Crude oil is a complex fluid containing various components with widely different chemical properties. When it comes in contact with water, its polar components adsorb at the oil/water interface, reducing the interfacial tension and eventually developing viscoelastic films. The interfacial films impact emulsion stability and, in some cases, adhere to the oil-bearing reservoirs rocks, altering their wettability and thus hindering oil mobilization. Despite the substantial research conducted in this area, the underlying mechanisms relating the physicochemical properties of the interfacial films to the composition of the bulk phases are still unclear. Here, we investigate the formation of crude oil/water interfacial films. We measure both the time dependent shear and extensional interfacial rheology moduli, and we relate it to the chemical composition of the films. 

To study the rock/fluid interaction, we present experimental verification of a capillarity-driven pore invasion mechanism that can potentially recover bypassed asphaltenic oil from reservoir formations. First, we fabricate mixed-wet capillaries with angular cross-sections inspired by the naturally occurring primary drainage of pore filling brine by invading crude oil. We validate our proposed procedure by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), and contact angle measurements. After employing our novel coating procedure, we experimentally investigate the invasion in mixed-wet square capillaries and compare it with the predictions of dynamic and quasi-static (Mayer-Stowe-Princen (MSP)) meniscus-invasion models dynamic models.