Alteration of Reservoir Wettability Due to Asphaltene Deposition in Rhourd-Nouss Sud Est Field, Algeria

Abstract Wettability is an important factor in a number of petroleum production processes including secondary recovery and tertiary recovery operations. In fact these processes in the later life of the reservoir are more or less controlled by the wetting properties of the rock and fluids present in it. The role of Asphaltene deposition on the wettability is investigated in this research work. It has been observed that the Asphaltene deposition has a strong role in wettability reversal. Among many factors, the high molecular weight with, polar fraction of crude oils, including the asphaltenes, are considered to be the primary wettability altering agents. Considering the complexity of reservoir rocks and crud oils, each reservoir system is a specific case and its behavior can only be confirmed through experimental work. In this paper the role of asphaltene and its deposition in altering the reservoir wettability of Rhourd-Nouss Sud Est (RNSE Algeria) field is presented. It was found that the samples of RNSE are of intermediate wettability and are very close to neutral wettability. At higher concentrations of asphaltenes in the crude oil the rocks have greater tendency to become neutral-wet systems.