摘要
地震反射波的高频成分直接影响地震成像结果的分辨率和清晰度,60dB高频死亡线的提出使高频成分的获得过程遭受质疑。高频死亡线存在的核心理由是记录仪器中的分频和占位。白噪系数不利于高频信号的振幅提升,频率泄漏不利于低频和高频信号振幅差距的减小,二者被视作高频死亡线存在的理由。因此60dB高频死亡线成为地震数据高频成分是否可记录的界限。数字地震仪中不存在用于地震数据分解的物理部件,同一时刻的多个数值抢占同一尾数的不同数位更是物理不可实现,因此,高频死亡线存在的核心证据失去支撑。此外,按照高频死亡线推算的新疆沙漠区的死亡频率与该区实际地震数据的频率分布大相径庭,更加表明60dB高频死亡线是一个与现实不相符的悖论。
The high frequency components of seismic reflection waves directly affect the resolution and clarity of seismic images.However,the proposal of the cutoff frequency of 60 dB makes the acquisition of high frequency components questionable.The core reason for the existence of cutoff high frequency lies in the frequency division and occupation.The white noise coefficient hinders the increase of the high frequency amplitude,whereas the frequency leakage hinders the reduction of the amplitude difference between the low and high frequencies.These are two additional reasons for the cutoff high frequency.Consequently,the cutoff high frequency of 60 dB becomes the recordable limit of the frequency component of the seismic data.In fact,no physical component exists and no data decomposition takes place in digital seismographs.Moreover,it is physically impossible for multiple values to occupy different digits of the same mantissa at the same time,thus the core basis of the cutoff high frequency loses support.The cutoff high frequency in the Xinjiang desert region is quite different from the frequency distribution of the actual seismic data.This study therefore demonstrated that the cutoff high frequency of 60 dB is a corollary inconsistent with the reality.
作者
唐文榜
李宗杰
吴华
韩革华
綦成兰
姜华方
TANG Wenbang;LI Zongjie;WU Hua;HAN Gehua;QI Chenglan;JIANG Huafang(Beijing Soft-Land Scientific and Technological Development Co.,Ltd.,Beijing 100083,China;Northwest Oilfield Branch of Sinopec,Urumchi 830011,China)
出处
《石油物探》
EI
CSCD
北大核心
2020年第6期831-843,共13页
Geophysical Prospecting For Petroleum
关键词
地震反射波
高频成分
高频死亡线
倍频程带通滤波扫描
白噪系数
频率泄漏
seismic reflection
high frequency components
cutoff high frequency
octave band pass filter scan
white noise coefficient
frequency leakage
作者简介
唐文榜(1942—),男,硕士,教授级高级工程师,长期从事地震勘探数据采集、处理、解释以及地震方法技术的研究工作,Email:wbtangc@qq.com。
