Frozen Natural Gas Hydrate Reservoir And Mineral Fluid Characteristics Analysis In Muli Coalfield Of Qilian Mountain?Qinghai Provence

With the growing exhausted energy sources of conventional oil and natural gas,natural gas hydrate has been taken one of the new energy of the unconventional gas in twenty-first Century.Papers guided by the structural geology,sedimentology,petrology,oil-gas geology,etc.And combined with datas of the geology,drilling and core in research area.Analysis of clay mineral and fluid inclusion of gas hydrate reservoir in the research area as the main method,starting from the informational character of reservoir geology and fluid inclusion,research on the character of reservoir mineral fluid and accumulation systems of natural gas hydrate in Muli permafrost zone of Qilian Mountain.And get following conclusions:?1?Research on natural hydrocarbon gas source migration of gas hydrate reservoir is developing.The study that the character of inclusion petrography and homogenization temperature?T_h?of fluid inclusions shows that there had been at least2 major hydrocarbon migration periods which was corresponded a time of the late Jurassic to early cretaceous?160Ma¹40Ma?in research area in history and a hydrothermal migration period which was corresponded a time of the early cretaceous to tertiary?80Ma²0Ma?.?2?The Raman components of micro laser were CH₄,CO₂,SO₂,HCO₃^-,CO₃^2-,etc.The results of the test show that the different mineral fluid inclusions had different characteristics.?3?Comprehensive research shows.The process of hydrocarbon migration and accumulation in the first two major hydrocarbon fluids in the study area.Despite produced the large amount of oil and gas,the damage of the late structure was not conducive to the preservation of hydrocarbon reservoirs.Migration and hydrothermal activity of high hydrocarbon fluid in third stage,hydrocarbon fluids could migrate and aggregate in the sealing faults and shale fractures,and form the fault reservoir and fractured reservoir.?4?The main types of reservoir study of clay mineral is chlorite,illite,kaolinite,illite smectite mixed layer.Components change with depth shows the change of the relative content of illite is increased with the increase of buried depth,with illite crystallinity,ordered Iraq-smectite,indicated that the diagenesis is the main factor of the formation of the unique characteristics of clay minerals.?5?According to the change of clay mineral characteristics in vertical direction,The Middle Jurassic strata was zoned in diagenesis A-B,the Triassic galede Temple group strata was zoned for late diagenesis.?6?The spatial coupling relationship between fluid charge and hydrocarbon accumulation in hydrate hydrocarbon source fluid and controlling factors of gas hydrate reservoir system in the research area were analysed.And useful exploration and comprehensive discussion of gas hydrate reservoir system in study area had been carried on,Put forward five modes of accumulation of natural gas hydrate in Muli permafrost regions.