The first objective of this experiment was to improve the stabilization of N2 based foam with nanoparticles as an alternative to typical fracturing fluid, which consists of a gelling agent (HPG - hydroxypropyl guar). The second objective of the project was to investigate the damage caused by nanoparticle-based nitrogen foamed fracturing fluids (F.F) on a reference sandstone, using permeability and porosity tests, optical microscope with a Profilometer, and a scanning electron microscope (SEM). The properties of F.F with two types of SiO2 nanoparticles (hydrophilic fumed silica Areosil 300 and silica sol U-2 obtained by the sol-gel method), such as rheology and core damage, were investigated. The discussion of this research results is based on the stability tests carried out with the use of rheology and the foam half-life, formation damage ratio, and observation of exposed samples using SEM and the Profilometer. The permeability and porosity damage ratios of the damaged core samples were found to decrease when nitrogen foamed fluids were used. These results were confirmed with the Profilometer and SEM images. The experimental data showed that the foam stability increased when silica (SiO2) nanoparticles were added. SiO2 nanoparticle-surfactant-stabilized foam for fracturing is superior to traditional water-based fracturing fluids and causes lower core permeability damage than a traditional F.F.
Keywords: SEM; formation damage; nanoaditives; nitrogen foamed stimulation fluids; reservoir stimulation; rheology.