Fault identification method of attribute fusion based on seismic optimized frequency of seismic data

Since faults are commonly significant enrichment region of remaining oil, the elaborate fault characterization is of extreme importance to exploit the remaining oil efficiently. To address the dilemmas of low-accuracy and high-uncertainty in traditional methods of fault characterization, a novel fault identification technique is proposed by fusing diverse seismic attributes from the "optimized" frequency of seismic data, including coherence, inclination, and azimuth. In the proposed method, a "optimized frequency" is confirmed first based on the seismic frequency division by the matching tracking spectrum decomposition technology. Then, three kinds of attributes including coherence, inclination, and azimuth are obtained from the "optimized frequency". Besides, a novel strategy named "seismic sub-volume" is applied herein to eliminate the noise effect. Finally, the above attributes are fused by the HIS (Hue-Intensity-Saturation) transformation to achieve the final fault characterization. A theoretical model test verifies the " optimized frequency" cannot only highlight the reflection features of the subtle faults bigger than three meters, but also avoid the effect of lithologic boundary response and reduce the uncertainty of faults characterization. Furthermore, the proposed method is applied in the oilfield L, and achieves the following remarkable results: the fault system of oilfield L is reconstructed based on the novel " optimized frequency" of 25 Hz; two enrichment areas of remaining oil are detected successfully; two large displacement directional wells along the faults identified by the proposed method are drilled successfully.