浅层小尺度隐伏断层地表勘探的正演模拟及应用

采用二维声波方程有限差分法对浅层小尺度隐伏断层地质模型的地震波场响应进行数值模拟,分别从震源位于断层下降盘顶、断层上升盘顶及断层顶三个不同位置进行正演模拟,对地震波场在断层模型中的传播规律及其地震记录变化特征进行了详细分析。结果表明多个单炮记录的变化对比不仅可以对断层进行快速有效的判断,而且为分析断层几何类型、估计断裂带范围与宽度等方面提供重要的依据。同时将模拟结果应用到实际生产中,取得了较好的应用效果。该方法能有效辅助实际野外工作中对断层的判断,为合理设计观测系统及采集参数设置提供指导,对提高浅层地震勘探现场工作效率和精度具有重要作用。

Forward Modelling and Application of Shallow Small Scale Buried Fault Surface Exploration

Seismic wave field response of shallow small scale buried fault’ s geological model was simulated by using two?dimensional acoustic wave equation finite difference method. The fault model were simulated from three different locations, namely on the top of downthrown side, upthrown side and fault respectively. The propagation rules of seismic wave field in fault model and the variation characteristics of seismic records were analyzed in detail. As a result, it not only identified fault quickly and effectively, but also provided important data to analysis of fault geometry type, the estimate of fault range and its width through the comparison and analysis of multiple single shot seismic records. At the same time, the simulation result was applied to the actual production and it has achieved good application effects. This method can effectively assist fault identification in practical production, and provide significant guidance to rational design of observation system and acquisition parameter set. It has an important role in improving efficiency and accuracy of shallow seismic prospecting.