转换波振幅补偿

在地震勘探中,为了获得具有真振幅的地震记录,必须对由各种因素影响形成的衰减后的实际地震记录进行振幅补偿.在影响地震波振幅的诸多因素中,除反射系数外,最主要的是波前扩散和吸收的影响.所谓振幅补偿实际上主要是对扩散和吸收的补偿.由于转换波传播路径的不对称性,对转换波波前扩散和吸收影响的计算较为困难.文中考虑转换波传播路径的不对称性,提出计算转换波波前扩散和吸收影响的方法,对转换波的振幅进行补偿,实际资料试验处理结果证明了方法的有效性.

AMPLITUDE COMPENSATION OF CONVERTED WAVE

In seismic exploration , the seismic record which is declining due to various factors should be compensated in order to get the true amplitude. Among various factors affecting the amplitude of seismic record, wavefront divergence and absorption are the key ones,except reflected coefficients. The amplitude compensation of seismic record is actually the compensation for wavefront divergence and absorption.It is difficult to calculate the influence of wavefront divergence and absorption for converted wave because the asymmetry of it's travel line. A new calculation method which consider the asymmetry of travel line is developed. After calculation of the influence of wavefront divergence and absorption on converted wave,amplitude of record is compensated. Test processing of real seismic record in South China Sea showed the method is effective and desirable.