| Natural gas hydrate,a new type of clean energy,has received extensive attention in various countries of the world.Therefore,there is an urgent need for in-depth and meticulous research on hydrate exploration and development technologies.Hydrocarbon geochemical methods are one of the commonly used hydrate exploration techniques and are of great significance for the investigation and research of hydrates.At present,the International Ocean Drilling Program ODP/IODP mainly obtains free gas in the core of drilling,but the cost of free gas is high,and it mainly reflects the “dynamic” process of hydrocarbon accumulation,and the adsorbed hydrocarbon gas(acid hydrolysis hydrocarbon)in the core can retains the content and change of hydrocarbon gas in each reservoir during the accumulation of oil and gas and the formation of reservoirs.The abnormal hydrocarbon gas content can be obtained from the experimental results to obtain an abnormal zone of light hydrocarbons,thereby the occurrence area of gas hydrate reservoirs can be delineated.In this paper,354 well core samples from typical ODP/IODP hydrate stations were applied for,and the acid gas dissolved in the wells was extracted by an independently developed degassing instrument to systematically summarize the characteristics of inorganic carbon in sediments from different wells.The relationship between the content of acid hydrolyzed hydrocarbons in the hydrate storage area and the correlation between the carbonate content and its isotope characteristics and the characteristics of the acid hydrolyzed hydrocarbon composition was compared in detail,and different indicators in the well were compared with each other.The unity aims to provide geochemical basis for the identification of the best geological conditions and environment conducive to the accumulation of natural dehydrate,and has important research significance and application value for the exploration and development of natural gas hydrates.The study shows that(1)Cold spring carbonates and turbidites with authigenic carbonate properties are often associated with hydrates,and are one of the best geological conditions and environments for the occurrence and development of hydrates.(2)The acidolysis hydrocarbons are geochemical indicators that characterize the retention of hydrocarbons in carbonates.Acid hydrolyzed hydrocarbons have different geochemical characteristics on carbonates and turbidites and contribute to authigenic carbonates.And turbidite recognition.(3)Cold Spring and Methane Leakage The carbonate rock distribution is the response of the anaerobic oxidation of methane(AMO)process and has significant geochemical characteristics that are higher than the average value of the acid and hydrolytic methane and carbonate in the well.(4)The turbidite layer acidolysis hydrocarbon methane is greater than or close to the mean value of the acid hydrolyzed hydrocarbon methane in the well,and has the geochemical characteristics of high-frequency low-amplitude fluctuations.In the process of degassing ODP/IODP samples to obtain acid hydrocarbon,because the degassing device is manual operation,the operation process is complicated and the rate of waste product is high,and the stability of the device is not strong.In view of the good indication of the acid hydrolyzed hydrocarbon to natural gas hydrate,in order to meet the added requirement for the extraction of hydrocarbon hydrocarbon,the acid hydrolyzed hydrocarbon is removed.In this paper,through comprehensive investigation of the principle of hydrocarbon gas pretreatment and instruments at the present stage of gas hydrate,complete automatic instrument modification has been completed,and the testing of various instrument performance tests meet the requirements. |
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