一种频域吸收衰减补偿方法

A method to compensate strata absorption and attenuation in frequency domain

1. 吉林大学地球探测科学与技术学院,吉林长春 130026;2. 大庆石油管理局物探公司,黑龙江 大庆 163357

College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China

针对地震信号的吸收衰减补偿问题,在重新建立吸收系数和Q值关系的基础上,提出了一种基于反Q补 偿的分时窗频域吸收衰减补偿方法。首先,逐道抽取地震信号,从浅层到深层选取不同长度的时窗进行傅里叶 变换;然后从非均匀粘弹介质波动方程出发,导出更加准确的吸收系数与Q值的关系,并应用于频域吸收衰减补 偿中;最后将处理得到的频谱反傅里叶变换回时间域重构地震信号。将该方法应用于松辽盆地某地区的叠前和 叠后地震资料的吸收衰减补偿,取得了很好的效果,地震资料的信噪比和分辨率得到了提高。

Aiming at compensating the absorption and attenuation of seismic signal, the paper anew establishes the relationship about absorption coefficient and Q-value, and brings forward a time window method that is base on reverse Q-value to compensate strata absorption and attenuation in frequency domain. The method has the following steps: firstly,extracting every seismic trace,and then choosing different length of time-windows to make Fourier transform from shallow stratum to deep zone. Secondly, from wave equation of viscoelastic medium, we get more accurate relationship about absorption coefficient and Q-val-ue, and apply it to compensate the absorption of seismic signal in frequency domain. Then, the new spectrum is inversely transformed to time domain, and then reconstituting seismic record. We apply the method in the prestack and poststack seismic data of somewhere of Songliao basin, results show that the method can compensate the strata absorption satisfactorily and improve SNR and resolution of the seismic signal.