定向延迟组合激发正演照明方法及应用

基于波动方程照明分析原理和组合震源激发理论,对二维声波波场进行规则网格有限差分正演模拟,并给出组合震源照明度的计算方法,对于多个震源组合激发,通过改变相邻两个震源之间的激发时间,激发所产生的地震波场会沿着某一确定的方向传播,可以增强地下特定的区域的地质体的照明分析。模型试验结果表明,震源数目越多,激发的地震波最大能量指向越集中,改变震源之间的延迟时间,可以调整波场的传播方向,该方法对于分析简单的二维模型以及复杂的逆冲推覆构造模型和marmousi模型的照明能量分布均适用,对于指导炮点的设计有借鉴意义。

Study on directional illumination method of combined seismic source

Based on the principle of wave equation illumination analysis and combined source excitation theory,the forward modeling of two-dimensional acoustic wave field is carried out by using finite difference method.The calculation method of illumination of composite source is given,for multiple source combinations.By changing the excitation time between two adjacent sources,a seismic wave field propagating in a direction can be obtained,from the directional seismic wave field,which can be used to enhance the illumination analysis of the target body.The model test results show that,the more the source,the more concentrated the energy of the excited seismic waves.Changing the delay time between the source,the direction of wave field propagation can be adjusted.This method can be used to analyze the illumination energy distribution of simple two-dimensional model,complex thrust nappe model and marmousi model.It is of great significance to guide the design of shotpoint.