南沙群岛海域北康盆地生物礁高精度层序地层学及其新近纪生物礁层序演化模式  

High-precision organic reef sequence stratigraphy of Beikang Basin and sequence evolution model of Neogene organic reefs in Nansha Islands Sea Area

作　　者：许红[1,2] 陆永潮[3] 施和生 孙和清[1,2] 张莉 蔡瑛[1,2] 杜家元 王嘹亮 陈平[3] 闫桂京[1,2] 

机构地区：[1]中国科学院边缘海地质重点实验室、中国科学院广州地球化学研究所,广东广州510640 [2]国土资源部海洋油气资源与环境地质重点实验室、青岛海洋地质研究所,山东青岛266071 [3]中国地质大学(武汉),湖北武汉430074 [4]中海石油(中国)有限公司深圳分公司研究院,广东广州510240 [5]广州海洋地质局,广东广州510075

出　　处：《热带海洋学报》2009年第2期48-54,共7页Journal of Tropical Oceanography

基　　金：国家南沙专项项目(95-4-KY-05);中国科学院边缘海地质重点实验室开放基金项目(MSGL07-16);国土资源部海洋油气资源与环境地质重点实验室基金项目(MRE200808);国家973项目(2009CB219406)

摘　　要：新近系生物礁油气储层是南海含油气盆地油气勘探两大主力目的层系之一,过去有关其高精度层序地层学和层序演化模式的研究不多。为此,通过对北康盆地2万余公里地震资料的精细解释和钻井资料的综合研究,获得了以下重要成果:1)识别划分出该盆地新近纪11条主要等时界面、7个三级层序和基本层序组。2)描述了生物礁低位体系域、海侵体系域和高位体系域地震反射结构特征。3)提出南海首个中中新世生物礁高精度层序演化模式,代表中中新世(16.3—10.4Ma BP)海宁期(T13—T2)生物礁的剖面形态,含由1个低位体系域层序单元+5个高位体系域层序单元构成的一个典型海进体系域和由1个早期高位体系域层序单元+1个晚期高位体系域层序单元构成的1个典型高位体系域;可见中中新世完整海进-海退旋回生物礁发生、发展和消亡的过程。通过与曾母盆地中新世生物礁解释剖面对比,指出该模式具有区域性古海洋学代表意义。4)通过对L礁、西琛一井和南海-地中海中新世古海洋演化研究,确定研究区中中新世分别发育5—8个海平面升降旋回,形成晚中新世"南中国海事件",具有冰川型海退性质,可与全球和南海北部特别是与"Missinian"事件对比;确定北康盆地乃至南海新近系生物礁形成至逐渐消亡,也是新构造运动与新近纪古海洋事件共同作用的结果。5)指出L礁气田发现有9.8MaBP、13.8Ma BP、14.5Ma BP和15.5Ma BP等多个层序界面,分别系高孔渗层段;同期南海礁型油气圈闭层序界面当为优良储层;若其为油气充满,则油气"高产"或构成"高压气包"。以上成果,将有助于对全球变化及南海古海洋区域响应过程与结果的理解,并对南海的油气勘探有启示作用。Neogene organic reef oil reservoirs are one of the two main target strata systems for petroleum explorations in the South China Sea petroliferous basins. Previously, there was little research on high-precision sequence stratigraphy and sequential evolvement of such target strata. Recently, a precise interpretation of over 20 000km seismic data is carried out, and the drilling data of the basin are comprehensively studied. The following is the important knowledge acquired. 1）Through identification and division, there are mainly 11 Neogene isochronous interfaces and 7 third-order sequence units and basic sequence sets. 2） The seismic reflection configuration characteristics of low-stand system domain, transgressive domain and high-stand system domain of organic reefs are described. 3） The first high-precision model for sequence evolution of the mid Miocene organic reefs in the South China Sea is given, and this sequence shows a corn plete transgressive cyclic process of an organic reef from generation to development and then to extinction during the Haining Period of the mid-Miocene （6.3-10.4 Ma BP）. Of the model, a typical transgressive system domain consists of a low stand system domain （a sequence unit） and a high-stand system domain （five sequence units）, and a typical high stand system domain is composed of an early high-stand system domain sequence unit and a late high-stand system domain sequence unit. Through comparison with the Miocene bioherm interpretation section from the Zengmu Basin, the above mentioned model is of great oce- anographic significance. 4） Through the study on the Miocene paleo oceanographic evolution in the areas of Reef L, Xichen-1 well and in the South China Sea-Mediterranean areas, we find 5 8 glacial regressive cycles, which formed the ＂South China Sea Event＂ in the late Miocene and corresponded to the ＂Missinian E vent＂ in the global eustatic cycles in the Miocene. The ＂South China Sea Event＂ was a joint action of Neo tectonic movements and Neogene o

关 键 词：北康盆地 中中新世 生物礁高精度层序地层学 古海洋事件 层序演化模式 

分 类 号：P736.22[天文地球—海洋地质]