩东,杨一茗..陆相断陷咸化湖盆细粒沉积地层有机质富集特征及控制因素分析[J].沉积学报,2024,42(2):701-722,22.基金项目
国家自然科学基金项目(41872166) National Natural Science Foundation of China,No.41872166 （41872166）
