Primary and multiple separation method based on complex curvelet transform
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摘要: 多次波压制方法的研究一直都是地震数据处理中非常重要的一个课题.由于常用的多次波匹配方法主要针对多次波模型和实际多次波存在的振幅或相位的差异进行匹配校正,而无法直接校正多次波模型和实际多次波存在时移误差.本文构建了一种复曲波变换的算法,利用复曲波变换的时移不变性质,通过调整复曲波系数的振幅和相位实现对多次波模型振幅和时移误差的校正.为了更好地保护有效信号,在一次波和多次波分离前,引入一个非线性屏蔽滤波器,可以事先分离出大部分有效波,然后再将剩余部分数据作为输入数据,在复曲波域进行剩余一次波和多次波分离.最后通过模型试算和实际资料处理验证了本文提出的一次波和多次波分离方法的有效性.Abstract: The study of de-multiple methods is a very important in seismic data processing. With increasing difficulties of oil exploration and the enhancement of seismic imaging accuracy, the existence of multiples seriously degrades the signal to noise ratio of seismic data, and interferes the identification of primary waves. Meanwhile, it may also cause some false geological features in seismic sections. Therefore, how to effectively suppress multiple is always a focused topic in seismic exploration.The current multiple suppression methods can be classified into two categories: based on filtering methods and based on prediction-and-subtraction methods. When using wave equation and considering the properties of wave-field propagation, the prediction-and-subtraction methods are suitable for complex seismic data. However, standard matching or subtraction methods can only correct the amplitude or phase errors between the multiple model and actual multiples in the stage of subtraction. As for the misalignment errors, these methods cannot achieve better results. So, a new curvelet transform named complex curvelet transform (CCT) is proposed. Taking advantage of shift invariance property of CCT, we can use the phase and amplitude of the data's and multiple model's CCT coefficients to correct misalignment and amplitude errors between the multiple model and actual multiples. In addition, for the purpose of protecting primary waves further, a non-linear masking filter is applied in advance, which can separate most of primary waves firstly, then recover the remaining primary waves using the CCT-based separation method.To demonstrate the validity of the CCT-based separation method, the shot gathers of a concave model are simulated. Firstly, the non-linear masking filter is applied to separate the primary and multiple with partial primary. After doing a simple L2 norm matching to the multiple, the CCT-based separation method is adopted to obtain the residual primary. Combining the residual primary and the primary separated by the non-linear masking filter, the final de-multiple data is obtained. Comparing to the standard matching methods, such as the pseudo multi-channel matching method, the CCT-based separation method can directly correct the amplitude and phase of the multiple model, and protect the primary greatly while suppressing the multiple.The test on the field data also shows the proposed method is applicable and effective. The tests on synthetic and field data show that in the case of misalignment error existence, taking advantage of the properties of shift invariance and amplitude changing with coefficient of CCT, the phase and amplitude of the multiple model can be corrected directly to fit the actual multiple. The application of a non-linear masking filter can protect the primary better while suppressing the multiple. And the new method is proved to be applicable and effective.
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Key words:
- Multiple suppression /
- Complex curvelet transform /
- Misalignment error /
- Masking filter
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[1] Dong L Q, Li Z C, Yang S C, et al. 2013a. Non-causal matching filter multiple elimination method based on correlation and iteration. Chinese J. Geophys. (in Chinese), 56(10): 3542-3551, doi: 10.6038/cjg20131029.
[2] Dong L Q, Li Z C, Yang S C, et al. 2013b. An improved method of surface-related multiple elimination. Progress in Geophys. (in Chinese), 28(6): 3148-3152, doi: 10.6038/pg20130641.
[3] Fomel S. 2009. Adaptive multiple subtraction using regularized nonstationary regression. Geophysics, 74(1): V25-V33.
[4] Guitton A. 2003. Multiple attenuation with multidimensional prediction-error filters.//73th Annul International Meeting, SEG Expanded Abstracts, 1945-1948.
[5] Herrmann F J, Moghaddam P, Stolk C C. 2008a. Sparsity- and continuity-promoting seismic image recovery with curvelet frames. Applied and Computational Harmonic Analysis, 24(2): 150-173.
[6] Herrmann F J, Wang D L, Hennenfent G, et al. 2008b. Curvelet-based seismic data processing: a multiscale and nonlinear approach. Geophysics, 73(1): A1-A5.
[7] Hu T Y, Wang R Q, Wen S L. 2002. Multiple attenuation of seismic data from South China Sea by using beam-forming filtering method. OGP (in Chinese), 37(1): 18-23.
[8] Li X C, Liu Y K, Chang X, et al. 2010. The adaptive subtraction of multiple using the equipoise multichannel L1-norm matching. Chinese J. Geophys. (in Chinese), 53(4): 963-973, doi: 10.3969/j.issn.0001-5733.2010.04.021.
[9] Li Z C, Liu J H, Guo C B, et al. 2011. Amplitude-preserved multiple suppression based on expanded pseudo-milti-channel matching. OGP (in Chinese), 46(2): 207-210, 231.
[10] Lu W K, Luo Y, Zhao B, et al. 2004. Adaptive multiple wave subtraction using independent component analysis. Chinese J. Geophys. (in Chinese), 47(5): 886-891, doi: 10.3321/j.issn:0001-5733.2004.05.021.
[11] Neelamani R, Baumstein A, Ross W S. 2010. Adaptive subtraction using complex-valued curvelet transforms. Geophysics, 75(4): V51-V60.
[12] Spitz S. 1999. Pattern recognition, spatial predictability, and subtraction of multiple events. The Leading Edge, 18(1): 55-58.
[13] Verschuur D J, Berkhout A J, Wapenaar C P A. 1992. Adaptive surface-related multiple elimination. Geophysics, 57(9): 1166-1177.
[14] Wang Y H. 2003. Multiple subtraction using an expanded multichannel matching filter. Geophysics, 68(1): 346-354.
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