Stabilization of Nanometal Catalysts and Their Interaction with Oleic Phase in Porous Media during Enhanced Oil Recovery

Two aspects of nanonickel particle injection into porous media were studied: stabilization and transportation. Three different surfactants [sodium dodecylbenzenesulfonate (SDBS), cetyltrimethylammonium bromide (CTAB), and Tergitol Np-9] and xanthan gum polymer were tested for stabilization of the nanoparticles. In the analysis of these tests, zeta-potential, size distribution measurements, and sedimentation photographs were used. The observations were analyzed using the classical DLVO (Derjaguin, Landau, Verwey, and Overbeek) theory. Only xanthan gum polymer could stabilize the particles for a sufficient time, which is required to transport into the oil reservoir. The interaction of the nanoparticles, stabilized in xanthan gum solution, with the oil phase was studied by visualization experiments. It was observed that the transfer of particles to oil water interfaces requires modification of the surface charges of the oil phase. This was achieved by CTAB surfactant. The ionic interactions of the polymer and the surfactant and the presence of oil phase were found to be of utmost importance in this process. The micromodel visualization experiments were also conducted to study the interactions between the injected chemicals with oil and rock matrix. These experiments showed that, when injected with the proposed method, the nickel particles moved to the oil water interface or attached to the matrix without agglomeration. The distribution of the particles depends on the heterogeneity of the medium and the injection rate.