Asphaltenes cake properties
Résumé
One of the major problems encountered during the exploitation of the oil reservoir is the deposition of asphaltene in the porous rock near the wellbore. The crude oil asphaltene considerably reduces the rock permeability and, consequently, the oil production. The aim of this work is to propose a specific test to identify the relevant parameters controlling the damaging potential of asphaltene deposits. Our approach is to avoid the particle/porous media interactions to allow for the characterization of asphaltene-deposit-specific properties. To this end, a filtration process (carried out under static pressure) has been developed. First, experiments conducted on crude oil indicated that two parameters essentially characterize the asphaltene cake: the specific resistance and the delay of the cake growth depending upon the pressure drop. Overall, asphaltene cake shows intrinsic properties (specific resistances and porosities) similar to those of clay or sludge. The absolute porosity of the asphaltene deposit is high, around 88%, while permeabilities are low (10 μDarcy). © 2008 American Chemical Society.