一种基于振幅谱的地震相干属性计算方法
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| Published in | 应用地球物理：英文版 Vol. 12; no. 3; pp. 353 - 361 |
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| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
2015
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| Subjects | |
| Online Access | Get full text |
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| Bibliography: | Coherency, spectral amplitude, C3 algorithm, dip, multiscale Seismic coherence is used to detect discontinuities in underground media. However, strata with steeply dipping structures often produce false low coherence estimates and thus incorrect discontinuity characterization results. It is important to eliminate or reduce the effect of dipping on coherence estimates. To solve this problem, time-domain dip scanning is typically used to improve estimation of coherence in areas with steeply dipping structures. However, the accuracy of the time-domain estimation of dip is limited by the sampling interval. In contrast, the spectrum amplitude is not affected by the time delays in adjacent seismic traces caused by dipping structures. We propose a coherency algorithm that uses the spectral amplitudes of seismic traces within a predefined analysis window to construct the covariance matrix. The coherency estimates with the proposed algorithm is defined as the ratio between the dominant the constructed covariance matrix. Thus, we eigenvalue and the sum of all eigenvalues of eliminate the effect of dipping structures on coherency estimates. In addition, because different frequency bands of spectral amplitudes are used to estimate coherency, the proposed algorithm has multiscale features. Low frequencies are effective for characterizing large-scale faults, whereas high frequencies are better in characterizing small-scale faults. Application to synthetic and real seismic data show that the proposed algorithm can eliminate the effect of dip and produce better coherence estimates than conventional coherency algorithms in areas with steeply dipping structures. Sui Jing-Kun, Zheng Xiao-Dong, and Li Yan-Dong（ 1. Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China.） 11-5212/O |
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| ISSN: | 1672-7975 1993-0658 |