Improvement of Heavy Oil Recovery in the VAPEX Process using Montmorillonite NanoclaysK. Pourabdollah, A. Zarringhalam Moghaddam, R. Kharrat and B. MokhtariOil Gas Sci. Technol. – Rev. IFP Energies nouvelles, 66 6 (2011) 1005-1016DOI: https://doi.org/10.2516/ogst/2011109