【摘要】 介绍了高阶有限差分求解双程波动方程和完全匹配层吸收边界条件的基本理论原理。根据逆时偏移实用化所面临的技术瓶颈,提出了GPU/CPU异构协同并行方案和震源波场重构存储策略,有效解决了逆时偏移对海量计算和存储的需求。从逆时偏移成像噪声的产生机理出发,根据噪声的传播方向一致特性、大角度特性和低频特性,采用组合压噪流程,建立针对复杂构造成像的实用化叠前逆时深度偏移技术,最大程度地压制偏移噪声、保留有效信号。理论模型测试和实际资料处理表明,该技术能够有效解决复杂地质条件下的地震成像问题,尤其是对盐丘边界和盐下等特殊构造的刻画均有显著效果。更多还原

【Abstract】 We firstly introduced the basic principles of the higher-order finite difference for solving two-way wave equation and PML absorption boundary condition.Aimed at the technical bottleneck of practicability for RTM,we proposed GPU/CPU heterogeneous collaborative parallel scheme and storage strategy of source wavefield reconstruction,which effectively solved the enormous requirements of computation and storage of RTM.Starting from the generation mechanism of noise from RTM,by using integrated denoising workflow according to the consistent propagation direction,wide-angle and low-frequency characteristic of noise,we established practical prestack reverse-time depth migration,which can suppress migration noise and preserve effective signal.The model testing and actual data application results show that the technique can effectively resolve seismic imaging problem at the area with complex geologic conditions,especially for some special structures such as salt dome boundaries and subsalts.更多还原