摘要
高阶有限差分波动方程叠前逆时偏移方法的基本原理是,从二维1阶双曲型地震波波动方程出发,通过时间上的2阶差分和空间上的任意高阶交错网格差分对该方程进行离散,得到高阶有限差分逆时偏移算子。采用单频双程波动方程计算初至走时,并以此作为叠前逆时深度偏移的成像条件。设计了凹陷模型和断陷模型,对方法进行了验证。模拟结果表明,基于高阶有限差分的波动方程叠前逆时深度偏移方法可以对复杂地层进行准确成像,并能消除由逆时偏移引起的低频噪声。
The principles of wave equation pre-stack reverse-time migration method with high-order finite-difference approach are as follows: starting from 2D first-order hyperbolic seismic wave equation, the equation was discrete by a second-order finite-difference in time and an arbitrary high-order staggered-grid finite-difference scheme in space,the reverse extrapolation operator was obtained; the first-arrival travel time was computed by single-frequency full wave equation and was used as imaging condition for pre-stack reverse -time migration.Designed depression model and rift model verified the method.The numerical results indicate that the approach can image complex formation and remove low-frequency noises caused by reverse-time migration.
出处
《石油物探》
EI
CSCD
北大核心
2009年第5期475-478,共4页
Geophysical Prospecting For Petroleum
关键词
高阶交错网格有限差分法
地震波波动方程
叠前逆时深度偏移
初至走时
成像条件
high-order staggered-grid finite-difference approach
seismic wave equation
pre-stack reverse-time depth migration
first-arrival travel time
imaging conditions
