中国石油大学学报（自然科学版）2025，Vol.49Issue(2)：108-117,10.DOI:10.3969/j.issn.1673-5005.2025.02.009
基于一阶速度-应力方程的起伏地表最小二乘逆时偏移
Least-squares reverse time migration based on first-order velocity-stress wave equation with surface topography
摘要
Abstract
Least-squares reverse time migration(LSRTM)offers advantages such as higher imaging resolution,amplitude fi-delity,and amplitude balancing.However,most existing LSRTM algorithms assume a horizontal surface and struggle to han-dle complex topographic variations.Additionally,LSRTM based on the second-order constant-density acoustic wave equation neglects the impact of density variations on amplitude,making it challenging to achieve high-fidelity imaging in variable-den-sity media.To address these limitations,we derive the perturbation and adjoint equations from the first-order velocity-stress equation under a curvilinear coordinate system.Using the adjoint-state method,we formulate the gradient update equation and implement an LSRTM algorithm based on a body-fitted grid to accommodate undulating surfaces.The results confirm the effectiveness of the proposed algorithm and its adaptability to complex topographies.Specifically,the algorithm successfully mitigates the effects of irregular terrain,suppresses low-frequency noise,recovers high-frequency components,and balances imaging amplitudes,thereby achieving high-resolution,high-fidelity imaging of subsurface variable-density media.关键词
贴体网格/起伏地表/一阶速度-应力方程/最小二乘逆时偏移Key words
body-fitted grid/surface topography/first-order velocity-stress equation/least-squares reverse time migration分类
地质学引用本文复制引用
李振春,卫二祥,黄建平,王九拴,杨静..基于一阶速度-应力方程的起伏地表最小二乘逆时偏移[J].中国石油大学学报（自然科学版）,2025,49(2):108-117,10.基金项目
"十四五"重大项目(2021QNLM020001) （2021QNLM020001）
国家创新群体项目(41821002) （41821002）
国家自然科学基金项目(42074133) （42074133）
长庆油田公司复杂油田地震波成像技术的基础理论研究(2023-10502) （2023-10502）
中石油BGP项目(2023DJ8307) （2023DJ8307）
