下扬子区二叠系烃源岩评价与生源环境  

Evaluation and biogenetic derivation and sedimentary environment of source rocks from Permian in the Lower Yangze region

作　　者：赵青芳[1,2] 谢德智 陈建文 梁杰[1,2] 张银国 王建强[1,2] 董贺平 袁勇[1,2] ZHAO Qingfang;XIE Dezhi;CHEN Jianwen;LIANG Jie;ZHANG Yinguo;WANG Jianqiang;DONG Heping;YUAN Yong(Qingdao Institute of Marine Geology,CGS,Qingdao 266071,Shandong,China;Laboratory for Marine Mineral Resources,Laoshan Laboratory,Qingdao 266071,Shandong,China;PetroChina Qinghai Oilfield Company One Oil Production Factory,Haixizhou 816499,Qinghai,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,山东青岛266071 [2]崂山实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266071 [3]青海油田公司采油一厂,青海海西州816499

出　　处：《地质通报》2023年第7期1154-1165,共12页Geological Bulletin of China

基　　金：崂山实验室科技创新项目《中国海域重点盆地发育时空差异及其深部过程》(编号:LSKJ202203401);中国地质调查局项目(编号:DD20190818、DD20211353、DD20221723、DD20230317);国家自然科学基金项目《南黄海崂山隆起中南部海底渗漏烃类源区示踪与运移路径重建》(批准号:41776075);《南黄海崂山隆起二叠系储层油气成藏破坏与流体演化过程还原研究》(批准号:42076220);山东省自然科学基金项目《南黄海盆地崂山隆起石炭系油气保存条件的主控因素分析》(编号:ZR2020MD071)。

摘　　要：基于下扬子区海域-陆域钻井岩心和露头岩样,通过有机岩石学和有机地球化学方法,应用有效指标参数,从不同维度综合分析下扬子区上二叠统大隆组、龙潭组和下二叠统孤峰组、栖霞组4套烃源岩在纵向及平面上的有机地球化学特征、生烃潜力和生源环境。根据测试数据及前人研究资料,栖霞组和大隆组烃源岩的有机质丰度为中等—好级别,龙潭组烃源岩的有机质丰度为一般—中等级别,孤峰组烃源岩有机质丰度达到很好级别。下二叠统烃源岩有机质丰度在平面展布上表现出海域优于陆域的特点,上二叠统则反之。根据干酪根碳同位素特征,栖霞组烃源岩有机质类型最好,为Ⅰ~Ⅱ型;其他3套烃源岩均为Ⅱ~Ⅲ型母质类型。4套烃源岩成熟度参数镜质体反射率主频分布范围为1.3%~2.0%,均达到高热演化阶段,在平面展布上表现出明显的非均一性。二叠系4套烃源岩生物来源以低等水生生物为主,有机质均在贫氧的弱还原—弱氧化条件下保存,其中大隆组沉积的水体动荡频繁和生物变化较明显。综合认为,下扬子区二叠系烃源岩有机质丰度高,类型较好,具有形成大型油气田的良好物质基础,尤其是以往被忽略的孤峰组烃源岩评价等级被提高,是一套潜在的优质烃源岩,其对该区进一步的油气勘探具有重要的指导意义。Based on drilling cores and outcrop samples of the land and ocean area in lower Yangtze region as the research object,by using the research methods of organic petrology and organic geochemistry,reveal the vertical and planar organic geochemical characteristics,hydrocarbon potential,biogenetic derivation and sedimentary environment of four groups of Permian source rocks in the Lower Yangtze region,i.e.the Upper Permian Dalong Formation and Longtan Formation,Lower Permian Qixia Formation and Gufeng Formation.According to the results of the experiment test,combining previous research data,comprehensive analysis shows that the organic matter abundance of the source rocks of Qixia Formation and Dalong Formation are medium-good level,the source rocks of Longtan Formation belong to fair-medium level,the source rocks of Gufeng Formation achieve very good level.Judging from the organic matter abundance,the Lower Permian source rocks which in the Lower Yangtze ocean area are better than in the land area of which,while the Upper Permian source rocks are opposite feature.According to the characteristics of the carbon isotopes,the source rocks of Lower Permian Qixia Formation mainly constitute TypeⅠ-Ⅱkerogen and the other three groups of source rocks are TypeⅡ-Ⅲkerogen.Four groups of Permian source rocks have vitrinite reflectance values ranging mostly from 1.3%to 2.0%,suggesting a high-mature level with regard to hydrocarbon-generating.The results show obvious inhomogeneity in the spatial distribution of mature.Four groups of Permian source rocks have slimilar sterane and terpane characteristics,which biological sources mainly came from low aquatic organisms.Four groups of source rocks were setting in the weak reduction environment to weak oxidation environment,of which depositional environment is turbulent and biological change is obvious in the Dalong Formation.In summary,the Permian source rocks have high organic abundance and good types of organic matter,and provide the material basement for forming large oil and

关 键 词：下扬子区 二叠系 烃源岩评价 生源环境 

分 类 号：P534.46[天文地球—古生物学与地层学] P618.13[天文地球—地质学]