Influence of asphaltene inhibitors on asphaltene deposition in the porous media

Abstract

This article deals with organic asphaltene deposition in the reservoir rock, for crude oil having high asphaltene content and high apparent viscosity. The crude oil is characterized using thermal analysis through the thermogravimetric method. Crude oil is blended with heptane and flooded through the formation core at 55°C and 200-1200 psi pressure. With the rise in flow pressure, asphaltene precipitation became more significant with about four hundred times fall in the initial flow rate (flow rate at 200 psi) of crude oil at 1200 psi pressure. Phthalic acid and turpentine oil are used as asphaltene inhibitors for this crude oil. These asphaltene inhibitors are easy to procure, required less dosage for asphaltene dissolution and are relatively less toxic as compared to the other organic solvents used frequently as asphaltene inhibitor in oil industries. The asphaltene inhibitors are injected into the crude oil and flowed through the pores of the core. It is found that the crude oil treated with phthalic acid resulted in 88.23% increment its flow rate as compared to the turpentine oil, suggesting significant organic asphaltene dissolution in the formation rock.