鄂尔多斯盆地延长组剩余压力分布及油气运聚条件

利用平衡深度法研究了鄂尔多斯盆地中生代地层的流体剩余压力分布特征。研究发现,研究区各井下均有剩余压力,其中长₇幅度最大,其次为长₆和长₄₊₅及长₈,剩余压力的分布与已知含油情况分布关系密切,大多数油田在平面上均分布在相应油组剩余压力低值带,纵向上主要分布在异常压力段中的相对低值带,其次为正常压力段。在此基础上分析了主力生油层长₇油组油气运移及聚集条件,指出安塞和盐池两地区是长₂油层聚集区,陇东、白宝、靖边一线以东是长₆油层运移富集指向区,而陇东、白宝、靖边一带是长₈油层运移富集指向区。

Distribution of Residual Pressure and Oil-Gas Migration and Accumulation Conditions of Yanchang Formation in Ordos Basin

The distribution of fluid residual pressure of Mesozoic strata in Ordos basin is studied based on the equilibrium depth method.The residual pressure presented in each well of the studied area is mostly distributed in Chang-7,followed by Chang-6,Chang-4+5 and Chang-8 in turn.The study shows that most oil fields are found in plane in the low-value belt of residual pressure of the corresponding oil layers,and vertically in the relative low-value belt of abnormal pressure segments as well as the normal pressure ones,by which the oil-gas migration and accumulation conditions of Chang-7 layer are analyzed.It is pointed out that Ansai and Yanchi are the oil accumulated areas of Chang-2,the east of Longdong-Baibao-Jingbian is the target area of Chang-6 oil migration and enrichment,while Longdong,Baibao and Jingbian are the target areas of Chang-8 oil migration and enrichment.