【摘要】 莺歌海盆地中深部地层具有多套超低速层、异常高压、垂向裂隙发育等特点,使得介质具有各向异性,地震波场特征复杂,正演模拟是研究波场特征和观测系统优化的主要手段之一,而海上震源子频带宽、主频高,要求正演模拟网格剖分小,导致计算量大。为此,发展了基于GPU和CPU协同并行的海上三维各向异性介质正演模拟方法,通过将模型分割并分配到不同进程上和任意选择并行计算的方向和每个方向上并行计算的进程个数,不仅可以减小每个进程上内存消耗,而且减少计算时间。简单3D模型的正演模拟验证了该方法可极大地提高计算效率,复杂构造各向异性介质模型中的模拟炮集记录的偏移成像结果验证了方法的可靠性,可适用于任意各向异性介质地震波场正演模拟。更多还原

【Abstract】 There are many ultra-low-speed layers, abnormal high pressure and vertical fracture in deep strata at Yinggehai Basin, which makes anisotropic and structure complex. The characteristics of seismic wavefield are complicated. Forward modelling is one of the main methods to study wavefield characteristics and observation system optimization. However, broad band and high frequency of the source wavelet in marine as well as the small grid size of the model result in a large amount of calculation. To better the calculation, the forward modelling of seismic wavefield in 3 D anisotropic media is developed based on GPU and CPU collaboration parallel in this paper. The 3 D model is divided and assigned to different processes, and the direction of parallel computing and the number of processes in each direction is arbitrarily selected, which can not only reduce the memory consumption in each process, but also reduce the calculation time. The forward modelling of seismic wavefield in a simple 3 D model verifies the method and can greatly improve the computational efficiency. The migration results of the synthetic common shot gather in complex structural anisotropic model verify that the method is reliable and can be applied to the modelling of seismic wavefield in any anisotropic medium.更多还原