Review of wettability characterization for reservoir rocks

Wettability is a key parameter of a reservoir rock system. The understanding of wettability plays a very important role in reservoir behavior and multiphase flow because it has a huge influence on the different petrophysical characteristics of the reservoir such as relative permeability and capillary pressure. Wettability is perhaps among one of the most important and crucial factors that affects the rate of oil recovery and residual oil saturation, and this is very important in the field of enhanced oil recovery. Wettability can be measured qualitatively and quantitatively. Qualitative methods include microscopic visualization of fluid distribution, relative permeability curves and imbibition methods and all these qualititative methods are indirectly inferred from other measurements while on the other hand quantitative methods are the direct measurements and wettability is measured on actual reservoir rock samples using reservoir fluids. The most important of these methods are Contact Angle Method, Amott Method and USBM (US Bureau of Mines) Method. I also discussed a few techniques to alter the wettability like Silanization by treatment with the chemicals of organosilanes compounds and treatment with Chrome complexes. In this study, my focus was on studying the wettability analysis of different naturally occuring reservoir rocks and minerals as well as the wettability analysis for different artificial produced materials like Glass Chips, PDMS (Polydimethylsiloxane) and NOA81(Norland Optical Adhesive 81). And then to compare the wettabily of both of the above mentioned materials in order to study the coherence between them and to select the best artificial material which represents the reservoir for further wettability studies.