| CPC C09K 8/584 (2013.01) [C09K 8/588 (2013.01); C09K 8/594 (2013.01); C09K 2208/10 (2013.01)] | 9 Claims |

|
1. A method of controlling mobility of subsurface fluids in a hydrocarbon reservoir by deploying a stabilized subterranean foam, the foam comprising a partially surfactant-decorated nanoparticle, wherein the nanoparticle has a diameter of 10-15 nm and comprises a charged surface characterized by a capacity to bear a charge, and an oppositely-charged ionic surfactant non-covalently decorating only a portion of the charged surface of the nanoparticle, the method comprising:
providing the surfactant and the nanoparticle in the foam in a surfactant concentration and a nanoparticle concentration of greater than 1 weight %, the nanoparticle and the surfactant thereby being provided in a nanoparticle/surfactant concentration ratio in the foam so that the surfactant only partially covers the nanoparticle and so that there is no nanoparticle aggregation, thereby forming a stable suspension of individual partially surface-decorated nanoparticles in the foam; and
providing the partially surfactant-decorated nanoparticle in the foam in a surfactant-decorated nanoparticle concentration selected so as to stabilize the foam in the subterranean presence of a hydrocarbon fluid and/or in the subterranean presence of a saline aqueous fluid, and wherein the nanoparticle/surfactant concentration ratio and the partially surfactant-decorated nanoparticle concentration are selected in combination to increase subterranean stability of the foam in contact with the hydrocarbon fluid and/or the saline aqueous fluid compared to the subterranean stability of a foam having a different nanoparticle/surfactant concentration ratio and/or a different surfactant-decorated nanoparticle concentration; and
deploying the foam in the reservoir so that the stabilized foam contacts the hydrocarbon fluid and/or the saline aqueous fluid to constrain the subterranean movement of the hydrocarbon fluid and/or the saline aqueous fluid.
|