Integrated geophysical inversion to investigate two-dimensional fluid distribution in shallow sediments of the Korea Strait

Subsurface fluid distribution in marine sediments, typically manifested through seabed features such as vents and pockmarks, is crucial for understanding geological processes and structural formations. We collected survey data on shallow sediment of the Korea Strait to investigate depositional system of transient zone from onshore to offshore environment. This study examined the spatial distribution of fluid flow within the shallow sedimentary layers of the Korea Strait using integrated geophysical inversion techniques. We correlated well log data with seismic stacked sections to invert density, complemented by amplitude versus offset (AVO) inversion. The correlation value between logs and synthetic property from inversion exceeded 80% which has accurate expectation. Integration of density and AVO attributes revealed distinct fluid-charged regions within shallow sediments. The result displays fluid distribution patterns in lithological transitions between sand- and mud-dominated sediments. The method presented in this study can be expanded and applied to determine the distribution of fluid-saturated areas in shallow offshore sediments in three-dimensional space in the future, and its accuracy needs to be verified by correlating the core log properties together.