双复杂介质条件下的反Q滤波偏移延拓算子研究

地下介质的非弹性吸收衰减效应造成地震资料中深层信号频带窄、能量弱、成像困难,因此需要对地层的非弹性吸收衰减进行补偿。在已有的补偿方法基础上,基于单程波方程,采用与品质因子和频率相关的复速度代替介质真实速度,将粘滞传播算子在频率—空间域采用连分式展开,得到相移项和补偿项,针对连分式的误差,在频率—波数域进行补偿校正,并用逐步累加法解决起伏地表问题。该方法提高了成像精度,有效补偿了由于地层非弹性吸收造成的振幅和频率损失。模型试算和实际资料处理表明,该方法具有一定的适应性和实用性。

A study of inverse Q continuation operator in dual complexity media

Inelastic attenuation characteristics of the layers cause the narrowness of middle and deep signal band, weakness of energy, and difficulty of imaging. It is therefore necessary to compensate the inelastic attenuation of the layers. Based on one-way wave equa-tion, the authors use the complex velocity including quality factor and frequency substitutes for real velocity. Then through expansion viscous continuation operators using continued fraction in F-X domain, the authors obtain phase and compensate term, correct the error caused by continued fraction in F-K domain, and use gradually accumulate method to solve the irregular surface problem. This method could improve the imaging accuracy and compensate the amplitude and frequency attenuation effectively. Model trial and real data pro-cessing show that this method has certain adaptability and practicability.