Study On The Dynamic Mechanism Of Oil-Water-Gas Three Phrase Foam

Foam widely used in the oil and gas exploration applications,such as foam flooding,foam plugging,foam drainage and foam fracturing.This artical is concentrated on content of crude oil to the water phase foam drainage quantity,foam layer pressure and conductivity,and get rid of the influence of the conductivity of liquid and the impact of the foam microstructure.The corrsponding conclusions could be made as follows:(1)The addition of crude oil will affect the raw aqueous foam.Fixing the surfactant,with the increase of oil content,the initial foam volume is significantly lower,but the half-life is improved.Fixing oil content of foam,with the increase of concentration of foaming agent,initial foaming volume increase,there is a maximum half-life of 0.125%(wt)SDS.When the amount of oil is certain,the choice of different surfactants,the comprehensive foaming performance of SDS is much better than that of SDBS.When the amount of surfactant is certain,different oil phase added to the raw aqueous foam are influenced,the initial foam volume of decane is relatively large,the half-life of twelve alkanes is relatively long.The phenomenon of shear thinning occurs with the increase of the shear rate,and the shear stress increases with the increase of the shear rate.(2)For foam free drainage,the conductivity and the pressure of the foam layer decreased with the passage of time.With the increase of oil content,the decline rate of electrical conductivity and pressure has slowed down.The conductivity of the liquid containing oil foam layer gradually increased with time.With the increase of oil content,the growth rate of conductivity of the liquid containing oil foam layer has slowed down.When the amount of surfactant is certain,with the increase of oil content,the stability of foam system has been increased.The liquid discharge volume curve becomes flat,the liquid discharge time increased and the liquid discharge rate decreased.Foam drainage process was observed under microscope,When the oil-water ratio is small,the emulsion is not stable.With increasing oil-water ratio,when the oil-water ratio is certain(more than 3:7),the foam stability has been significantly improved,and the liquid discharge rate has slowed down.(3)The comprehensive foaming property of pure water phase foam decreases linearly with the increase of the concentration of foaming agent,the foam stability of oil phase is slightly worse.From the microscopic point of view,it is found that the Plateau channel of the pure water phase foam is significantly wider than that of the oil phase foam,and the liquid flow rate is much faster.In terms of the foam drainage mechanism,the process of pure water phase foam drainage is divided into two stages,namely,the initial stage of the liquiddischarging phase and the late phase;The liquid discharging process of oil water three-phase foam is divided into three stages,namely,the initial stage of the liquid discharging,the liquid discharging stage and the late stage of the liquid discharging.