动校剩余时差处理方法及应用

The processing method and application of the residual moveout NMO

常规采集和处理后的地震道集经常动校不平,存在剩余时差,对叠加成像、叠前反演和AVO属性等分析存在影响.为拉平地震道集,提出了一种与剩余时差无关的道集拉平方法——绝对值互相关方法.该方法将地震道集的每一道与参考道在选定的时窗内进行绝对值互相关计算,利用相关系数门槛值的控制剔除异常相关系数值,得到剩余校正时移量场,并对其进行平滑处理,最终利用该时移量场校平地震道集.绝对值互相关具有良好的抗噪性,能适应低信噪比道集及道集极性反转等各种异常情况.多个地区的应用表明,该方法能较好地校平叠前地震道集,改善道集的品质,并且具有较好的适应性.

The seismic gathers can not be flatten after conventional processing, and there are often residual movemout.The impact of these exist on seismic imaging,prestack inversion and AVO attribute analysis.this paper presents a kind of method——the absolute value cross-correlation method,that has nothing to do with the remaining difference to flatten the seismic gathers.This method is that every seismic gather perform absolute value of the cross-correlation calculation with reference seismic trace within the selected window.The abnormal correlation coefficient can be excluded by using the correlation coefficient threshold.Then we can abtain the remaining amount of correction shift field and smooth it.Finally,the seismic gathers are flatten by the shift field.the absolute value cross-correlation method has good noise immunity.It can adapt to the low SNR gathers and gathers polarity reversal and other anomalies.The method has been applied in a number of areas.The good effect can be got in seismic gathers flatting and removing the remaining difference.It can improve the quality of seismic gathers and section imaging.