摘要
This study was conducted to investigate the phenomenon of oil removal from inside pores using a self-designed microfluidic test kit.An artificial micromodel chip as a representation of porous rocks has been created with a uniform pore structure design and made of PMMA(Polymethyl Methacrylate)material.The micromodel chip has a porosity of 27.8%as well as a permeability of 2.7 Darcy.By using the microfluidic test kit,this study has investigated how low salinity water(LSW)injection with MgCl_(2)divalent ions and the addition of anionic surfactant,linear alkylbenzene sulfonate mixed with nonionic surfactants,nonylphenol ethoxylate(NP-10)affects to oil recovery.The injection of LSW and surfactant solution was carried out with different injection stages,injection rates and surfactant solutions con-centrations.Visual images during the injection process are recorded for analysis,which is the advantage of dynamic testing using this microfluidic test kit over conventional coreflooding.From this study,it is indicated that the selection of ions contained in LSW affects the success of LSW injection.Reducing the surfactant injection rate from 50 mL/min to 20 mL/min can increase the oil recovery from 1.27%to 4.29%.Oil recovery was also higher on surfactant injection which resulted in lower interfacial tension of the system based on the calculation of interfacial tension obtained from the Chun-Huh and Ghosh equations from the Winsor test.From all injection scenarios carried out in this study,the highest increase in oil recovery of 26.87%OOIP was obtained by injecting surfactant solutions directly in the secondary stage without prior LSW injection.
