Experimental Research On Kinetics Of Marine Gas Hydrate

Simulation experiment is one of the most important areas in the gas hydrates research. These years research on kinetics of gas hydrates is becoming a new hot spot. With these researches we can know the hydrates nucleation mechanism, form conditions of gas hydrates better. In this paper, it analyses several key factors for methane hydrate formation and the process of nucleation of CO₂ gas hydrates.According to the methane hydrates formation experiment, it clearly shows that high frequency vibration can significantly reduce the induction time and accelerate the hydrates formation speed. The increase of temperature and instant gas flowing speed are corresponded to the vibration time very well. Temperature and pressure are two important factors during methane hydrates formation. Temperature affected experiment and pressure affected experiment are carried out respectively in both gas-water system and gas-water-porous media system. Based on the results it is said that under lower temperature and higher pressure hydrates formation speed is faster and the amount of formed hydrate is larger. As for the radius of porous media effect our experiments select four kinds of sea-sand whose pore radius vary between 125-700μm.The results shows that the pore radius we use in the experiments are too large to produce capillary effect which can clag the process of hydrate formation, only if the pore radius is smaller than 60 nm the can produce capillary effect. Besides, our research also mentions the salt-removing effect during methane hydrates formation. The result shows that the amount of gas consumption is the main factor to determine the salt-removing effect. The larger the gas is consumed, the bigger the salt-removing effect is. Na⁺,Ca²⁺ have the most significant variety ratio.Our experiment for CO2 hydrates nucleation adopts electrical resistance method, because the nucleation process can lead to a variety of electrical resistance in the reaction system. According to the experiment result we can tell when the gas hydrates begin to nucleate and by using the experiment data we build up a theory model for nucleation rate which is presented as We also confirm the memory effect of water in hydrates formation.