关键层序界面识别及其在岩性油气藏勘探中的意义——以惠州凹陷珠江组为例  

Key sequence surfaces identification and its significance in the exploration of lithologic reservoirs:a case of Zhujiang Formation in Huizhou Depression

作　　者：芮志锋 林畅松[1] 杜家元 丁琳 李潇 RUI Zhifeng;LIN Changsong;DU Jiayuan;DING Lin;LI Xiao(School of Energy Resources,China University of Geosciences,Beijing 100083,China;Shenzhen Branch,CNOOC,Shenzhen 518000,Guangdong,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中海石油(中国)有限公司深圳分公司,广东深圳518000

出　　处：《岩性油气藏》2019年第1期96-105,共10页Lithologic Reservoirs

基　　金：国家自然科学基金重点项目"南海北部新近纪陆架坡折的发育演化及其对南海盆地动力学过程的沉积响应"(编号:91328201)资助

摘　　要：砂体上倾尖灭油气藏是隐蔽圈闭勘探的重要目标,三角洲前缘砂体形成的砂体上倾尖灭圈闭是重要类型之一。在以三角洲前缘沉积为主构成的三级层序内,高精度层序地层格架的建立以及层序构成分析对于认识砂体上倾尖灭油气藏分布规律及其油气勘探具有重要意义。在珠江口盆地惠州地区针对珠江组以不同尺度的水进界面为界建立了由四级层序构成的高频层序地层格架,其中高频层序界面主要有2种成因类型,即沉积作用转换面和次一级海泛面。三级层序的不同体系域内四级层序的构成特征不同,海侵体系域内的四级层序发育了完整的水退-水进旋回,而发育在高位体系域内的四级层序多由水退半旋回组成。其中三级层序界面和四级层序转换面均控制着砂体的形成与分布,而最大水进面和次一级水进面控制着顶底板或泥质隔层的形成与分布,其构成了"顶板-储集层-底板"的典型"三明治"结构,纵向上相互叠置,形成了砂体上倾尖灭圈闭油气勘探的多套储盖组合,同时也控制着岩性油气藏的平面分布。Sandbody updip pinch-out reservoir is an important target for subtle traps exploration,among which sandbody updip pinch-out trap formed in delta front sandbodies is one of the most important types. In the third-order sequences mainly constituted by delta front sediments,the identification of high-resolution sequence stratigraphicinterfaces and the analysis of sequence composition play key roles in understanding the distribution of sandbody updip pinch-out reservoirs and their hydrocarbon exploration. A high-frequency sequence stratigraphic framework consisting of fourth-order sequence was established for Zhujiang Formation in Huizhou area,the Pearl River Mouth Basin. The high-frequency sequence surfaces include two types,which are sedimentary transition surface and secondary flooding surface. The compositional characteristics of the fourth-order sequence are different in different system tracts of the third-order sequence. The fourth-order sequence developed in the transgression system tract consists of complete progradation and retrogradation cycle,while the fourth-order sequence developed in the highstand system tract mostly consists of progradation half-cycle. The formation and distribution of the sandbodies are controlled by the third-order sequence surface and the fourth-order sequence transition surface,and the formation and distribution of the mud layer are controlled by the maximum water flooding surface and the sub-level water flooding surface. The typical"sandwich"structure is composed of top layer,reservoir and floor layer,which overlap vertically. It forms multiple sets of reservoir-seal assemblage for sandbody updip pinch-out cap oil and gas exploration,also controls the planar distribution of lithologic reservoirs.

关 键 词：高精度层序地层格架 关键界面 控砂控藏 控顶底板 珠江组 惠州凹陷 

分 类 号：TE121.34[石油与天然气工程—油气勘探]