Experimental investigation of asphaltene deposition mechanism during oil flow in core samples

Asphaltene deposition is an issue that has received much attention since it has been shown to be the cause of major production problems in enhanced oil recovery processes. Asphaltenes are heavy oil components which, under certain conditions, precipitate and the solid phase they form may deposit in the porous media of the oil reservoir. All proposed remediation techniques have proven costly and not highly effective, so prevention becomes the only way to counteract the problem. Revelation of the deposition mechanism and determination of the parameters they affect it are necessary in order to devise reliable prevention strategies. In this work, an experimental effort is made to investigate the deposition process in core samples, under simulant and realistic flow conditions. The main experimental tools utilized for this purpose are permeability measurements, analysis of asphaltene concentration, pore structure characterization techniques and Soxhlet extraction for the determination of the deposited asphaltenes. Both dead and reservoir oils are used as well as cores of various permeabilities and pore structure characteristics.