Abstract: After outlining the basic situation of regional geology and exploration of Hongqikan (HQK) structure, this paper clearly points out existing problems in seismic processing and interpretation, which could be described as low S/N ratio and incorrect imaging, directly related to very complicated faults and structure near the mountain area. In other words, the huge errors at main target layers between the seismic and well-logs tell us that how to get correct seismic image has been a key problem in the area for further seismic processing and interpretation. The main reason for the imaging problem is that traditional imaging technology only for simple cases cannot be applied to the complicated situation like HQK structure. RTM(reverse-time migration), the best imaging technology in the world, has not been utilized and reported in China so far. Hence it is believed that RTM is going to be the most key technology for 3D seismic depth processing and interpretation in HQK. Based on those considerations, this paper focuses on three key technologies, i.e. amplitude-preserved noise reduction, non-linear inversion of interval velocity, and pseudo-spectral double-wavefield reverse-time prestack depth migration (PSDW). They have been applied to HQK processing and interpretation project and achieved the results that are positively far beyond initial prediction. In conclusion, RTM could be used to get the greatest seismic images and successfully solve the problems designed at the very beginning. Besides, RTM experience in HQK will definitely benefit depth processing and interpretation in other complicated areas

Key words: reverse-time prestack depth migration, pseudo-spectral double-wavefield, non-linear inversion of interval velocity, amplitude-preserved noise attenuation, HQK structure, 3D processing and interpretation