TTI介质弹性波FCT有限差分数值模拟

发布时间：2018-05-30 00:07

本文选题：TTI介质 + 有限差分　；参考：《地球物理学进展》2017年04期

【摘要】：TTI(Tilted Transversely Isotropic)各向异性是对地下岩石中广泛存在的规则发育的裂缝和层理的一种有效的弹性近似,基于TTI介质的地震波数值模拟技术是分析地震波在复杂各向异性介质中的传播机理的有效工具.同时,高精度的数值模拟算法也能为后续的逆时偏移技术提供重要的技术支撑.由于TTI介质中地震波方程的弹性参数众多且变化复杂,常规有限差分技术在解决TTI介质正演模拟问题时往往会产生严重的数值频散现象,降低了数值模拟精度.通量校正传输(FluxCorrected Transport,FCT)技术能够有效地压制由空间离散产生的数值频散.本文将FCT技术用于TTI介质中弹性波方程的交错网格高阶精度差分正演,在数值模拟过程中通过对波场进行漫射和反漫射校正实现了空间网格频散的压制.模型模拟结果表明,与常规有限差分算法相比,本文算法能够有效的压制大网格条件下的数值频散,提高模拟精度.
[Abstract]:TTI(Tilted Transversely isotropic anisotropy is an effective elastic approximation of regularly developed fractures and bedding in underground rocks. Seismic wave numerical simulation based on TTI medium is an effective tool to analyze the propagation mechanism of seismic wave in complex anisotropic medium. At the same time, the high-precision numerical simulation algorithm can also provide important technical support for the subsequent inverse-time migration technology. Because the elastic parameters of seismic wave equation in TTI medium are numerous and complex, the conventional finite difference technique often produces serious numerical dispersion phenomenon in solving the forward modeling problem of TTI medium, which reduces the accuracy of numerical simulation. Flux Corrected Transport (FCTT) technology can effectively suppress the numerical dispersion generated by spatial dispersion. In this paper, the FCT technique is applied to the forward modeling of the elastic wave equation in TTI medium with staggered grid high-order precision difference. In the process of numerical simulation, the dispersion suppression of the spatial grid is realized by means of diffuse and anti-diffuse correction of the wave field. The simulation results show that compared with the conventional finite difference algorithm, the proposed algorithm can effectively suppress the numerical dispersion under the condition of large mesh and improve the simulation accuracy.
【作者单位】：中国海洋大学海洋地球科学学院;青岛海洋科学与技术国家实验室海洋矿产资源评价与探测技术功能实验室;中国海洋大学海底科学与探测技术教育部重点实验室;
【基金】：国家自然科学基金项目(41674118) 国家科技重大专项项目(2016ZX05027-002)联合资助
【分类号】：P631.4

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