High-density migration velocity model building using double path integral
Liang Yao1,2,3, Wang Zhenli1,2, Chen Yuhong4, Li Xueliang1,2, Duan Qiuliang5
1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
2. Key Laboratory of Petroleum Resources Research, Chinese Academy of Sciences, Beijing 100029, China;
3. University of Chinese Academy of Sciences, Beijing 100049, China;
4. Lanzhou Research Center of Oil and Gas Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China;
5. Hoyep Energy Tech Ltd, Beijing 100029, China
Abstract：Migration velocity model building, a key part of seismic migration, plays a vital role in final imaging quality. The high density velocity analysis based on double path integral is an effective automatic velocity picking technique. But migration velocity value calculated by this method is too high, and the manner of selecting reliable velocity is rarely discussed. After analyzing weighted parameter influences on velocity models, we propose to use the curvature calculated by radon transform as weighted parameters. It is an effective solution to balance velocity models. And Coherent threshold is used in CRP gathers to restrain reliable velocities. This solution significantly improves the picked velocity accuracy. These techniques improve the velocity model building based on double path integral. The improved approach can not only obtain high-precision migration velocity model, but also significantly reduce the cost. High-quality imaging results are obtained event in low S/N seismic data. Test results on model and real data show that the proposed approach is an effective way of automatic migration velocity model building.
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