一种稳定高效的等效Q值反Q滤波算法及应用

A robust approach of inverse Qfiltering with equivalent Q

提出了一种基于等效Q值的反Q滤波算法,在补偿高频耗散能量的同时,对速度频散造成的相位畸变也进行了校正。该算法通过光滑的阈值控制增益函数实现稳定性控制,在补偿高频时,引入了一种变频带的计算方法,压制由于频率域的折返效应产生的高频噪声。与一般品质因子Q不同,由于在每一样点的吸收补偿是由该点的Q值唯一决定的,可利用扫描方法直接求取等效Q值。对Q扫描后的叠后反射数据采用对数谱比求频率导数的算法求取等效Q值场,避免了薄层调谐对频谱的不利影响。理论测试与实际资料应用的结果表明,等效Q值反Q滤波算法对含噪地震数据是稳健的,可在保持信噪比的同时提高地震资料的分辨率。

We propose in this paper an approach of inverse Qfiltering with equivalent Q.This approach can not only correct phase distortion by velocity dispersion,but also compensate high-frequency energy loss.It is a robust approach because of stable gain functions by smooth thresholds.For high frequency compensation,a variable band scheme is introduced to suppress side-lobe noise.Unlike normal Qfactor,compensation at each point is determined only by equivalent Qat this point which can be estimated by scanning.The approach calculates the derivative of log-spectrum ratio of poststack data to get variable Qfield,which removes amplitude tuning from thin layers on seismic data.Testson synthetic and real data demonstrate that the proposed approach can not only remove noise from seismic data,but also improve data resolution.