Abstract: A method for manufacturing a micromodel with a mixed wettability surface representing a hydrocarbon reservoir is disclosed. The method includes coating a top surface of a hydrophilic substrate with photoresist, covering a top of the photoresist with a photomask, exposing the covered top of the photoresist to UV light that changes a chemical property of a region of the photoresist corresponding to a pattern of the photomask, removing the photomask, removing the region of the photoresist corresponding to the pattern of the photomask based on the chemical property of the region, depositing a hydrophobic thin-film on top of the hydrophilic substrate, and removing a remaining photoresist covered with the thin-film, such that the surface of the hydrophilic substrate is patterned with both a region covered with the hydrophobic thin-film and an uncovered region of the hydrophilic substrate, creating a mixed wettability surface on the hydrophilic substrate that represents the micromodel.