| With the continuous optimization of the energy structure in recent years,the proportion of natural gas in the overall energy structure has gradually increased due to its high efficiency,cleanliness,and low pollution.At present,the detected shale gas reserves rank among the top in the world,and the subsequent exploration and development of shale gas has huge potential.However,objective conditions such as poor shale accumulation conditions have brought huge difficulties to shale gas exploitation.Carbon dioxide-enhanced shale gas extraction technology is a possible way to solve the above problems.This paper mainly adopts the occurrence characteristics of the water-carbon dioxide-multi-molecular system in micrometers without molecular interaction,the occurrence characteristics of the water-carbon dioxide-carbon molecular system in the micro under the action of a direct current electric field,and the exchange interaction water-carbon dioxide-The occurrence characteristics of molecular and molecular multi-system in the microcosm.Analyze the influence of different intensities,electric field frequency and electric field direction on the molecular density distribution,hydrogen bond,dipole moment,nonlinear distribution function and interaction energy of the water-hydrocarbon-hydrocarbon molecule multi-system.Without an external electric field: The simulation results of the water-carbon dioxide-methane molecular system on the surface of kaolinite show that water molecules are preferentially adsorbed on the surface of the pores to form a water layer and prevent the adsorption of methane and carbon dioxide molecules.Water molecules reduce carbon dioxide molecules.,The adsorption capacity of methane molecules on the surface of the pores on both sides.As carbon dioxide molecules continue to increase,the adsorption capacity of methane molecules on the pore surfaces on both sides gradually decreases.Under DC electric field conditions: the occurrence characteristics of the water-carbon dioxide-methane molecular multi-system in the microscopic pores.The study shows that the external DC electric field interferes with the adsorption of water molecules on the pore walls and reduces the density of wall water molecules,carbon dioxide molecules and methane.The density distribution of molecules on the wall has increased.In the pores of kaolinite,both carbon dioxide and methane molecules exhibit multilayer adsorption;carbon dioxide molecules are mainly distributed near the wall,while methane molecules are usually located between the two main carbon dioxide molecular adsorption layers.Applying a DC electric field effectively promotes the adsorption of carbon dioxide on the pore wall and enhances the desorption of methane on the pore wall.Under AC electric field conditions: The occurrence characteristics of the water-carbon dioxide-methane molecular multiple system in the microscopic pores have shown that the increase in the intensity of the applied alternating electric field and the increase in the frequency of the electric field can reduce the adsorption capacity of water molecules on the pore surface.As the intensity of the alternating electric field and the frequency of the electric field increase,the number of hydrogen bonds formed between water molecules and the surface of the pores will decrease.The alternating electric field can effectively destroy the hydrogen bonds formed between water molecules and the wall,and the vacant adsorption sites are Occupied by carbon dioxide molecules and methane molecules.Applying an alternating electric field can effectively promote the adsorption of carbon dioxide on the pore wall and enhance the desorption of methane on the pore wall. |
