Patent ID: 11312895

Abstract:
Surfactants are imbibed into Halloysite nanotubes (HNT) and the imbibed nanotubes are coated with wax on the nanotube outer surface. The wax layer prevents the surfactant from being disgorged from the HNT lumen until a triggering condition exists. Triggering conditions include contact with oil, which dissolves the wax; or exposure to temperatures above a melt transition of the wax, which causes the wax to melt. Upon exposure to a triggering condition, at least some of the imbibed surfactants are disgorged from the HNT and into the surrounding environment. The disgorged surfactants provide a conventional effect of reducing interfacial tension and changing reservoir rock wettability to enhance oil recovery. A range of surfactants and waxes are usefully employed in the compositions and methods described herein.