A number of researchers put on attention on nanoparticles suspension (nanofluids) as part of nanotechnology application in enhanced oil recovery (EOR) nowadays. This experimental study is preliminary stage of nanofluids for EOR project at NTNU. This paper presents the investigation of interfacial tension reduction, nanoparticles retention and permeability impairment in porous media by injecting nanoparticles suspension into glass micromodel. The deposition and pore-blockage of nanoparticles in glass micromodel were investigated and microscopically visualized by taking sequential images. A hydrophilic nanoparticles and synthetic seawater (brine, NaCl 3 wt. %) as base fluid were chosen in this study. The nanofluids were made with various concentration from 0.1 to 1.0 wt. %. The sonicator as liquid homogenization tool was used just before injecting the nanofluids into glass micromodel to avoid agglomeration.
A dynamic interfacial tension (IFT) phenomenon has observed during this experiment. Introducing dispersed nanoparticles in brine has reduced dynamic IFT. It will decrease when increasing nanoparticles concentration. Theoretically, it makes oil easier to move out since the friction force between water-phase and oil-phase will also decrease (Afrapoli, 2010).
Based on microscopic visualization from glass micromodel, it observed nanoparticle has deposited and adsorbed at surface pore network. In permeability measurement, it reduced 41–72% after injected with nanoparticles. Dynamic light scattering analysis is also performed for nanoparticles entrapment analysis. Another nanoparticles which has bigger average size and lower specific surface area, showed similar behavior with previous nanoparticles suspension. However the permeability reduction is less around 17–21% at similar nanofluids concentration.
In conclusion, this phenomenon of nanoparticles transport process possibly occurs due to its deposition on pore surface and blockage in pore throat of glass micromodel. This study provides essential knowledge for us of nanoparticles behavior in pore media before going further experiment stage to as EOR method.