Experimental Research On Foam Properties And Drainaging Foam To Recover Gas

Foam fluid is widely used in the field of drainage and gas recovery in water-bearing gas wells due to its advantages of low cost,good effect,and ease of use.However,there are few researches on the basic physical properties of foams at home and abroad,and almost no macroscopic physical properties and physical parameters of foams have been studied in terms of the microscopic mechanism of foams.Therefore,this paper starts with the basic properties of the foam and explores the static and dynamic characteristics of the foam.It is of great significance to the application of the foam fluid in the fields of oil and natural gas.Based on a large number of investigations,this article first designed a static foam analysis experiment and used relays and precise electronic valves to control the amount of liquid discharged;Secondly,the initial foam quality was calculated using the PR equation of state,and the foam quality was deduced from the Plateau boundary.The breakthrough of the individual Plateau boundary was used as a breakthrough to study the overall foam fluid analysis model,and the relationship between foam quality and time was obtained.Liquid experimental data verify the reliability of the model;Subsequently,an experiment was conducted to investigate the effects of different foaming agent concentrations and different salinity on the liquid carrying efficiency.Finally,foam fluids are divided into power-law fluid foams and plastic-fluid foams.The methods for calculating the viscosity and friction coefficient are discussed respectively.On the basis of the effective viscosity and friction calculation method for power-law fluids,foam flow pressures are established.Gradient calculation model,the bubble flow pressure gradient and flow speed relationship.Research indicates:(1)The velocity of the foam in the foam slowly decreases over time and has a negative exponential relationship with time.The results of the analysis of the liquids show that the overall foam solution model has good applicability under low pressure conditions and when the foam quality is greater than 0.75.(2)The initial foam quality model calculated using PR equation of state shows that when the temperature is higher than the gas critical temperature,the foam quality decreases with the increase of pressure.The results calculated by the Plateau boundary method show that the greater the foam liquid film thickness,the greater the foam quality,the smaller the curvature radius of the Plateau boundary,and the greater the foam quality.(3)The experimental results of the foaming agent carrying liquid show that the carrying efficiency of the foam fluid will decrease slightly with the increase of the degree of mineralization of the foaming solution and increase with the increase of the concentration of the foaming agent in the foaming solution,but after the foaming agent is saturated,The increase of the foaming agent concentration has little effect on the liquid carrying efficiency.(4)The foam is shear-diluted during the flow of the bubble-drainage gas bubble,and the pressure gradient of the foam flow decreases with the increase of the flow velocity.