基于曲波稀疏变换的拉伸校正方法

    Stretch correction method based on Curvelet sparse transform

    • 摘要: 动校正是地震数据处理中的重要步骤,但它在校正过程中会产生子波拉伸畸变效应,随着偏移距的增大,会出现主频降低、振幅扩大的现象。由于存在拉伸畸变,同相轴未被拉平,导致非同相叠加,会引起水平叠加剖面的频率失真和分辨率下降,因此,拉伸校正是提高水平叠加剖面分辨率的关键。子波拉伸畸变在曲波稀疏域中是不相干的,可以将拉伸校正视为是一个非线性优化过程。通过度量稀疏域中数据的稀疏性,使用一种快速有效的算法,来优化子波拉伸畸变生成的非线性问题,最终实现消除子波拉伸畸变的目的。曲波稀疏变换拉伸校正方法能够消除由动校正带来的子波拉伸畸变,恢复远偏移距处的高频信息,校平同相轴。综合模型数据和实际资料处理,曲波稀疏拉伸校正方法能够显著提高水平叠加剖面的分辨率。

       

      Abstract: NMO correction is an important step in seismic data processing, but it will produce the wavelet stretching distortion effect in the process of correction. With the increase of offset, the dominant frequency will decrease and the amplitude will increase.Due to stretch distortion, the in-phase axis is not leveled, leading to non-in-phase stacking, which will lead to frequency distortion and resolution decrease of horizontal stacking profile. Therefore, stretch correction is the key to improve the resolution of horizontal stacking profile.The stretching distortion of wavelet is incoherent in the curved sparse domain, and the stretching correction can be regarded as a nonlinear optimization process.By measuring the sparsity of the data in the sparse domain, a fast and effective algorithm is used to optimize the nonlinear problem generated by the wavelet stretching distortion, and finally the purpose of eliminating the wavelet stretching distortion is realized.The curved sparse transform stretching correction method can eliminate the wavelet stretching distortion caused by NMO correction, recover the high frequency information at the far offset and level the in-phase axis.Combining model data and actual data processing, the curved wave sparse stretch correction method can significantly improve the resolution of horizontal superposition profile.

       

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