多参数拟合匹配追踪动校正方法及其应用

A multi-parameters fitting approach for matching pursuit moveout correction and its application

  • 摘要: 【目的和方法】动校正(NMO)是地震数据处理的核心环节,但常规方法在处理大偏移距或广角数据时易引发子波拉伸畸变,导致叠加质量下降及振幅随偏移距变化(AVO)分析失真。匹配追踪动校正(MP-NMO)虽能缓解拉伸效应,却因同相轴交叉问题造成横向不连续,为此,提出一种基于多参数拟合的改进型匹配追踪动校正方法。在匹配追踪分解中,对同一反射界面不同偏移距的子波振幅、频率及相位进行三次多项式拟合,消除局部异常干扰;以二阶时距曲线为初值,结合自适应时间扫描策略,在动态窗口内搜索最优反射波到达时间,避免高阶时距方程求解的复杂性;引入Morlet复子波多尺度扫描,增强抗噪性与频带适应性。【结果】理论模型表明,改进方法有效改善了大偏移距子波拉伸,振幅与频率误差分别低于5%,较传统匹配追踪(误差达40%)提升90%以上,且抗噪性增强,7次迭代内即可收敛。实际资料处理中,浅层大偏移距道集的同相轴连续性改善,叠加剖面分辨率提升,0.8~1.7 s关键层段成像更为清晰。【结论】研究成果为复杂构造区地震资料的高保真处理提供了技术手段,尤其适用于AVO/AVF属性分析和各向异性反演。

     

    Abstract: Objective and Methods Normal moveout (NMO) correction is a core step in seismic data processing. However, conventional methods often cause wavelet stretching when processing wide-angle or long-offset seismic data, leading to degraded stacking quality and distorted amplitude variation with offset (AVO) analysis. While matching pursuit NMO (MP-NMO) can mitigate stretching effects, it suffers from lateral continuity due to overlapping seismic events. To address this limitation, this study proposes an improved MP-NMO method based on multi-parameters fitting. During matching pursuit decomposition, cubic polynomial fitting is applied to the amplitude, frequency, and phase of wavelets from the same reflector across different offsets, eliminating local anomalies. A second-order time-distance curve is used as the initial value for adaptive time scanning within a dynamic window to determine optimal arrival times, avoiding the complexity of higher-order traveltime equations. Additionally, multi-scale Morlet complex wavelet scanning enhances noise robustness and frequency adaptability. Results Theoretical tests demonstrated that the proposed method significantly reduces wavelet stretching at long offsets with amplitude and frequency errors below 5%, which is more than 90% higher than traditional matching pursuit NMO correction (error up to the 40% ). Noisy model test indicates this method exhibits robustness against noise and the convergence can be achieved with 7 iterations. Field data applications show that enhanced continuity in shallow long offset gathers and improved resolution in stack sections, making the events between 0.8 to 1.7 seconds more clearer. Conclusions This method provides a high-fidelity solution for seismic data processing in complex structural areas, particularly benefitting AVO/AVF attribute analysis and anisotropic inversion.

     

/

返回文章
返回