拉东投影法三维叠前时间偏移

Radon projection 3-D prestack time migration.

对地下地质构造正确成像是地震勘探的最终目的,由于三维地震资料采集不可能都沿垂直构造走向的方向进行,这就给地震资料的三维处理带来了许多困难。本文将三维叠后拉东投影偏移思想应用于三维叠前处理,提出了三维叠前投影时间偏移算法。利用拉东投影变换的原理,将整个三维叠前数据体投影到各方向的径向线上,使各方位角的构造都包含在其中某条或多条径向剖面上。投影完成后,形成一系列独立的二维叠前径向线,然后采用各种标准的二维叠前时间偏移成像方法来实现各径向线的叠前时间偏移。当各径向剖面偏移完成后,在时间切片上进行反投影,从而最终形成三维叠前时间偏移结果。实际应用表明,用本方法进行三维叠前时间偏移,可明显提高剖面的信噪比,边界反射很弱,并且资料的中深层成像效果较好。

The final object of seismic exploration is correct imaging for sub-surface geologic structures. It brings a lot of difficulties to 3-D seismic data processing , for 3-D seismic data acquisition can't be carried out in direction perpendicular to structural trend. The paper made application of 3-D poststack Radon projection migration to 3-D prestack processing and presented projection 3-D prestack migration algorithm. Using the principle of Radon projection,the method projected 3-D prestack data volume onto a different radial direction, the structure in each azimuth are involved in certain or multiple radial section,forming a series of independent 2-D prestack lines,which can be processed by common 2-D prestack time migration,then,the reverse projection on time slice was applied to get final 3-D prestack time migration data volume. Real data ap- plication showed that using the method for 3-D prestack time migration resulted in obvious improvement of signal-to-noise ratio of the sections with weak reflection from boundary and good image for middle and deep horizons.