Experimental Study On The Effect Of Methane Hydrate Formation In Porous Media And Surfactant Compound System

With the development of industry and the increasing demand for energy,related research on natural gas hydrates has become an important research direction in the energy field of countries around the world.In order to understand the mechanism of hydrate formation,scholars at home and abroad have done many studies and found that the formation of natural gas hydrates was affected by various conditions,such as temperature and pressure conditions,mechanical action,external field action,surfactants,porous media and salts.Starting with the static strengthening method,this paper studies the effects of surfactants,porous media and salts on the hydrate formation process,focusing on the surface properties and particle size changes of the porous media and the effect of the addition of artificial seawater on the hydrate formation.From the perspective of induction time,gas storage density and gas storage rate,the strengthening effect and strengthening mechanism of the three factors on the hydrate formation process were studied.The main research is divided into the following aspects:Firstly,a synergistic system of micron-scale calcite and quartz sand with sodium dodecyl sulfate(SDS)was used to study the hydrate formation process.The results show that the promoting effect of this system on hydrate formation is better than pure SDS solution,and calcite is superior to quartz sand in gas storage capacity,up to 127.8V/V.Changes in the surface characteristics and particle size of the porous media will affect the rate and amount of hydrate formation.Secondly,the synergistic system of millimeter calcium carbonate,silica,activated alumina and SDS was studied to study the hydrate formation process.The results show that as the particle size of the same porous medium becomes smaller,the gas storage density of hydrate formation under this system is higher,and the gas storage density of 1 mm calcium carbonate is up to 138.6V/V.The promotion effect of SDS,the surface characteristics and adsorption characteristics of porous media,and the strengthening of the mass and heat transfer processes all promote the rapid formation of hydrates.Finally,adding artificial seawater to the synergistic system found that the double action of salts changed the gas storage density and gas storage rate of the hydrate.Salts below the excessive concentration will promote the formation of hydrates,and above the excessive concentration will inhibit the formation of hydrates.The synergistic effect of porous media,surfactants and salts achieves simultaneous enhancement of the heat and mass transfer processes of the hydrate.