琼东南盆地深水区中央坳陷带异常压力分布特征  

Distribution Characteristics of Abnormal Pressure in Central Depression Belt,Deepwater Area,Qiongdongnan(Southeast Hainan) Basin

作　　者：王子嵩[1] 刘震[1] 王振峰 孙志鹏 王兵[1] 刘鹏[1] 陈宇航[1] 曹尚[1] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]中海油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《地球学报》2014年第3期355-364,共10页Acta Geoscientica Sinica

基　　金："十二五"国家科技重大专项(编号:2011ZX05025-002-05)资助

摘　　要：异常地层压力是现今琼东南盆地深水区油气勘探面临的一个重要地质问题。运用最新构建的基于孔隙性岩石静力平衡方程的地层压力预测模型,确定了中央坳陷带异常地层压力分布特征,并分析了不同凹陷超压发育特征存在差异的原因。研究表明:(1)中央坳陷带单井压力剖面存在常压型、单段超压型、超压囊型和旋回超压型4种类型;(2)超压顶界面埋深从陆架向深海、从西向东逐渐增大;(3)纵向上,从浅水区到深水区、由西向东超压跨越层位逐渐增多,从浅层到深层超压强度逐渐增大,但乐东、宝岛和北礁凹陷具有"双层式"超压结构;平面上,以乐东、陵水、松南和宝岛4个凹陷为强超压中心,超压强度向南北两侧(低)凸起逐渐降低。总体上中央坳陷带超压分布具有一定规律性,但是不同凹陷间超压分布特征又具有差异性。这种差异主要受到晚期快速沉降速率、泥岩发育特征、烃源岩成熟度和断裂发育特征等因素的影响。Abnormal formation pressure is currently an important phenomenon in the petroleum exploration of deepwater area in Qiongdongnan Basin. The distribution of abnormal formation pressure in the central depression belt was determined by using the new formation pressure predicting model based on the equation of balanceable stress in the pore-rock, and the factors responsible for different distributions of abnormal pressure in different sags were detected. Some conclusions have been reached： （1） The well profiles of pressure in the central depression belt could be divided into four types, i.e., normal pressure, one segment overpressure, overpressure compartment, and cycling overpressure; （2） The top of the overpressure area becomes deeper and deeper from the continental shelf to the deep sea and also from the west to the east. （3） In the longitudinal direction, from the shallow water area to the deep water area and from the west to the east, the overpressure strides more and more formations, and its intensity becomes higher and higher from the shallow part to the depth;nevertheless, Ledong sag, Baodao sag and Beijiao sag have overpressure structures of “double-layer type”. In the plane, the mighty overpressure area is distributed in Ledong-Lingshui sag and Songnan-Baodao sag, and the overpressure intensity is generally reduced from the center composes of the four sags to both the north and the south （low） uplifts. The distribution of the overpressure in the central depression belt shows regularity on the＆amp;nbsp;whole, but the distribution characteristics of the overpressure in different sags are different, which is caused by the terminal high subsidence rate, the characteristics of the mud, the maturity of the source rock and the features of the faults.

关 键 词：差异性 分布特征 异常地层压力 中央坳陷带 深水区 琼东南盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]