Computation of Common Middle Point seismic sections and their subsequent time migration and diffraction imaging provides very important knowledge about the internal structure of 3D heterogeneous geological media and are key elements for successive geological interpretation. Full-scale numerical simulation, that computes all single shot seismograms, provides a full understanding of how the features of the image reflect the properties of the subsurface prototype. Unfortunately, this kind of simulations of 3D seismic surveys for realistic geological media needs huge computer resources, especially for simulation of seismic waves’ propagation through multiscale media like cavernous fractured reservoirs. Really, we need to combine smooth overburden with microstructure of reservoirs, which forces us to use locally refined grids. However, to resolve realistic statements with huge multi-shot/multi-offset acquisitions it is still not enough to provide reasonable needs of computing resources. Therefore, we propose to model 3D Common Middle Point seismic cubes directly, rather than shot-by-shot simulation with subsequent stacking. To do that we modify the well-known "exploding reflectors principle" for 3D heterogeneous multiscale media by use of the finite-difference technique on the base of grids locally refined in time and space. We develop scalable parallel software, which needs reasonable computational costs to simulate realistic models and acquisition. Numerical results for simulation of Common Middle Points sections and their time migration are presented and discussed.
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机译：共同中点地震剖面的计算及其随后的时间偏移和衍射成像为3D非均质地质介质的内部结构提供了非常重要的知识，并且是后续地质解释的关键要素。全面的数值模拟可计算所有单次地震图，可全面了解图像的特征如何反映地下原型的特性。不幸的是，这种用于真实地质介质的3D地震勘测模拟需要大量的计算机资源，尤其是用于模拟地震波在诸如多孔裂缝性储层等多尺度介质中的传播。确实，我们需要将光滑的覆盖层与储层的微观结构结合起来，这迫使我们使用局部精制的网格。但是，要用大量的多次拍摄/多次偏移采集来解决现实的陈述，仍然不足以提供合理的计算资源需求。因此，我们建议直接对3D Common Middle Point地震立方体进行建模，而不是通过逐层模拟与后续堆叠进行建模。为此，我们基于时空局部精化的网格，通过使用有限差分技术，修改了3D异构多尺度介质的众所周知的“爆炸反射器原理”。我们开发可扩展的并行软件，该软件需要合理的计算成本来模拟逼真的模型和采集。给出并讨论了模拟共同中点截面及其时间偏移的数值结果。
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