巨厚松散层煤田三维地震勘探时深转换方法探讨

Probe into coalfield 3D seismic prospecting time-depth conversion under thick soil layer

时深转换是煤田三维地震资料解释中最关键的一个环节,目前常用的时深转换方法是平均速度时深转换法,这一方法在松散层较厚的区域应用易造成煤层底板深度及断层落差误差较大,无法满足勘探精度要求。本文针对勘探区实际情况,对比了平均速度与分层速度时深转换两种方法,经钻孔验证发现分层速度时深转换得到的煤层底板深度准确度较高。

Time-depth conversion is a key link in coalfield three-dimensional seismic information interpretation.Recently,the most commonly used time-depth conversion method is average velocity timedepth conversion.This method used in thick soil layer area can easily cause coal seam floor depth and fault throw＇s high error,which can＇t meet exploration precision.According to prospecting area＇s actual condition,average velocity and layer velocity were compared in time-depth conversion in this paper.The coal seam floor depth obtained from layer velocity time-depth conversion has high accuracy by drilling test.