拉东投影法三维叠前深度偏移

对地下地质构造进行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，为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中，提出了三维叠前投影偏移算法. 利用拉东投影变换的原理，将整个三维叠前数据体投影到一系列各方向的径向线上，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，形成一系列的独立的二维叠前测线，可采用二维叠前深度偏移成像方法来实现各径向线的叠前偏移，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深度偏移结果. 实际应用表明，用本方法进行三维叠前深度偏移时，深度偏移剖面对横向分辨率有所提高，对陡地层和小断层的成像效果有所改善.

3-D PRE-STACK DEPTH MIGRATION WITH RADON PROJECTION

The main aim of seismic exploration is to correctly image the subsurface structure. Because the azimuth of data collection is not always normal or parallel to the structure trend, there are many difficulties in 3-D seismic processing especially 3-D pre-stack processing. A new imaging method-Radon projection 3-D pre-stack depth migration is presented to solve this problem, which extends the 3-D migration by Radon projection to pre-stack imaging. The full 3-D pre-stack data volume is projected onto a series of pre-stack radial lines, which are migrated with the common 2-D pre-stack depth migration. Then, the reverse projection on depth slice is applied to get the 3-D migrated volume. Real data example shows that this method can improve horizontal resolution of imaging sections and get better images for steep formations and small faults.