【摘要】 在地震资料的处理中,逆时偏移方法可以实现复杂构造高精度成像,但计算量和存储量两大问题影响了该方法的实际应用.逆时偏移算法中的边界处理方式的优化可以大大减少存储量,本文讨论了记录波场边界信息的吸收边界和随机边界这两种方法的计算效率和成像效果,提出了吸收边界中只记录边界范围内未衰减单层波场的方法并通过数值实验验证了其可行性,选择了不同的边界策略应用于模型数据和实际资料的处理.结果表明:记录单层波场边界信息的吸收边界的成像效果同传统存储波场历史的方式几乎无差别,但要额外存储每个时刻的波场边界信息;随机边界不需要额外存储波场信息,但会带来边界漫反射影响和计算区域的增加;记录单层波场边界可以明显减少存储量,并且不影响成像效果.更多还原

【Abstract】 In seismic data processing, reverse time migration (RTM) can achieve high resolution imaging for the complex structure, but the problem caused by large amount of computation and storage hinders the practical application of this method. The boundary treatment for the computation of reverse-time migration can greatly reduce the amount of storage, and in this paper, we discuss the computational efficiency and imaging effect of taking absorbing boundary and random boundary, present a new method that only records one unabsorbed layer of wavefield boundary and verify it by numerical experiment, and take different strategies in processing the modeling data and field data. The result shows:RTM imaging by absorbing boundary recording one layer of wavefield boundaries has almost no difference compared to traditional RTM by storing the history of wave propagation, but recording wavefield boundaries costs additional memory; taking random boundary doesn′t need extra memory for storing while leading to an increase in computation and the impact of diffuse by boundary; recording one layer of boundary can reduce the memory dramatically without impacting the imaging.更多还原