Research On The Properties Of Nano Material-Sulfonate Surfactant Compound System

Nanotechnology has been experiencing exciting continuous growthacross a variety of fields due to its unique propertysuch as size effect and surface effect,and it has been chosen as an alternative method to unlock the remaining oil resources and applied as a new EOR method.This research which proceeded in three aspects of surface tension,adsorption capacity and foam ability aims at developing a new modified nanoparticle system which can be potentially applied in oil field.The improved frozen characterization technology including frozen fixing of foam structure,freezing drying and scanning electron microscope was applied to characterize the existence of nanoparticle in foam structure in microscopic view.The mechanism how the type of ionic surfactant,structure of sulfonate surfactant and the electrical properties of nanoparticle et al.influence the properties of compound system has been researched.At first,SiO2 nanoparticles were activated in situ by nonylphenol decyl sulphonate surfactant(C10-NPAS)and characterized by improved frozen characterization technology in order to figure out the size change and distribution of nanoparticle in foam system and the relationship between particle size and foam lamellar thickness.It shows that through the improved frozen characterization technology,nanopartilces were found in appropriate aggregation and unevendistribution,at the same time,some partly aggregation of nanoparticles presented a physical barrier in the drainage of free liquid and retarded the coalescence process at the bottom layer of foam phase.A further screening of supporting material still needs to be done,even through PVA has excellent performance in fixing the structure of foam.Then,silica nanoparticles(SiO2-NPs),carbon nanoparticles(C-NPs)and oxide modified carbon nanoparticles(modified C-NPs)were carried out in situactivation modification,respectively.The concentrate and the type of nanoparticles,surfactants and electrolyte were mainly investigated toexplore their influence in surface tension,adsorption capacity and foam ability.The results showed that SiO2-NPs,C-NPs and modified C-NPs could be activated in situ by C10-NPAS by hydrogen bondingand released the purpose of using anionic surfactant in modifying negatively charged materials.Through the determination of adsorption capacity,the adsorption capacity of C10-NPAS on SiO2-NPs,C-NPs and modified C-NPs three types of NPs were maintained at 0.19mmol/g,0.15mmol/g and 0.36 mmol/g,respectively;As to different system,the addition of NPs leads to increase of the surface activity in different levels,which perform asthat the absolute value of surface tension slope increases,the critical micelle concentration increases and the minimum surface tension value declines.With the addition of SiO2-NPs,the slope at the inflection point of surface tension-concentration curve increased to1.9 times larger than before,critical micelle concentration(CMC)increased to 5.46 times lager and minimum surface tension value fell by 1.05 m N/m;With the addition of C-NPs,the slope at the inflection point of surface tension-concentration curve increased to 7.12 times larger than before,CMC increased to 3.13 times lager and minimum surface tension value fell by1.86 m N/m;With the addition of modified C-NPs,the slope at the inflection point of surface tension-concentration curve increased to 7.10 times larger than before,CMC increased to 5.60 times lager and minimum surface tension value fell by 1.70 m N/m.The addition of SiO2-NPs and C-NPs bring the positive effects in stabilizing the foam structure,especially for the latter period of defoaming process;Judging by stability of foam,the most suitable compound during the experiment is CNPs=0.5wt%,CNa Cl=1 wt%,CSur=0.3wt%.With the addition of SiO2-NPs and C-NPs,the stability of foam increased by 2.63 times and 2.63 times respectively.At the same time,aliphatic sulfonate(SDBS)is adsorbed in the inner of material,as the unique structure of C-NPs,and the adsorption capacity of branched chain sulfonate(C10-NPAS)trends towards rise with the concentration increasing;The hydrophilicity of C-NPs can be improved by nitric acid oxidation method,the proper condition of oxidation process is under 120s? and the yield is 60.18%.Modified C-NPs shows low surface activity,strongability of stabilizing foam,but poor foamability.It is not obvious to combine foamability and ability of stabilizing foam by just adding C10-NPAS.