零相位子波的垂向分辨率

VERTICAL RESOLUTION OF ZERO-PHASE WAVELETS

中国地质大学

本文较系统地讨论了零相位的雷克(Ricker)子波和辛克(Sinc)子波的垂向分辨率,导出了峰值频率与主频、最高频率与主频的关系;导出了两种子波的半宽度(瑞雷准则)及时间分辨率的极限(雷克准则),及与此相对应所能分辨的薄层厚度.从讨论中,我们可得出二种子波具有相同的垂向分辨率和调谐厚度的结论.由垂向分辨率的公式,我们讨论了地震勘探中速度随深度增加的介质中分辨率的变化,提出了提高深层分辨率的可能途径.在地震工作中,我们可以根据勘探目的层的深度及相应的速度资料,提出可能实现的期望的垂向分辨率,算其最高频率或最短波长,这是从采集到处理过程中必须保持的频率.由此,人们可设计高分辨率地震勘探系统.

In this paper, the vertical resolution of Ricker and Sinc wavelets with zero-phase were introduced systimatically. Relations between the pick frequency and the predominant frequency, between the maximum frequency and the predominant frequency were derived. Also derived were: the half-width of the two wavelets (by Rayleigh criterion), the limit of temporal resolution (by Ricker criterion) and the thickness of the thin bed distinguishable. Through study it has been found that the two wavelets have the same vertical resolution and the same tuning thickness.The change of resolution in the medium in which the velocity increasing with depth was examined in accordance with the vertical resolution formula. The possible ways for improving the resolution of the bed in depth were suggested.In seismic survey, both the desired and available resolution and the maximum frequency or the shortest wavelength (which should be preserved both in data acquisition and in data processing) could be derived from the horizon interested and the correspondent velocity. By doing so, a system with high resolution in seismic exploration could thus be workout with satisfactory.