海外深水复杂地质条件下时深转换难点及技术对策

Time-depth conversion difficulties and technical countermeasures for overseas deepwater and complex geological conditions

我国油气勘探向海外进军已成为全球油气勘探的趋势,深水区更是当今油气勘探的热点,然而海外深水区块经常会遇到井少,水深变化大,海底水道发育,重力滑塌,盐底辟活动等问题,采用传统时深转换方法精度低且容易出现"假构造"现象,给时深转换带来新的挑战。本文提出了海底水道填平解释模式及引入"虚拟井"方法,有效提高了时深转换的精度,避免了传统时深转换方法出现的"假构造"现象,通过与实钻深度对比,误差小,成图精度高。最后总结归纳了一套适用于海外深水复杂地质条件下的时深转换方法,对深水区块的时深转换具有一定的借鉴意义。

Today, overseas oil and gas exploration has become a global trend, deep water oil and gas exploration is today＇s hotspot. However, overseas geological conditions of deepwater blocks are often complex, such as few wells, wide variation of water depth, well development of seabed channels, gravitational sliding, salt diaper activity and so on. Under these conditions, low precision and ＂false structures＂ may appear by traditional time-depth conversion. So, seabed channel filling interpretation was put forward, which can avoid ＂false structures＂ appearance converted by traditional time-depth conversion, and introduction of virtual wells further improves the accuracy of time-depth conversion. Comparison with real drilling depth, error is very small and mapping precision was enhanced. Finally, a set of time-depth conversion method was summed up, which has certain instructive meaning for oversea deepwater and complex geological conditions Block time-depth conversion.