让纳若尔油田盐下速度场的研究

Velocity Field Estimation and Application in the Subbasalt of Zanor Oilfield

让纳若尔油田位于滨里海盆地东缘,受浅层盐丘的影响,导致盐下目的层出现"上拉"和"假断层"现象。从分析盐丘对目的层速度谱资料的影响出发,通过校正异常均方根速度谱,结合大量井分层资料?声波测井和VSP资料,运用层位控制法建立速度场。同时对垂向比例时深转换和射线偏移时深转换进行探讨,认为在该工区盐丘"上拉"作用是影响盐下目的层构造假象的主要因素,采用垂向比例法时深转换形成构造图可恢复真实构造。通过与工区未参与成图的3口井的分层数据对比,其误差控制在15m以内,因此,层位控制法建立速度场和垂向比例时深转换可应用于让纳若尔油田构造成图。

Zanor Oilfield locates in the eastern margin of Pre-Caspian.Being affected by the impact of shallow salt domes,the target zone underneath the salt domes causes the 'pull-up' and 'pseudofault' phenomenon.The velocity field is established through a process of correcting abnormal in RMS velocity spectrum firstly in combination with hierarchical data,acoustic logging and VSP data.Meanwhile,by comparing vertical time-depth conversion with offset ray time-depth conversion,and it is assumed that the 'pull-up' is the main factor of false structure in the target zone.By using vertical scaling method,the precise structural map is ultimately obtained,with mapping technology,the error can be controlled in 15m.Thus,it is confirmed that this method can be applied in mapping Zanor Oilfied.