基于粘声介质的反Q滤波叠前深度偏移方法研究

地层非弹性吸收衰减效应使得地震资料的中深层信号频带窄、能量弱,成像困难,因此需要对介质的非弹性吸收衰减进行补偿。在已有的非弹性吸收衰减补偿方法基础上,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,在频率-波数域进行波场延拓算子推导,并对传播算子中的复根式进行精确展开,来提高延拓算子的精度,从而实现了双域叠前深度反Q滤波偏移,提高了偏移的精确度,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。

Because of the inelastic absorption and attenuation effect,the seismic reflection signals from middle-deep strata are characterized by narrow frequency bandwidth and weak energy,which causes difficulty in seismic imaging of subsurface structure,therefore,the inelastic absorption and attenuation effect caused by stratum medium should be compensated.It terms of the existing methods,based on one-way wave equation,we use the complex velocity relevant to quality factor and frequency to substitute the real velocity of medium,deduce the wave field continuation operators in f-k domain,and accurately expand the complex radicals in propagation operator to improve the precision of continuation operator.As a consequent,prestack depth inverse Q filtering migration in dual domains is realized,which increases the precision of migration and effectively compensate the lost of amplitude and frequency caused by inelastic absorption effect.Model testing and real data processing illustrate the adaptability and feasibility of the method.