Ionic liquid enhanced surfactant solution for spontaneous imbibition in fractured carbonate reservoirs

A method, comprising:

• introducing an aqueous composition into a carbonaceous hydrocarbon-bearing formation comprising hydrocarbons such that the aqueous composition contacts the carbonaceous hydrocarbon-bearing formation and modifies a wettability value of the carbonaceous hydrocarbon-bearing formation from a first, more oil-wet value to a second, less oil-wet value, thereby releasing at least some of the hydrocarbons from the carbonaceous hydrocarbon-bearing formation into the aqueous composition, where the aqueous composition is a mixture of an ionic liquid and a surfactant in water,
• where there is an interfacial tension value between the aqueous composition and hydrocarbons present in the carbonaceous hydrocarbon-bearing formation,
• where the presence of the ionic liquid in the aqueous composition does not substantially impact the interfacial tension value between the hydrocarbons in the carbonaceous hydrocarbon-bearing formation and the aqueous composition,
• where the ionic liquid has aromatic nitrogenous functionality that is an imidazolium salt selected from the group consisting of 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1,3-dimethylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazoium chloride, and combinations thereof,
• where the combined amount of the ionic liquid and the surfactant is in a range of from 0.05 wt. % to 1 wt. % of the aqueous composition, and
• where the surfactant and the ionic liquid are in a weight ratio to each other in a range of from about 1:3 to about 3:1.