地震传播的透射损失补偿方法及正演模拟分析

Transmission dissipation compensation method and forward simulation analysis of seismic propagation

为消除波通过一组反射界面时,由于上覆地层的透射损失对振幅的影响,根据广义O′Doherty-Anstey公式,探索了一种利用声波曲线求取透射系数的方法,补偿上覆地层对主要目的层的地震反射振幅的影响,补偿后不仅主要目的层的反射能量增强,而且层间弱信息丰富,使目的反射层的振幅得到恢复。模型试算结果表明,随着地层品质因子Q的减小,透射系数曲线变陡;当地层吸收一定时,随着深度(时间)的增加,透射损失增大。

For reducing effect of dissipation result from transmission in overlying layers on amplitudes when seismic waves pass through reflectors, a method of determining transmission coefficient by acoustic-wave curve is discussed according to general O＇ Doherty-Anstey formula, to be used to calibrate the effect of overlying layers on reflection amplitudes in target layer. After calibration, reflection energy is intensified in target layer and more information is available in interlamination, thus reflection amplitudes are compensated. Computing results from model show that, the curve of transmission coefficient becomes steeper with quality factor Q decreasing. When stratum attenuation is constant, dissipation resulted from transmission increases with depth or time.