Recovery of heavy crude oil or tar sand oil or bitumen from underground formations

Heavy crude oil or tar sand oil or bitumen is recovered from an underground formation containing the same by introducing into said formation via an injection well or conduit a hot alkaline aqueous fluid so as to bring about the movement or migration or stripping of said heavy crude oil or tar sand oil or bitumen from said formation into said hot alkaline aqueous fluid at the interface between said hot alkaline aqueous fluid and said heavy crude oil or tar sand oil or bitumen-containing formation as said hot alkaline aqueous fluid moves along within said formation from said injection well or conduit to a production well or conduit for the recovery of the resulting produced heavy crude oil or tar sand oil or bitumen from said formation as an emulsion via said production well or conduit.