Experimental study on phase behavior of heavy oil-solvent mixture system

Phase behavior research is of great significance for formulating oilfield development plans. In this paper, an experimental procedure was proposed to investigate the phase behavior of a solvent mixture(5 mol% CO2+45mol% CH4+55 mol% C3H8) with Venezuela Orinoco heavy oil. The measured physical properties of the heavyoil-gaseous solvent system include the bubble point pressure, swelling factor, density and viscosity of the liquid phase as a function of gas mole fraction. The experimental results show that as the gas molar fraction increases from 10% to 30%, the bubble point pressure and swelling factor of the heavy oil-solvent mixture system increase accordingly; as the dissolved gas content in the heavy oil increases, the viscosity and the density of the system is reduced, but the reduction is getting smaller and smaller.