摘要
探讨了利用广义 S 变换代替短时 Fourier 变换或连续小波变换,进行吸收衰减补偿的方法。对短时 Fou- tier 变换、连续小波变换、S 变换和广义 S 变换进行了分析和比较,给出了基于广义 S 变换的吸收衰减补偿方法。该方法的实现步骤是：①用广义 S 变换对高信噪比的叠加地震信号逐道进行时频分析；②在每个时间点,根据地层吸收特点提取各个频率的能量吸收衰减因子；③用加权方法对每个时间所对应的各个频率的广义 S 变换系数进行补偿,使各个频率在不同时间的能量相同；④将所有时间各个频率加权补偿的结果重构回地震记录,实现对地层吸收的补偿。模拟结果表明,广义 S 变换时频分析方法能够提高信号时频分布的分辨率。对实际二维地震数据的试算结果表明,基于广义 S 变换的吸收衰减补偿方法能较好地对地层吸收进行补偿,提高地震资料的分辨率,改善地震资料的品质。
Seismic signal time-frequency analysis is performed by substituting the short-time Fourier transform(STFT)or continuous wavelet transform(CWT)with generalized S transform(GST).Based on the properties of S transform (ST),generalized S transform(GST)and the comparisons to STFT and CWT,GST is applied to seismic energy at- tenuation compensation from stratigraphic absorption. Firstly,the high S/N stacked seismic signals are trans- formed to GST coefficients trace by trace;then at each time,the frequency depended attenuation factors are ex- tracted according to the stratigraphic features;the GST co- efficients are weighed by the factors to make each frequency depended energy same at different time.A modeling seis- mic signal is generated to use for test the GST algorithm and its validity.By the proposed compensation schemes, good results have been obtained for real 2D seismic data, which show the method is valid and could compensate ab- sorption very well with the unknown Q value.
出处
《石油物探》
EI
CSCD
2006年第1期9-14,共6页
Geophysical Prospecting For Petroleum
基金
中国科学院知识创新重大项目(KZCX1-SW-18)资助。
关键词
广义S变换
吸收
衰减
补偿
模拟
generalized S-transform
absorption
attenuation
compensation
modeling
