利用LIFT技术衰减海上近道多次波

近道多次波压制是目前海上地震资料处理的一大难题,特别是在浅层气的影响下,近道多次波更是难以压制。常规近道多次波衰减技术在压制多次波的同时,有效信号也受到压制。为此，提出了一种有效衰减近道多次波的LIFT技术,该技术针对有效反射在近中远偏移距均有分布，而近道多次波主要集中在近道的特点,基于局部时窗的AVO原理模拟有效信号,从而达到信噪分离的目的。实际资料处理证实了该技术既能有效衰减近道多次波,又能很好地保留有效信号。

Application of LIFT technology in demultiples of small offset

Near offset multiples are difficult to be removed in offshore seismic data, especially when the data were affected by shallow gas during acquisition. Traditional techniques used for near offset multiple suppression may do harm to the effective signal. In this article, LIFT technique is adopted to attenuate multiples. The main theory is that the near offset multiples can only distribute in near offset gathers whereas effective reflections mainly distribute in medium and large offset gathers. According to AVO theory, this method separates signals and noises in a time window. The effectiveness of this method was verified on real data.