Abstract: The invention is directed to methods for improving the recovery of oil from subterranean geological formations, such as unconventional reservoirs. The invention is also directed to methods for evaluating the efficiency of inject-soak-produce gas injection methods for oil recovery in unconventional reservoirs. In one embodiment, a method for evaluating the efficiency of oil recovery from an unconventional reservoir rock sample includes characterizing the rock sample by imaging the rock sample using a nano-CT scanner and/or scanning electron microscopy (SEM); cleaning the rock sample by flowing solvent through it; saturating the rock sample with crude oil; and establishing initial water saturation in the rock sample.

Abstract: Embodiments of the present disclosure generally relate to methods and formulations for enhanced oil recovery. In an embodiment, a method for treating oil-containing porous media for oil recovery includes introducing oil-containing porous media with a surfactant formulation described herein. Methods can be utilized for, e.g., wettability reversal or oil recovery. Surfactant formulations are also described.

Abstract: Methods for evaluating an optimal surfactant structure for oil recovery by systematically evaluating surfactants' phase behavior, cloud point, dynamic interfacial tension, dynamic contact angle, and spontaneous and forced imbibition. In one embodiment, a method for determining an optimal surfactant structure for oil recovery includes the steps of evaluating a surfactant's phase behavior, evaluating the surfactant's solubility, evaluating the surfactant's dynamic interfacial tension in a porous rock sample, evaluating the surfactant's static and dynamic contact angles in the porous rock sample, evaluating the surfactant's spontaneous imbibition in the porous rock sample, and evaluating the surfactant's forced imbibition in the porous rock sample. In one example, the surfactant comprises a polyoxyethylenated (POE) straight-chain alcohol.

Abstract: The present invention relates to methods for evaluating an optimal surfactant structure for oil recovery by systematically evaluating surfactants' phase behavior, cloud point, dynamic interfacial tension, dynamic contact angle, and spontaneous and forced imbibition.

Abstract: Methods for determining an optimal surfactant structure for oil recovery are described. These methods systematically evaluate surfactants' phase behavior at ambient and at reservoir conditions; cloud point from ambient to reservoir conditions; dynamic interfacial tension at ambient and at reservoir conditions, including crude oil bubble images and fitting drop profiles; static contact angles at ambient conditions and dynamic contact angles at reservoir conditions; spontaneous imbibition at ambient conditions; and forced imbibition at reservoir conditions.

Abstract: Methods for determining an optimal surfactant structure for oil recovery are described. These methods systematically evaluate surfactants' phase behavior at ambient and at reservoir conditions; cloud point from ambient to reservoir conditions; dynamic interfacial tension at ambient and at reservoir conditions, including crude oil bubble images and fitting drop profiles; static contact angles at ambient conditions and dynamic contact angles at reservoir conditions; spontaneous imbibition at ambient conditions; and forced imbibition at reservoir conditions.