Simulation and analysis of the detection effect of seafloor shallow thermal origin gas release by marine resistivity method

Abstract Thermogenic gas is the main type of gas in the shallow seabed, and its release process is the main cause of the greenhouse effect and gas-induced geological disasters. Due to the lack of effective detection methods, the release process of thermogenic gas in shallow seabed sediments is not clear. Based on the phenomenon of thermogenic gas escape near the Yinggehai Lingtou area, this paper constructs a geoelectric model of thermogenic gas release under different gas saturation conditions, conducts numerical simulations using a novel marine resistivity method, and further compares and analyzes the results. The results show that the marine resistivity method can identify characteristics of sediment with lower gas saturation, and the characterization of gas release morphology is better in the lateral direction than in the vertical direction. With the increase of gas saturation, the abnormal features of the profile are enhanced, and the characterization of gas position and size boundaries is more accurate.