转换波地震勘探的若干问题与对策

Some problems and strategies in converted-wave seismic exploration

分析了采集和处理中转换波勘探的若干问题 ,提出了相应的解决方法。研究表明 ,转换波勘探工区选择要有针对性 ;转换波观测系统一般不能直接采用纵波的观测系统 ,要结合转换波传播特点进行设计 ;转换波的横波静校正量 ,可以利用x分量上记录的横波信息来解决 ;为了提高转换波处理精度 ,采用非双曲交互速度分析实现转换波速度分析 ,采用精确公式计算转换点 ,采用非双曲方程进行转换波动校正 ;在转换波叠加时采用与速度比值有关的面元以确保覆盖次数的稳定性。通过一些实例来说明上述问题。

This paper analyzes some problems in converted-wave seismic data acquisition and processing, corresponding strategies are given. Research shows that work area should be selected purposefully. Conventional P-wave geometry can not be directly used in converted-wave exploration. The quantity for shear-wave statics can be derived solely from the shear-wave information in X-component. Velocity analysis by nonhyperbolic equation and interactive method, converted point calculation by exact formula, normal moveout correction by nonhyperbolic equation are adopted to enhance processing accuracy. Stacking bin size of converted-wave is varied to ensure even coverage fold. Some examples are given.