이방성을 고려한 자동속도분석

초록

Data acquisition including long spread offsets is recently implemented due to the development of exploration techniques. If NMO correction was carried out through the conventional NMO velocity analysis to data acquired at Vertical Transversely Isotropic (VTI) media, the shape of the moveout called “hockey-stick” could frequently appear in the part of long spread offset. This indicates that the conventional NMO velocity analysis dose not provide correct results. Thus, in this study, an NMO velocity analysis module was developed not only considering anisotropy but also extracting an anisotropic parameter η. In addition, the developed module can process huge amount of data like 3D data efficiently and rapidly because it picks the maximum energy points on the semblances automatically. It is important to obtain high-resolution semblances in order to pick the maximum points accurately. Therefore, the developed module uses a bootstrapped differential semblance (BDS) instead of a conventional semblance to provide better resolution. To validate our developed module, it was applied to the numerical and the physical modeling data sets. The extracted velocities and anisotropic parameters were reasonable except in the case of deeply tilted layers, and stacked results were also improved.

키워드