基于高低频联测的常规检波器数据低频振幅和相位同时恢复方法

Low-frequency amplitude and phase simultaneous recovery of conventional geophones data based on joint deployment of high-and low-frequency geophones

常规检波器对地震信号产生振幅和相位两方面畸变,已有的补偿方法虽然使低频地震信号的振幅畸变有所改善,但其相位畸变仍然存在。这种相位畸变在时间域体现为某些频率出现由检波器引起的时移,明显地影响了频率成分丰富的地震信号。本文提出的基于高低频联测的反褶积低频恢复方法,通过将常规检波器数据转换为目标低频检波器数据,从而实现同时恢复常规检波器数据的低频振幅和相位的目的。此方法以少量高低频联测点为参考道,联合参考道的低频检波器和常规检波器数据通过反褶积构建反滤波器,并通过褶积将反滤波器应用于所有常规检波器数据以实现低频恢复。为应对实际资料中各类噪声,将从不同参考道获得的常规检波器低频恢复数据进行叠加,可以提高低频恢复方法的抗干扰能力和计算稳定性。数值实验和实际资料应用都表明,本文方法可有效恢复常规检波器数据的低频振幅和相位,达到与目标低频数据较好的符合效果,且该方法具有实施简捷、效果稳定和抗干扰能力强的特点。

Seismic signals recorded by conventional geophones have amplitude and phase distortion.Amplitude distortion can be partly recovered by amplitude compensation,but phase distortion still remains uncorrected.This phase distortion causes seismic wave time shift at certain frequency in the time domain and has significant impacts on seismic waves of rich frequency content.Therefore we propose a deconvolution low-frequency recovery method based on the joint deployment of highand low-frequency geophones.The method utilizes high quality low-frequency data acquired by the low-frequency geophones as the reference and constructs the inverse filter by calculating the spectral ratio between the high-and low-frequency geophone data.The low-frequency amplitude and phase of conventional geophone data will be recovered when deconvolving the inverse filter on the conventional geophone data.We stack all conventional geophone data recovered by individual reference trace to increase the denoising capability and computation stability.Numerical and field data applications show that conventional geophone data recovered by the proposed method match very well with the target low-frequency data,and the proposed method is characterized by easy-use,stable result,and noise-resistance.