黏性介质叠前时间偏移方法

The method of prestack time migration in anelastic media

根据衡Q模型,将吸收系数引入黏性介质的相速度中,以相移法为基础,利用稳相点原理,推导基于叠加速度和等效Q值的黏性介质叠前时间偏移的走时和振幅计算公式,研究适合于黏性介质的叠前时间偏移方法.理论数据处理结果表明,该方法具有精确的复杂构造成像能力,能够将黏性补偿结合到偏移过程中,有效恢复深层界面的高频信息;在准确构造成像的同时,提高地震成像的分辨率.

A wave equation based prestack time migration scheme in anelastic media is proposed.Frequency independent Q law and complex phase velocity are used to describe the absorption of seismic energy.Methods for wavefield extrapolation and prestack time migration in complex anelastic media are developed based on phase shift method and stationary point theorem.The synthetic dataset are used to demonstrate that the prestack time migration in dissipation media not only can improve the ability of imaging complicated structure when the velocities mildly vary.The migration section of a 2D dataset proved that incorporation compensation for absorption and dispersion into time migration can effective resume the high frequency information of deep reflection.The spatial wavelet was compressed;the band of frequency was extended;the amplitude of record was increased;the revolution of seismic profile was enhanced.