基于峰值频率法的组合法估计叠前Q值  

A combination method of Q factor estimation based on peak frequency shift method

作　　者：余青露[1] 居兴国[1] 李进[1] 韩立国[2] 

机构地区：[1]中国石油化工股份有限公司石油物探技术研究院 [2]吉林大学地球探测科学与技术学院

出　　处：《地球物理学进展》2015年第4期1833-1839,共7页Progress in Geophysics

摘　　要：为了克服传统的峰值频率法等Q值估计方法精度不高的问题,本文结合了小波能量谱和峰值频率,给出了一种组合法估计叠前Q值的新方法.利用地震波在粘弹性介质中的吸收衰减传播规律,对衰减后的尺度能量谱进行补偿,根据补偿谱和未衰减的参考谱的相似程度与Q值的关系,估计Q值.同时,本文给出一种定量判断小波尺度能量谱相似程度的方法.本文方法首先利用小波变换得到衰减前后的能量谱和峰值频率,结合峰值频率法,给出一个Q值搜索的范围和搜索初值;其次根据本文给出的判定小波能量谱相似程度的方法,搜索出使得参考谱和补偿谱达到最相似时的Q值.理论模型验证了该Q值估计方法的有效性和抗噪性,并且计算效率相对较高.把该方法应用于实际数据,利用估计的Q值进行叠前CMP道集的反Q滤波,验证了本文方法的实际应用的有效性.The precision and efficiency of the traditional Peak frequency method estimate Q is not enough. This paper presents a method of Qfactor estimation,which combinates the wavelet energy spectrum and peak frequency to estimate the pre-stack Qvalue.According to an energy attenuation formula of seismic waves in the wavelet scale domain from the wavelet theory and seismic propagation equation in an elastic medium,we compensate the attenuated amplitude,and get the relation between the wavelet energy amplitude and Q-factor to estimate Q-factor.This paper also gives a method to judge the degree of similarity of wavelet amplitude spectrum. The energy amplitude spectrum and peak frequency is got from wavelet transform. According to the Q value estimated by peak frequency shift method,we can get the Q value search range and initial Qvalue.Then we can use the method of judging the degree of similarity of wavelet amplitude spectrum to search a Q value that make the reference spectrum and compensated spectrum is most similar. Theoretical Model tests the effectiveness and feasibility of this Q-factor estimation method,and this method improve the calculation effciency.Factual data proves the Q value which this method estimates can improve longitudinal resolution of pre-stack CMP gather by means of inversing Qfiltering.

关 键 词：小波能量谱 峰值频率 品质因子Q 谱相似 叠前CMP道集 

分 类 号：P631[天文地球—地质矿产勘探]