Effect of alumina and silica nanocomposite based on polyacrylamide on light and heavy oil recovery in presence of formation water using micromodel

Increasing world request for energy has made oil extraction from reservoirs more desirable.Many novel EOR methods have been proposed and utilized for this purpose.Using nanocomposites in chemical flooding is one of these novel methods.In this study,we investigated the impact of six injection solutions on the recovery of light and heavy oil with the presence of two different brines as formation water using a homogenous glass micromodel.All of the injection solutions were based on a 40,000 ppm Na Cl synthetic seawater(SSW),one of which was additive free and the others were prepared by dispersing nanocomposite silica-based polyacrylamide(NCSP),nanocomposite alumina-based polyacrylamide(NCAP),the combination of both nanocomposites silica and alumina based on polyacrylamide(NCSAP),surfactant(CTAB)and polyacrylamide(PAM)with a concentration of 1000 ppm as additives.The Stability of nanocomposites was tested against the salinity of the brine and temperature using salinity and DSC tests which were successful.Alongside stability tests,IFT,contact angle and oil recovery measurements were made.Visual results revealed that in addition to the effect of silica and alumina nanocomposite in reducing interfacial tension and wettability alteration,control of mobility ratio caused a major improvement in sweeping efficiency and oil recovery.According to the sweeping behavior of injected fluids,it was found that the main effect of surfactant was wettability alteration,for polyacrylamide was mobility control and for nanocomposites was the reduction of interfacial tension between oil and injected fluid,which was completely analyzed and checked out.Also,NCSAP with 95.83%and 70.33%and CTAB with 84.35%and 91%have the highest light oil recoveries at 250,000 ppm and 180,000 ppm salinity,respectively which is related to the superposition effect of interactions between nanocomposites,solution and oil.Based on our results it can be concluded that the most effective mechanism in oil recovery was IFT reduction which was done by CTAB reduction also by using a polymer-based nanocomposite such as NCSAP and adding the mobility control factor,the oil recovery can be further enhanced.In the case of heavy oil recovery,it can be concluded that the mobility control played a much more effective role when the PAM performed almost similarly to the CTAB and other nanocomposites with a recovery factor of around 17%.In this study,we tried to investigate the effect of different injection solutions and their related mechanisms on oil recovery.

Experimental study on using SiO_(2) nanoparticles along with surfactant in an EOR process in micromodel

Surfactant flooding is a common chemical method for enhancing oil recovery.Recently,the simultaneous application of nanoparticles and chemical substances has been considered for improving the efficiency of EOR processes.In the present study,the microscopic and macroscopic efficiency of oil recovery in a linear micromodel in three injection cases of Sodium dodecyl sulfate(SDS)as an anionic surfactant,SiO_(2) nanoparticles,and simultaneous injection of nanoparticles and surfactant was investigated.In our study,adding the nanoparticles along with SDS(2000 ppm)decreased Interfacial tension by 84%,while the figure was 74%and only 10%when the surfactant and the nanoparticles were used alone,respectively.Seemingly,although the nanoparticles alone could not reduce IFT values,adding them to surfactant solution could strongly decrease the interfacial tension between oil and water,leading to enhancement of oil recovery.However,our findings showed that an optimum concentration of nanoparticles in surfactant solution must be used.In this regard,in low concentrations of nanoparticles,they were attached to the interface and IFT decreased due to absorption process.Nevertheless,in high concentrations,nanoparticles removed the surfactant from aqueous phase resulting in no free surfactant available in the bulk.Therefore,surfactant effectiveness in reducing IFT and alteration wettability decreased,and as a consequence,oil recovery efficiency dropped compared to lower nanoparticles’concentrations.Moreover,the results of sessile drop experiments and wettability measurements revealed that coating with either the surfactants or the nanoparticles could partially alter the wettability of surface to water-wet,while coating with the surfactants along with the nanoparticles could make a strongly water-wet surface.Seemingly,investigating the microscopic images of pores and throats showed a strong water-wet condition when the surfactant along with the nanoparticles was used.In addition,the results of flooding tests demonstrated that adding the nanoparticles to surfactant solution could increase the ultimate oil recovery significantly.Moreover,microscopic images confirmed that adding the nanoparticles to the surfactant solution can lead to forming oil-in-water and water-in-oil micro-emulsions due to ultra-low IFT.Obviously,this can result in improving the effectiveness of injection fluid to influence a wider range of porous media.