【摘要】 积分法叠前深度偏移及层析成像的核心是复杂介质情况下的地震波走时计算.复杂构造的高精度地震成像需要有稳健的走时计算方法。本文把Nichols提出的用地震波主能量计算走时的方法由二维推广到三维,并推导出三维波动方程Helmholtz形式在球坐标系下用因式分解法求解的差分表达式.三维SEG EAGE盐丘模型的理论走时计算和积分法叠前深度偏移的实践都验证了本文方法的正确性.更多还原

【Abstract】 Travel time calculation in 3-D complicated media is the key for Kichhoff integral migration and tomography. A 2-D main energy travel time calculation approach put forward by Nichols is extended to 3-D. With the help of the factor decomposition finite-difference scheme, the Helmholtz equation in the spherical coordinate system in frequency band can be solved efficiently. Some numerical examples and pre-stack depth migration results on SEG/EAGE salt-dome model demonstrate that this travel time calculation method is very suitable for imaging of complex geological structures.更多还原