地震散射波的高精度数值模拟与振幅分析

摘要

随着地震勘探要求和技术的不断提高,散射波地震勘探方法逐渐引起人们的重视,尤其在构造复杂地区的高精度勘探中,散射波理论具有广泛的应用前景.本文在讨论了现阶段几种散射波数值模拟方法的利弊后,设计了一种基于微扰论的FK域积分法,在散射场的二次震源和空间能量衰减处理两方面做了改进,其计算精度和效率均得到了提高.此外,采用该算法针对散射波动力学进行了正演模拟试算,从扰动介质空间分布和扰动量两个角度定量地分析了散射波振幅动力学方面的特征.在此基础上得到了五个经验常数,并给出了对应的计算公式和物理意义,通过这五个常数可以划分散射波不同形态的动力学特征.%The scattered wave seismic method is now well appreciated and developed with the advancement of technology and requirement of seismic survey. Particularly in high-precision prospecting of complicated structure area, it has broad application prospect. Different current numerical modeling of scattered wave has their advantages and disadvantages. This paper has designed a method of Integration in FK domain based on perturbation theory to solve scattered field, which could obtain scattered field by integration in FK domain after get the total wave field. It has improved the data source of scattered field and the processing of space energy. The computational accuracy and efficiency of scattered field have got better. In addition, based on the algorithm a forward modeling test is carried out for the dynamics of scattered field. The features of kinetics of scattered wave amplitude are analyzed quantitatively from the perspectives of space distribution of perturbing body and disturbance quantity. Based on this, it obtains five experiential constants and provides the corresponding formula and physical significance. Scattered wave could be classified into different dynamical characteristics by the constants.