Abstract: The present disclosure provides a novel process of using nonionic surfactants in wells at, near, or below their cloud point temperature for increased oil production from reservoir formations. Adjusting the surfactant cloud point temperature to be proximate to the reservoir temperature results in the maximum surface activity of the surfactant, increased adsorption, and better imbibition performance. The nonionic surfactants may be mixed with a solution on surface and then injected into formation brine for spontaneous brine imbibition and crude oil production from oil-wet unconventional reservoir formations.

Abstract: The present disclosure provides a novel process of using nonionic surfactants in wells at, near, or below, their cloud point temperature for increased oil production from reservoir formations. Adjusting the surfactant cloud point temperature to be proximate to the reservoir temperature results in the maximum surface activity of the surfactant, increased adsorption, and better imbibition performance. The nonionic surfactants may be mixed with a solution on surface and then injected into formation brine for spontaneous brine imbibition and crude oil production from oil-wet unconventional reservoir formations. Also disclosed is a surfactant selection process that comprises initial surfactant screening, surfactant persistence tests, and spontaneous imbibition experiments to evaluate the performance of both ionic and nonionic surfactants in altering rock-oil wetting properties and improving oil recovery.

Abstract: The present disclosure provides a novel process of using nonionic surfactants in wells at, near, or below their cloud point temperature for increased oil production from reservoir formations. Adjusting the surfactant cloud point temperature to be proximate to the reservoir temperature results in the maximum surface activity of the surfactant, increased adsorption, and better imbibition performance. The nonionic surfactants may be mixed with a solution on surface and then injected into formation brine for spontaneous brine imbibition and crude oil production from oil-wet unconventional reservoir formations.