用逆向递推原理作动校叠加

NORMAL MOVEOUT STACK BY INVERSE RECURSIVE FILTERING

地质矿产部石油物探研究所

在当代石油物探中为了获得丰富的地震信息,野外接收偏移距和接收道数的变化往往比较大。在大偏移距,多道,尤其是超多道接收的情况下,如何利用多道接收的优势进一步解决好浅中层反射的分辨率和信噪比,减少由于动校而造成的浅中层反射同相轴的拉伸畸变问题,已为许多实际工作者所关注。针对这些问题,本文提出了一种方法,即在时间-空间域里用逆向递推原理对CDP道集分段进行整体搬家,从而达到减小动校畸变的目的。本文的研究是以水平层和均匀介质的假设为前提的。从未经切除的理论模型记录的试算中可以看出,用本文提出的方法做动校叠加可以较好地保持波的动力学特征。

In the geophysical prospecting for petroleum at the present day, a great change has been going on in terms of the geophone offset and number of recording channel in order to ensure very plentiful seismic information expected. So it has aroused a profound interest among a large number of geophysicists doing the solid job. As the receiving conditions given are large offset, multichannel (especially in large numbers) , how to take the advantage of"MULTICHANNEL" to help resolve a step further the problems, such as the resolution as well as S/N of shallow and medium layers and minimize the stretch distortion of reflection event, which are caused by NMO. Aiming at these problems, a new technique is advanced.Th-at's to make an "integral move" segment-by-segment for CDP gather in time-space domain by using inverse recursive velocity, so that NMO distortion can be reduced to minimum. The technique presented in the paper is developed on the assumption of simple horizontal layer and homogeneous media. It can be seen from trial computation on the theoretical model record with no muting performed that the kinetic characteristics could be well preserved as a result of using the NMO stack, a technique put forward in this paper.