Multi-Azimuth Seismic Coherence Fusion Based on the Azimuth Focus Detection

Accurate description and characterization of faults are essential in the exploration and development of oil and gas reservoirs. The multi-azimuth seismic coherences are effective edge-detection attributes, which can quantitatively characterize fault structures at different observation azimuths by quantifying the multi-azimuth similarities of neighborhood seismic traces. The multi-azimuth discontinuous features can be integrated to interpret the fault structures more comprehensively using the multi-azimuth seismic coherences fusion algorithm. However, the accuracy degradation problem generally exists in current coherences fusion algorithms because of the original information loss in fusion and the introduced calculation errors in decomposition and reconstruction. Here, we propose a multi-azimuth seismic coherence fusion method based on azimuth focus detection, which can search the focus regions in multi-azimuth coherences and apply it as a decision map to guide the fusion of multi-azimuth coherences. Compared with previous works, the original information loss problem in the fusion process can be alleviated, and the resolution and discontinuity characteristics of fault structures in the fused coherence can be further enhanced by fusing the information at advantageous observation azimuth. Finally, the field data application indicates that the proposed method is superior to the weighted-average-based and principal-component-analysis (PCA)-based fusion methods in terms of the resolution, the retention of the discontinuity characteristics, and consistency with the well-logging interpretation.