相位替换法剩余时差校正

Residual moveout correction by using phase replacement

中国石化石油勘探开发研究院石油物探研究所,南京210014

Institute of Geophysics Prospecting, SINOPEC, Nanjing 210014

获得到好的叠加剖面和提取正确的AVO信息都要求消除道集上的各种时差,校平同相轴。将现实中使用的各种时差校正方法应用于实际资料时都存在着局限性,在经各种时差校正后的数据上仍有剩余时差存在。本文给出一种以相位替换为基础的时差校正方法,其理论基础是信号的到达时完全包含在信号的相位谱中,通过改变相位谱可达到改变信号到达时的目的。理论上,该方法可以消除任何时差,但由于参考道选取上的困难,实际上仅能用于消除剩余时差,作为静校正、动校正及倾角时差校正的补充。

It is necessary to eliminate any moveout and align lineups in seismic gathers to get good stacked seismic sections and pick AVO information correctly. There are still some residual moveout on the moveout corrected data due to the limitations of various moveout correction methods when they are used on real data. This paper presents a method of moveout correction on the theoretical basis that the arrival times of signals lie within the phase spectrum of seismic trace. Therefore, the arrival times of signals will change if the phase spectrum changes. Theoretically this method could eliminate any kind of moveout, but on account of the difficulty of the selection of reference trace, it can only be used as a complimentary to conventional NMO, DMO, and statics, to eliminate residual moveout. The examples of synthetic and real data demonstrate that this method is helpful in improving the signal to noise ratio and resolution of seismic data and in picking AVO information correctly. Some important points on using this method are also discussed.