Seismic Imaging of Complex Subsurface Structures in the Pohang Offshore Area Using Signal Processing Techniques

In this study, seismic data were acquired using the research vessel Tamhae 2 (KIGAM) to investigate the complex geological structures of the Pohang offshore area in the East Sea. The acquisition setup included a 900-meter streamer with a receiver spacing of 12.5 meters. The seismic source had a volume of 1,254 cubic inches, with a source spacing of 25 meters and an offset range from 75 to 975 meters. To accurately image complex subsurface geological structures, various seismic data processing techniques were applied. These techniques aim to remove different types of noise present in raw seismic data and effectively attenuate multiples. In this study, noise removal was achieved through methods such as low-cut filtering, static correction, trace editing, swell noise attenuation, and random noise attenuation to enhance the signal-to-noise ratio. Additionally, techniques like SRME (Surface-Related Multiple Elimination), SRWEMR (Surface-Related Wave Equation Multiple Removal), predictive deconvolution, broadband de-ghost filtering, and parabolic Radon filtering were employed to eliminate WB (water bottom) multiples, which otherwise impede stratigraphic interpretation. Finally, Kirchhoff time migration was used to image the complex subsurface structures. We confirmed that the signal processing techniques applied in this study effectively removed noise and WB (water bottom) multiples. Additionally, signal processing enabled us to derive a more accurate velocity model. Through the final stack section generated with this velocity model, we could confirm that the complex subsurface structures were well imaged.