渤海湾盆地东营凹陷沙河街组四段膏盐层及地层压力分布特征  

Distribution characteristics of evaporates and formation pressure of the fourth member of the Shahejie Formation in the Dongying Sag,the Bohai Bay Basin

作　　者：刘晖[1,2] 操应长[3] 姜在兴[2] 王升兰 王艳忠[3] 徐磊[5] 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]中国地质大学能源学院,北京100083 [3]中国石油大学地球资源与信息学院,山东东营257061 [4]中国海洋石油股份有限公司北京研究中心勘探事业部,北京100027 [5]中国石油天然气股份有限公司大庆油田有限责任公司,黑龙江大庆163000

出　　处：《石油与天然气地质》2009年第3期287-293,共7页Oil & Gas Geology

基　　金：教育部新世纪优秀人才支持计划(NCET);国家"十五"科技攻关项目(2003BA613A-02)

摘　　要：渤海湾盆地东营凹陷古近系沙河街组四段垂向上发育3套膏盐岩,膏盐韵律层具有明显的蒸发成因的沉积序列。膏岩层在平面上呈环状分布,从湖盆中心向盆地边缘依次沉积盐岩-石膏-泥膏岩-碳酸盐岩-泥灰岩-碎屑岩。在声波时差计算地层压力系数和实测压力统计的基础上研究发现,古近系地层压力在垂向上表现为浅层正常压力系统和深层超压系统的"双层结构"。平面上,异常压力的分布范围与膏盐岩的分布具有较好的对应关系。膏盐岩地层的压力封闭和物性封闭的双重封闭机制是东营凹陷沙河街组四段地层超压形成的重要控制因素之一。Three sets of gypsolyte-sah rocks occur vertically in Es4 （ the fourth member of the Shahejie Formation） of the Dongying Sag, the Bohai Bay Basin. The gypsolyte-sah rhythmic units show apparent depositional sequence of evaporation in genesis. On plane view, the gypsolyte-sah rocks are in ring-like distribution, and salt rock, gypsolyte, argillaceous gypsolyte, carbonate, marl, and clastic rock occur successively from the center to the border of the basin. Studies based on formation pressure coefficient calculation through interval transit times and statistics of the measured pressures show that the Paleogene presents vertically a ＂double layer structure＂ with normal pressure at the upper part and abnormal high pressure at the lower part. On plane view, the distribution of the abnormal pressure matches well with that of the gypsolyt-salt-rocks. It is suggested that the gypsolyte-saltdouble seal mechanism of pressure seal and physical property seal is one of the key elements controlling the formation of the abnormal pressure in Es4 in Dongying depression.

关 键 词：地层压力 分布特征 膏盐岩 沙河街组四段 东营凹陷 渤海湾盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]