The Study On Hydrocarbon Geochemical Index Characteristic And Their Correlations With Gas Hydrate In ODP Typical Stations

Gas hydrate has gained more and more prominence by the world recently.It is a clean energy which is beneficial to cut down on greenhouse gases that produce global warming.United States,Japan and other developed countries has put gas hydrate into their national development strategies and aimed to realize commercial development.U.S.plan to have commercial test drillings in 2015 and Japan had already harvested hydrates gas flow in the Pacific Ocean using their Earth marine exploring ship.Japan plan to have commercial hydrates drilling over a wide area in 2016?2018.China plan to have a break in hydrates exploration and development techniques in 2020 and achieve commercial development in 2030.So there is an urgent need for in-depth and meticulous research on marine gas hydrate geochemical exploration techniques.On the basis of domestic and international marine gas hydrate researches,this article aims to make in-depth study on how free gas hydrocarbons and acidolysis hydrocarbons measured data indicate the occurrence and distribution of gas hydrate in submarine sediments,with the assistance of ODP or IODP cruises data reports.Free gas hydrocarbons are common geochemical index for gas hydrate research,three methods of free gas hydrocarbons index are discussed in this article particularly,including HS,VAC and PCS,to help us have a better understanding of their application effectiveness and significance.In consideration of the shortness of drill cores in most countries including China,acidolysis hydrocarbon geochemical index are raised to study their correlation with gas hydrates for the first time,interpreting their mechanisms and significance.The article also introduced a approach of defining gas hydrate stability zone using acidolysis hydrocarbon geochemical index with the occurrence of authigenic carbonates and turbidites.