Study of Diffusivity of Hydrocarbon Solvent in Heavy Oil Saturated Sands Using X-ray Computer-Assisted Tomography
Luo, H. and Kantzas, A.
DOI: 10.2118/2008-143 & ISSN: 00219487
CIM 2008-143 presented at the 59th Annual Technical Meeting of the Petroleum Society held in Calgary, June 17-19, 2008;
Journal of Canadian Petroleum Technology, 50(2), February 2011, Pages 24-34.
Hydrocarbon solvent-assisted processes are thought to be effective EOR technologies for heavy oil and bitumen production. In order to describe those processes quantitatively, the diffusivity of hydrocarbon solvent in oil sands is a crucial required parameter.
Computer Assisted Tomography (CAT), as a non-intrusive method, is a very useful tool to obtain the physical properties of cores (density, porosity, heterogeneities) and the fluids within the cores (saturation or concentration profiles). However, the concentration profiles obtained from diffusion experiments of solvent in oil sands were fluctuating and cannot be used to evaluate the diffusivity. In order to solve the problem, during the data processing of CAT scanning, porosity heterogeneity of porous media and volume changes on mixing are considered to improve the accuracy of concentration profiles dramatically. Subsequently, the diffusivity of hydrocarbon solvent in heavy oil saturated sands is determined based on an updated mathematical model, which considers porosity heterogeneity of porous media in the major diffusion direction and volume changes on mixing. Thus, the impact of porosity heterogeneity of porous media on diffusivity determination of hydrocarbon solvent in heavy oil saturated sands is investigated.