一种基于SC-DTW的叠前道集剩余时差校正方法

Prestack gather residual moveout correction based on shape context and dynamic time warping

地下介质通常具有各向异性和非均质性,导致常规速度分析及动、静校正难以拉平地震同相轴,常规处理后的地震道集仍然存在剩余时差,这是AVO属性分析和叠前反演常遇到的难题。基于形状上下文(SC)和动态时间规整(DTW),提出了一种新的叠前道集剩余时差校正方法,并对该方法进行数值模拟和实例分析验证。结果表明:基于SC-DTW的叠前道集剩余时差校正方法具有较好的抗噪能力,对地震波形畸变具有较好的鲁棒性,能够有效消除叠前地震道的剩余时差;处理后的地震同相轴波形连续,振幅特征未改变,可以提高AVO属性分析、叠前反演等地震资料处理解释的准确性。该方法利用叠前道集内各地震道波形的相似性,优选出参考道,并在计算时窗内将道集中的每一道都与参考道进行SC-DTW计算,求取其动态规整路径,进行剩余时差校正,因而具有较好的实用性和推广价值。

Prestack reflection events cannot be flatten by conventional velocity analysis and NMO,statics correction,due to anisotropy and heterogeneity of the subsurface media.This is a difficult problem for AVO attribute analysis and prestack inversion.Based on shape context and dynamic time warping(SC-DTW),a new method of prestack residual moveout correction was introduced and verified by numerical simulation(model)and example analysis.The results show that the residual moveout correction method based on SC-DTWprestack gather has better anti-noise capability,better robustness to seismic waveform distortion,and can effectively eliminate the residual moveout of prestack seismic traces.The continuous waveform of the seismic events and the amplitude characteristics are not changed,which can improve the accuracy of seismic data processing and interpretation,such as AVO attribute analysis and prestack inversion.Using waveforms similarity of prestack gathers,the method optimizes for a reference trace,and run SC-DTW calculation of each trace with reference trace in calculation window,to calculate the dynamic warping path and residual moveout correction.The utility model has better practicability and popularization value.