from about 0 1 days to about 1000 days alternatively from about 1 days to about 100 days alternatively from about 1 day to about 10 days the viscosity of the oil may be reduced by an amount ranging from about 10 to about 80 alternatively by an amount ranging from about 25 to about 75 alternatively by an amount ranging from about 30 to about 50 embodiments of the above disclosed method may be used in conjunction with other heavy oil recovery methods including without limitation steam flood water flood solvent flood steam stimulation or combinations thereof heavy oil was reacted with ruthenium colloidal dispersion in the presence of hydrogen to make the colloidal dispersion the ruthenium nanoparticles were dispersed in an ionic liquid after pressurizing to 60 bar with hydrogen the solution of ruthenium and ionic liquid was stirred for 2 hours at 60 u00b0 c the different ionic liquids 1 butyl 3 methylimidazolium bmim acetate and 1 ethyl 3 methylimidazolium emim acetate tested are shown along with their viscosities before and after reaction in table 1 below the ruthenium nanoparticles were reacted with heavy oil samples at 120 u00b0 c 150 bar h 2 and 16 h the heavy oil samples were actual samples taken from a test well results of the viscosity of heavy oil after reaction with ruthenium stabilized.