坳陷湖盆烃源岩发育样式及其对石油聚集的控制——以鄂尔多斯盆地三叠系延长组长7油层组为例  

Development patterns of source rocks in depression lake basin and its controlling effect on oil accumulation:Case study of the Chang 7 shale of the Triassic Yanchang Formation,Ordos Basin

作　　者：崔景伟[1,2] 朱如凯 李森[1] 齐亚林 时晓章 毛治国[1,2] Cui Jing-wei;Zhu Ru-kai;Li Sen;Qi Ya-lin;Shi Xiao-zhang;Mao Zhi-guo(Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083;Key Laboratory of Petroleutn Reservoir,CNPC,Beijing 100083,China;Research Institute of Petroleum Exploration and Development,Changqing Oilfield Com party,CNPC,Xi'an 710018,China;Research Institute,Yanchang Petroleum Group Co.Ltd.,Xi'an 710075,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油油气储层重点实验室,北京100083 [3]中国石油长庆油田公司勘探开发研究院,陕西西安710018 [4]延长石油集团有限责任公司研究院,陕西西安710075

出　　处：《天然气地球科学》2019年第7期982-996,共15页Natural Gas Geoscience

基　　金：国家科技重大专项(编号:ZX201705001-01-004);国家重点基础研究发展计划(973)项目(编号:2014CB239000)联合资助

摘　　要：鄂尔多斯盆地中生界T—J1含油系统,石油富集程度、主力产层和烃源岩分布均具有较强的地区差异性,对该差异性缺少系统研究.对盆地内不同区域8口长取心井长7油层组烃源层开展系统的地球化学分析,结合测井ΔLogR法计算出300口井长7油层组总有机碳丰度与纵向分布,依据工业油流井和低产井划定长8、长7和长6油层组油藏有利分布区.研究发现烃源岩纵向上存在5种分布样式并存在较强的区域性差异:湖盆西北部姬塬地区以底部富集型和全段富集型为主;东北部陕北地区主要以中部富集型和顶部富集型为主;盆地中部地区主要以互层型为主;西南部陇东地区主要为底部富集型为主.源岩类型和石油有利区综合分析,揭示出源岩发育样式对石油分布具有控制性作用.姬塬地区底部富集型源下聚集、全段富集型源上源下双向聚集,长6油层组和长8油层组油层组多层系含油;陕北地区顶部富集型和中部富集型源上聚集,长6油层组为主力产层;陇东地区底部富集型源下聚集,长8油层组原油为主力产层,湖盆中部互层型多层复合成藏,源内致密油和源上源下多层系含油.烃源岩纵向分布样式与石油聚集关系不仅是陆相湖盆源藏分布规律的提升,对优选近源—源内油气勘探领域也具有重要意义.In the Mesozoic T-J1 oil system of Ordos Basin,the degree of oil enrichment,main production lay er and source rock distribution have strong regional differences,and there is no systematic study on this difference.The total organic carbon abundance and vertical distribution of the Chang 7 oil formation source layers of 8 long core wells in different areas of the basin were calculated by means of△LogR method.Ac cording to the industrial oil well and the low production well,the favorable oil distribution areas of Chang 8,Chang 7 and Chang 6 oil formation reservoirs are demarcated.The study found that there are five distri bution styles and strong regional differences in the longitudinal direction of source rocks.The Jiyuan area in the northwestern part of the lake basin is dominated by the bottom rich type and the full section rich type,The northeastern Shaanxi region is mainly dominated by the middle rich type and the top rich type.The central area of the basin is mainly the interlayered type,and the southwestern Longdong region is mainly the bottom rich type.The comprehensive analysis of source rock type and oil favorable zone reveals that source rock type has a controlling effect on crude oil distribution.Bottom rich type and the full section rich type are dominant in the Jiyuan area,and multiple layers have oil.In northern Shaanxi,the top rich type and middle rich type accumulate to the upper,and the Chang 6 oil formation was the main production layer.The bottom rich type of the Longdong area accumulates under the source,and the Chang 8 oil formation is the main production layer.The central part of the lake basin is dominated by the interlayered type with multiple layers of production oil.The relationship between the distribution pattern of source rock and oil accumula tion is not only an improvement of the distribution law of the continental lake,but also has important sig nificance for the optimization of the field of near-source-in-source oil and gas exploration.

关 键 词：鄂尔多斯盆地 延长组 烃源岩样式 勘探方向 

分 类 号：TE122.2[石油与天然气工程—油气勘探]