A STUDY ON GEOTHERMICS AND OCCURRENCE OF GAS HYDRATES IN THE NORTHERN SLOPE OF THE SOUTH CHINA SEA

The research on gas hydrates focuses potential new energy sources,greenhouse gases effects,and seafloor instabilities.The South China Sea sediment basins containing a lot of hydrocarbon source rock were a possible carbon reservior because of its tectonics and geophysics conditions suitable for the formation of gas hydrates especially with the latest news that gas hydrates samples were acquired there in 2007.This paper presents research showing the occurrence of gas hydrates in the Northern Slope of the South China Sea using the static mode after analyzing 127 thermal data packages.The significant index is the thickness of hydrate stability zone which is controlled by geothermal gradient,phase equilibrium and ratio of methane contents.The maps of the thickness distribution with three possible combinations are displayed.Based on two assumptions,influences on thickness induced by the parameter changes are discussed through numerical analysis.The calculation indicates that geothermics can influence the occurrence of gas hydrates and the geothermal data is one of the most important tools in the gas hydrates explorations.