复杂波场页岩气探区速度分析方法探讨

A Discussion on Velocity Analysis Method of Shale Gas Exploration Area with Complex Wave Field

摘要: XC页岩气探区波场复杂，叠加速度求取困难，采用叠加能量法进行速度分析不能满足处理要求。结合XC页岩气探区地震资料特点，重点针对信噪比低、近地表异常等因素对速度谱质量的影响，提出了针对性的技术，总结出一套精确提取XC页岩气探区地震叠加速度的方法。首先，对原始资料进行净化处理，采用多域、多方法组合压制噪音，提高信噪比；其次，应用多种剩余静校正法联合处理，最大程度减少高频静校正问题的存在，改善地震资料的品质；最后，利用瞬时相位的相关特性，应用统计相位相关法计算速度谱，提高速度求取的精度。该方法获得了较好的成像效果，特别是中深层的构造成像质量有明显改善。

Abstract: The wave field of XC Shale Gas Exploration Area was complex, and the stacking velocity was difficult to obtain. The velocity analysis by superposition energy method could not meet the processing requirements. This paper combined the characteristics of seismic data in the XC Shale Gas Exploration Area, focused on the impact of factors such as low signal-to-noise ratio and near-surface anomalies on the quality of the velocity spectrum, the targeted processing techniques and methods were proposed, a set of methods for precise extraction of seismic stack velocity in XC Shale Gas Exploration Area were summarized. Firstly, the original data were purified and the noise was suppressed by multi-domain and multi-method combination, and the signal-to-noise ratio was improved. Secondly, various residual static correction methods were used for maximally reducing the problem of high frequency static correction and improving the quality of seismic data. Finally, the relevant characteristics of instantaneous phase and the statistical phase correlation method were used to calculate the velocity spectrum, improve the precision of calculating speed. Better imaging results are obtained; especially the quality of structural imaging in the middle and deep layers is obviously improved.