3D4C Data Processing Using Coordinate Recomputation for OBC Data in the Offshore of Pohang, Korea

We conducted 3D Ocean Bottom Cable (OBC) seismic surveys in the offshore area near Pohang, South Korea, for an empirical study on Carbon Capture and Storage (CCS) monitoring. Due to the absence of acoustic transponders, the exact positions of the OBCs during seismic data acquisition were unknown. As a result, utilizing the planned OBC positions for data processing led to a degradation in the quality of the processed seismic images. To improve the quality of the seismic images, we initially employed the adaptive noise cancellation method to eliminate monochromatic noise. Subsequently, we refined the positions of deployed OBCs using the First-Break Picking method based on the Difference Between Multiwindow Energy Ratios (DERs). The results demonstrated enhanced data quality and improved stratigraphic continuity.