The objective of this paper is identity and select the most appropriated surfactant systems that favors spontaneous imbibition, changing rock wettability and enhances oil recovery from the shale matrix in unconventional liquid reservoirs (source rock) in Vaca Muerta Formation, East Loma Campana area (black oil window). Several laboratory tests were performed to understand interaction among completion fluids, formation fluids and the mineralogy of the reservoir with surfactant systems. Rock and porous space were characterized through: XRD (X ray diffraction), microscopic study (optical & scanning electron microscopy), RockEval 6 Pyrolysis, NMR (Nuclear Magnetic Resonance) 2 MHz, Gas Filled Porosity. Crude oil sample was characterized by: S.A.R.A. Analysis, density, viscosity, TAN (total acid number), WAT (wax appearance temperature), Pour Point and MW (molecular weight). Three kinds of products were tested: 3 nanoemulsions, 1 microemulsion and 2 micelar solutions. Thermal stability at reservoir conditions (100°C, 96.000 ppm TDS), interfacial tension, contact angle, compatibility with other additives and imbibition test at reservoir temperature were carried out to evaluate the performance and selection of the best chemical product. The product "A" (nanoemulsion) presented the best performance in the stability test at reservoir conditions. This nanoemulsion modified the wettability of reservoir rock and diminished the interfacial tension (oil-water). The imbibition test showed an increment in the oil recovery of twice regarding a common surfactant used in the frac fluid. For the Field Test in the selected location of Vaca Muerta Play, it is recommended to use the Product "A" in a range of concentration between 1,5-2 gpt in the frac fluids