南海北部琼东南盆地深水区梅山组一段地震相分析  

THE SEISMIC FACIES ANALYZING OF DEEP WATER AREA OF MIOCENE MEISHAN FORMATION IN QIONGDONGNAN DASIN,NOVTHERN SOUTH CHINA SEA

作　　者：冯杨伟[1,2] 屈红军[3] 张功成 蒲仁海[3] 

机构地区：[1]中国地质调查局西安地质调查中心,陕西西安710054 [2]西安地质矿产研究所,陕西西安710054 [3]西北大学大陆动力学国家重点实验室,陕西西安710069 [4]中海油研究总院,北京100027

出　　处：《矿物岩石》2016年第1期82-95,共14页Mineralogy and Petrology

基　　金：国家自然科学基金项目(41502081);国家科技重大专项项目"南海北部深水区大型生物礁滩分布与成藏条件分析"(2011ZX05025-006);中国地质调查局油气基础地质调查项目(编号12120114083001)

摘　　要：琼东南盆地深水区(约9×10~4 km^2)有钻井6口,过井地震剖面18条,未过井地震剖面50余条,[二维地震测线共约12 000km,测网密度多为6km×8km,局部地区为4km×6km和8km×16km。三维地震区两块面积共约1 700km^2。]针对研究区少井且只有二维与三维地震资料的实际情况,采用盆地浅水区钻井资料与深水区地震资料相结合互相印证,通过识别测井层序与地震层序的界面、制作合成地震记录和标定层位来建立研究区等时层序地层格架。依据地震相外部形态与内部结构、地震反射同相轴的振幅和频率4个参数划分地震相。从单井与连井沉积相分析出发,结合古沉积构造背景和地震属性中的均方根振幅与瞬时频率,通过浅水区已有钻井验证的标准地震相向沉积相转化的标定、将标定的结果运用至盆地深水区、并充分考虑大地构造背景,将地震相转化为沉积相。研究结果表明:琼东南盆地深水区梅山组一段共划分出5大类地震相:前积、楔状、席状、碟状和丘状,沉积环境主要为浅海和半深海,主要发育5种沉积相类型:浅海相、半深海相、碳酸盐岩台地相、生物礁相、碳酸盐岩缓坡相,浅海环境中南部斜坡发育呈近北东—南西向展布的大型斑礁群,南部隆起发育大面积碳酸盐岩台地,台地边缘礁带呈近东西向断续排列,是盆地深水区继碎屑岩发现之后的潜在勘探新领域。There are six deepwater drilling wells,eighteen cross hole seismic sections,and about fifty none-cross hole seismic sections in the deepwater area of Qiongdongnan Basin （about 9 × 104 km^2 ）. The drilling well data in the shallow water area,combined with the seismic data in the deep water area,are used for mutual conformation so as to cope with the lack of information. Stratigraphic framework is established by identifying the logging sequence interface and seismic sequence interface of,obtaining seismic synthetic records and demarcation of horizon. Seismic facies are identified on the base of external form, internal structure, amplitude and frequency of seismic reflection. On the basis of sedimentary facies analysis of single well and multi well section, associated with analysis of palaeo sedimentary-tectonic setting, seismic attribute of root-mean-square amplitude and instantaneous frequency in shallow water are calibrated and used in deepwater,sed- imentary facies of upper and lower segment of Meishan Formation is individually transformed from seismic facies into sedimentary facies. It shows that there are five seismic facies mapped out in deepwater area of Qiongdongnan Basin, including mat-shaped, filling, wedge shaped, foreset, moundy shaped and lenticular seismic facies, and plan of seismic facies. The main depositional environment of Meishan stage was shallow sea and bathyal marine,and the main sedimentary types are shallow sea facies, bathyal facies, carbonate platform facies, biohermal facies and carbonate gentle slope facies. Large patch of northeast to southwest trending reef group develops in the southern gentle slope under the shallow water, and large area carbonate platform develops in southern uplift zone. The reef in the edge of platform occurs along the east to west direction which is the potential exploration area in the Qiongdongnan Basin.

关 键 词：深水区 梅山组 地震相 沉积相 沉积模式 

分 类 号：TE122.2[石油与天然气工程—油气勘探]