The Role of Asphaltene in Wettability Reversal

Abstract Wettability is an important factor in a number of petroleum production processes. Asphaltene deposition can have a strong role in wettability reversal. Among many factors, the high molecular weight, polar fraction of crude oils, including the asphaltenes, are considered to be the primary wettability altering agents. Understanding the role of asphaltene in wettability of reservoir fluids on solid surfaces and its reversal will help us plan for more efficient oil recovery processes. It will also establish the role of asphaltene deposition in the production operation of asphaltic crudes including heavy petroleum crudes. In this paper the groundwork for the study of the complex role of asphaltene and its deposition in altering the wettability of reservoir fluids on solid surfaces is presented. A number of experimental observations in support of the strong role of asphaltene in altering the interfacial tensions and wettability is reported. A new molecular theory for prediction of wettability and its reversal is also introduced.