歧口凹陷歧北斜坡沙三段挠曲坡折体系与岩性油气藏勘探  

Lithologic reservoir exploration of Es^3 flexure slope break systems in Qibei slope of Qikou sag,Bohai Bay,China

作　　者：蒲秀刚[1] 陈长伟[1] 柳飒[1] 周立宏[1] 肖敦清[1] 韩文中[1] 林常梅[1] 侯志[1] 肖枚[1] 

机构地区：[1]中国石油大港油田公司,天津300280

出　　处：《成都理工大学学报（自然科学版）》2011年第6期611-618,共8页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：中国石油集团公司重大专项(2008E-0601)

摘　　要：从斜坡带沉积背景和古地貌特征入手,以高分辨率层序地层格架为单元,采用3D地震、测录井、取心、砂体分布与油气藏特征等资料综合分析的方法,探讨了渤海湾盆地歧口凹陷歧北斜坡沙三段坡折体系特征与砂体分布以及油气藏之间的关系。结果表明,歧北斜坡沙三段受差异沉降、断块翘倾与基底构造影响,总体发育三级坡坪带,在斜坡高部位一级坡坪带的凸起近缘发育侵蚀坡折带,斜坡中低部位发育挠曲坡折带,构成了沙三段低位期侵蚀-挠曲坡折体系。在斜坡区沙三期,盆内物源供砂,沟槽输砂,坡坪控砂,源型聚砂,纵向上可识别出低位、湖扩、高位3个三级旋回与7个四级高分辨率旋回,各层顺斜向上超覆分布,在各级坡坪带发育了辫状河三角洲前缘、远岸水下扇与滨浅湖砂质滩坝等砂体,地层岩性圈闭发育。这些地层岩性圈闭与烃源区近邻,优势输导,富集成藏,叠合连片,是斜坡区地层岩性油气藏勘探的重要对象之一。Starting off with the analysis of the sedimentary background of slope belts and paleogeomorphology,this paper discusses the slope-break system characteristics and the relationship between sand stone distribution and oil-gas reservoir in high resolution sequence stratigraphic unit by comprehensively analyzing the 3-D seismic,logging,core,sand distribution and reservoir characteristic data.In the typical oil-rich Qikou sag of Bohai Bay Basin,there develops a three-grade slope-flat zone on the whole because of differential settlement,fault block tilt and basement structure.In the low systems tract of Es3-2,there develops an erosional-flexure slope break system including an erosional slope break zone which is located on the arch edge of first-grade slope-flat zone in the high part of slope.A classical flexure slope break zone develops in the mid-low part.The exploration and research indicate that the sandstone supplied by inner basin provenance,delivered by groove,controlled by slope-flat,accumulated by type of provenance of Es3 in the slope.In Es3 three third-order cycles and seven fourth-order high resolution cycles can be identified vertically and each layer overlaps upward the slope in order.Braided river delta front,offshore submerged fan and shallow lake dam bar and related lithologic traps develop in the slope break zone at all levels.All these lithologic traps adjoin the source rocks and have dominant migration,are accumulated,highly overlapped and connected each other.They are the important lithostratigraphic reservoir exploration targets in the slope region.

关 键 词：歧口凹陷 坡坪带 坡折体系 沙河街组 地层岩性油气藏 陆相断陷盆地 

分 类 号：TE122.322[石油与天然气工程—油气勘探]