衰减介质中纵波与转换波的分辨率研究

On resolution of PP-and PS-waves in attenuated media

对衰减介质中纵波(PP波)和转换波(PS波)的分辨率问题进行了初步的探讨。在浅层地震勘探中,PS波的分辨率要高于PP波;而当勘探目标大于一定深度,纵波品质因子(Q_P)大于横波品质因子(Q_S),衰减比较明显时,PP波的分辨率将高于PS波的分辨率。如果考虑纵波和转换波随炮检距的变化,也将有类似情况。对于一定的深度,vp和vs的比值,以及Q_P和Q_P比值不同时,PP波和PS波的分辨率随炮检距的变化曲线也将有一交叉点。也就是说,小炮检距情况下,PS波的分辨率较高。

This paper reviewed the studies on resolution of PP-and PS-waves in attenuated media. PS-waves offerbetter resolution than PP-waves for shallow targets. For deeper targets and when Q_P>Q_S, the resolution of PP-waves would higher than that of PS-waves. This holds for the variations of PP-and PS-waves with offset. Whenthe ratio of velocities of PP-and PS-waves is different from the ratio Q_P and O_S , the resolution of PP-and PS-wavesversus offset also has a 'resolution crossover depth', that is, PS-waves offer better resolution at near offset.