Acoustic Reverse-time Migration using Optimal Staggered-grid Finite-difference Operator Based on Least Squares

作者：Yan, Hongyong^*; Yang, Lei; Liu, Hong

来源：Acta Geophysica, 2015, 63(3): 715-734.

DOI：10.2478/s11600-014-0259-9

• migration
• difference operator
• image quality
• least squares

Reverse-time migration (RTM) directly solves the two-way wave equation for wavefield propagation; therefore, how to solve the wave equation accurately and quickly is very important for RTM. The conventional staggered-grid finite-difference (SFD) operators are usually based on the Taylor-series expansion theory. If they are used to solve wave equation on a larger frequency content, a strong dispersion will occur, which directly affects the seismic image quality. In this paper, we propose an optimal SFD operator based on least squares to solve acoustic wave equation for prestack RTM, and obtain a new antidispersion RTM algorithm that can use short spatial difference operators. The synthetic and real data tests demonstrate that the least squares SFD (LSSFD) operator can mitigate the numerical dispersion, and the acoustic RTM using the LSSFD operator can effectively improve image quality comparing with that using the Taylor-series expansion SFD (TESFD) operator. Moreover, the LSSFD method can adopt a shorter spatial difference operator to reduce the computing cost.

• 出版日期2015-6
• 单位中国科学院大学; 中国科学院地质与地球物理研究所; 中国科学院地质与地球物理研究所兰州油气资源研究中心