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地震相干性在划定地质断层或更小的地层特征上已被证实是非常有效的,那些地层特征包括河道、峡谷、滑塌构造、天然堤、冰槽、排水模式和塔礁等。不聿的是,地震相干性的估算,即定量计算3-D中相邻道之间的相似性或不相似性,对贯穿采集和处理过程始终的相干噪声特别敏感。它们对通过3-D采集和面元处理引入的覆盖次数、炮检距和方位角分布的不同也是敏感的。边界扩展算法进一步加剧了这些线性假象。我们定义采集痕迹为与地面上震源和检波器的几何分布密切相关的任何形式的噪声。现代2-D多次覆盖记录已大大地改进了同期单次覆盖资料上由动校(NMO)拉伸引起的那些强的采集痕迹,而在那些覆盖次数低的浅层剖面和只有6～7次覆盖资料的稀疏的(测网密度不够的)3-D陆上测量的整个剖面上,我们还能看到3-D采集痕迹。利用常规2-D成像处理可以部分地压制时间或深度地震相干切片上的采集痕迹。不幸的是,这种滤波不适用于倾角/方位角图、聚类分析图和其它可能不是连续真实变量的图或有周期值的图。如子波相位图,我们阐述了对于海上和陆上资料采集观测系统,对输入的3-D(t,x,y)时间域或深度域偏移地震数据体进行简单的3-D真振幅倾角滤波,可以非常有效地减小采集痕迹对常规3-D地震特征的不利影响。然而,偏移后资料的3-D倾角滤波常常会消除陡相干图像所必需的断面反射、因此,我们建议,只要有可能尽量在3-D偏移前的叠加数据体上对采集痕迹进行压制,该数据体在深度上的陡断层截断在时间剖面上表现为平缓变化的绕射。
Seismic coherency has proven to be very effective in delineating geologic faults or smaller stratigraphic features that include channels, canyons, slump structures, natural banks, ice troughs, drainage patterns and tower reefs. The estimation of seismic coherency, ie, the quantitative calculation of similarities or dissimilarities between adjacent tracks in 3-D, is particularly sensitive to the consistent coherent noise throughout the acquisition and processing. They are also sensitive to the differences in coverage, offset and azimuth distribution introduced by 3-D acquisition and binning. Boundary expansion algorithms further exacerbate these linear artifacts. We define any form of noise that traces the acquisition as closely related to the geometry of the source and detector on the ground. Modern 2-D multiple-overlay recordings have greatly improved the strong acquisition traces caused by NMO stretching over contemporaneous single overlay data, while in those shallow overlays with low overlay coverage and only 6-7 We also observed traces of 3-D acquisition across the entire cross section of the sparse (insufficient mesh density) 3-D overlay measurements. Capture traces on time-of-magnitude or depth-seismic coherence slices can be partially suppressed using conventional 2-D imaging processing. Unfortunately, this filtering does not apply to dip / azimuth maps, cluster analysis graphs, and other plots that may not be continuous real variables or have period values. For example, the wavelet phase diagram shows that for the observation data acquisition system at sea and on land, the simple 3-D true amplitude of input 3-D (t, x, y) time-domain or depth- Inclination filtering can be very effective in reducing the adverse effects of acquisition traces on conventional 3-D seismic features. However, 3-D dip filtering of post-migration data often eliminates the cross-section reflections necessary for steep coherent images, so we recommend that as long as it is possible to suppress acquisition traces as much as possible on the overlay data body before the 3-D offset , The steep fault truncation of the data body in depth shows a gentle change of diffraction on the time profile.