摘要
通过深入分析鄂尔多斯盆地中部华庆地区沉积物源、湖盆底形以及构造事件,深化研究优质烃源岩、成藏动力和成藏史,建立了湖盆中部低渗透岩性大油区成藏模式。上三叠统延长组沉积期鄂尔多斯盆地中部发育典型的坳陷湖盆中部深水区沉积:长7油层组为盆地最大湖泛期的富营养湖盆沉积,位于湖盆中部的华庆地区烃源岩条件优越,具有有机质丰度高、生排烃能力强、分布范围广的特点;长6油层组沉积期为三角洲大规模发育期,在物源供给丰富、多坡折湖盆底形背景下,华庆地区发育三角洲前缘与重力流复合成因的厚层储集砂体,并在有利沉积相和成岩相共同控制下形成大规模低渗透储集层。长6油层组大规模低渗透储集层与长7油层组优质烃源岩配置良好,形成了"生烃增压、近源运聚、大面积充注、油层连续分布"的岩性大油区成藏模式。
Through in-depth analysis of sedimentary source,lake basin shape and tectonic events as well as careful study of high quality source rocks,reservoir-forming force and history in the Huaqing area,Ordos Basin,the accumulation mode of large low-permeability lithologic oil regions in the middle of the lake basin was established.The Ordos Basin is a typical inland depressed basin during the depositional period of the Upper Triassic Yanchang Formation.Rich-nutrient lake-basin sediments are developed in the Chang-7 Member during the maximum flooding period.High-quality source rocks of the Chang-7 Member have the characteristics of high abundance of organic matter,strong ability of hydrocarbon generation and expulsion,and wide distribution in Huaqing in the central basin.Delta is developed extensively in the depositional period of Chang-6 Member.Influenced by rich provenance and the bottom shape of slope break belts,thick layers of reservoir sands originated from the delta front and gravity flow are developed in the Chang-6 Member in Huaqing,and the favorable sedimentary facies and diagenetic facies control the extensive low-permeability reservoirs.The Chang-6 low-permeability reservoirs and the Chang-7 high-quality source rocks have a good association and form an accumulation mode characterized by ＂hydrocarbon-generating pressurization,proximal migration and accumulation,large-area charging,and continuous oil layers＂.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2012年第6期641-648,共8页
Petroleum Exploration and Development
基金
国家科技重大专项"大型油气田及煤层气开发"(2011ZX05044
2011ZX05001-004)
关键词
鄂尔多斯盆地
华庆地区
烃源岩
重力流
低渗透储集层
岩性大油区
Ordos Basin
Huaqing area
source rock
gravity flow
low-permeability reservoir
large lithologic oil region
