Concentration-Behavioral, Adsorption, Flooding, Relative Permeability Studies of Polymer Nanocomposite in Two Reservoir Lithologies

Nanomaterials are substances that, because of their size, can easily penetrate small pores and apply their impact. Nanofluids can allow appropriate wettability change in the reservoir rock, therefore, an accurate understanding of the behavioral mechanisms of these nanofluids is important in changing the wettability. This is because if there is no proper understanding of these mechanisms, they may exhibit the opposite behavior and cause damage to the reservoir. In previous research, CuO / TiO2 / PAM nanocomposite was synthesized and mechanistically introduced.

In this study, in continuation of the previous study, the behavioral and mechanism study has been investigated in a more accurate and documented manner, and spectral absorption tests, chemical flooding, and relative permeability diagrams confirm the effectiveness of enhanced oil recovery results of this nanocomposite. In carbonate rocks due to the positive surface charge of the rock and the negative charge of the nanocomposite, adsorption of nanomaterials in a double electrode layer state has been suggested as the dominant mechanism of wettability change. In sandstone rocks due to the charge coincidence of rock surface and nanomaterials which are both negative, the mechanism of disjoining pressure was the dominant mechanism of wettability change. To prove the abovementioned behaviors 200 ppm concentration of nanofluid was analyzed by spectroscopy method of adsorption analysis to validate the attraction forces of the nanocomposite with carbonate rocks and repulsion forces with sandstones.

Dynamic chemical flood tests were performed to confirm the effectiveness of this material in increasing oil production and showed 8.5% and 6.35% increase in oil production for carbonate and sandstone lithologies, respectively. Relative permeability diagrams showed an intersection point in the carbonate system with a 10% increase in water saturation and an intersection point in the sandstone system with a 12% increase in water saturation and the behavioral effect of the material at the studied concentrations.