Fabrication Of Polyimide Nanoparticles And Investigation Of Foam Stabilized By Polyimide Nanoparticles

Foam has high viscosity.It will defoam in oil,and keep stable in water.Foam has the excellent characteristics of selective water plugging which many other fluids do not have.Because of this,foam has been widely used in many major Chinese oil fields.As foam system is unstable thermodynamic system,seeking a highly efficient sufactant,and high stability performance of foam flooding in the future is a very important task for long-term development of foam.Researchers found foam can be stabilized by nanoparticles in some conditions.This paper introduced a new type of nano-polymer,porous polyimide(PI)nanoparticles in stable foam system research.PI nanoparticles have high temperature stability and good dispersion,is a kind of high prospects of emerging polymer.The author synthesized polyimide nanoparticles by herself.Then author also studied the sizes and morphology of the PI nanoparticles by electron microscope(TEM and SEM).Chemical compositions of nanoparticales has been confirmed by infrared spectrometer.By using thermogravimetric analyzer,author analyzed weightlessness loss of PI nanoparticles under high temperature condition.Porous PI nanoparticles were much stabler than normal PI nanoparticles.Based on different surfactants,the best one,cation surfactant,has been chosen.Then optimization of the surfactant and PI nanoparticles found 1:1 is the best concentration ratio.During the experiments of optimization of the best dispersion,results indicated the best dispersion of concentration ratio.Under this best dispersion of concentration ratio,half-time of foam is the longest,diameters of bubbles are uniform and small,foam stability is perfect.The best dispersion foam can slow liquid velocity,improve dismutation of foam,enhance the viscoelasticity of film.Then author reported foaming properties,stable performance and heat resistance performance of multi-phase foam system.Interfacial rheological property of dispersion and salt resistance of foam were also studied in this paper.Then she observed the foam changes of form under the Foamscan.The experiments resulted that,porous PI nanoparticles can improve the viscoelasticity of liquid film.And they has good stability under the condition of high temperature,is a very fine foam stabilizer.Then oil displacement experiments have been done by using this multiphase foam dispersion.