Surface Treated Nanoparticles as Foam Stabilizing Agent in Enhanced Water-Alternating-Gas (EWAG) Application

Abstract

Abstract Foam-assisted water-alternating-gas (FAWAG) or Enhanced WAG (EWAG) has been identified as one of the methods to improve WAG performance by reducing mobility of its gas phase through foam introduction, hence improving overall sweep efficiency. Foam generation in porous media has been thoroughly studied at fundamental level, and a few mechanisms being proposed (Falls et. al. 1998, Boos et. al. 2012). Ability to sustain and propagate foam in porous media such as reservoir rock is still a subject of investigation. Literature suggested the addition of nanoparticles into foaming surfactant formulation can potentially improve foam performance in stability and assist propagation in porous media. Silica dioxide (SiO2) has been the commonly used nanoparticle for oil and gas application, including for FAWAG application (Agista et. al. 2018). It is not difficult to understand silica oxide selection for two main reasons. First, for a sandstone reservoir, silica makes up majority of quartz in rock mineralogy. Second, it is relatively cheaper as compared to the other nanoparticles. The study objectives can be summarized in two parts. Firstly, to test the stability of nanoparticle-foams in relation to its hybrid chemical formulation. Secondly, to validate nanoparticles as foam phase stabilizer during foam propagation in porous media. The study utilized in-house designed and manufactured surface treated silica oxide nanoparticles and in-house fabricated long core core holder equipment. It was observed that the introduction of nanoparticles can assist foam performance and propagation in porous media.