鄂尔多斯盆地西南缘上三叠统延长组层序地层学与砂体成因研究  

Sequence stratigraphy and genesis of sand bodies of the Upper Triassic Yanchang Formation in the southwestern margin of Ordos Basin

作　　者：刘自亮[1,2] 朱筱敏[2,3] 廖纪佳[4] 陈杰[5] 

机构地区：[1]成都理工大学能源学院,四川成都610059 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [4]西南石油大学,四川成都610500 [5]中国石油长庆油田分公司,陕西西安710018

出　　处：《地学前缘》2013年第2期1-9,共9页Earth Science Frontiers

基　　金：国家重点基础研究发展计划"973"项目"中国西部叠合盆地深部油气复合成藏机制与富集规律"(2011CB201104);国家重大专项"岩性地层油气藏沉积体系;储层形成机理与分布研究"(2011ZX05001-002);国家重大专项"大型油气田及煤层气开发"鄂尔多斯盆地大型岩性地层油气藏勘探开发示范工程(2008ZX05044 1-3-2)和"大型油气田及煤层气开发"项目专题(2011ZX05009-002)

摘　　要：以鄂尔多斯盆地西南缘延长组为例,运用高分辨率层序地层学原理,对延河等露头沉积特征进行深入研究。研究认为不整合面、冲刷侵蚀面、岩性岩相转换面和湖泛面为重要的层序界面,并划分出1个超长期基准面旋回,5个长期基准面旋回及17个中期基准面旋回。延长期东、西两岸发育河流—三角洲沉积体系,东北部主要为曲流河、曲流河三角洲体系;西南主要发育辫状河及辫状河三角洲沉积体系。有利储集砂体主要为水下分流河道成因、水下分流河道—河口坝复合成因、河口坝成因和滑塌浊积扇成因等4种类型。研究认为,随湖平面变化,在基准面升降过程中,可容纳空间(A)与沉积物补给量(S)的比值(A/S)影响不同物源方向沉积体系的分布,并建立了沉积演化分布模式。Taking the Yanchang Formation in the southwestern margin of （）rdos Basin as an example, by using the high resolution sequence stratigraphy theory, this paper studied the sedimentary characteristics of the Yanhe and other outcrops. It is concluded that unconformities, erosion surfaces, lithofacies contrast surfaces and flood surfaces mark the important sequence boundaries. The Yanchang Formation in the study area can be divided into one super long-term base level cycle, five long-term base-level cycle and seventeen mid term base level cycles. It mainly developed braided fluvial and braided delta depositional system in the southwest steep slope, meandering river delta sedimentary system in northeast terraiwrelief and turbidite fan deposits in the deep lake systems. The genesis of favorable sandstone reservoirs can be divided into submarine distributary channel, submarine distributary channel and composite river mouth bar, river mouth and slump turbidite fans. With changing lake level, the ratio of accommodation space （A） over sediment supply （S） affects the distribution of depositional systems from different source directions and the sedimentary evolution distribution patterns, as discussed in the paper.

关 键 词：鄂尔多斯盆地 延长组 三叠统 层序地层 砂体成因 

分 类 号：P618.130.2[天文地球—矿床学]