Seismic Identification of Small Strike-Slip Faults in Marine Carbonate Strata in Paleouplift Area of Central Sichuan Basin

Fault identification of different scales in marine carbonate rock remains a big challenge for geophysicists. In this paper, aiming at identifying and interpreting fault distribution, especially the small strike-slip faults, it presents the implementation of seismic attributes with the information of fault structure and discontinuity change in mapping the fracture zone distribution in the Sinian-Paleozoic-Permian formation, Gaomo area, Sichuan basin. Technologies such as structural steering filtering, eigenvalue coherence, frequency division coherence and azimuth division coherence, maximum positive/negative curvature attribute, ant body attribute, maximum likelihood fracture identification and PADD (poststack amplitude direction decomposition) are used to describe the faults with different layers, azimuth and scale, which are forming in the types of seismic events dislocation, deflection, micro fault and karst collapse body. Also, the imaging logging is applied to verify the fracture orientation and fracture density of different scales qualitatively and show good coincidence with the results predicted with the seismic attribute. Based on the experiment, it summarizesthree classification and eight stepsgradually controlled fault identification techniques which can distinguish the strike-slip fault of different scales effectively and constructes six types of strike-slip fault structural styles in the central uplift of Sichuan basin. © 2023 China University of Geosciences. All rights reserved.