A technique is illustrated which uses a single 3D seismic monitor survey along with multiple seismic attributes in conjuncture with an offset baseline survey to discriminate heated reservoir from unhealed reservoir. 3D seismic monitoring has definitively mapped steam heated regions of the reservoir at two separate geographic locations encompassing more than 150 wells in Cold Lake. Based on these maps infill wells have been drilled into those regions of the reservoir which have remained unhealed after ten years of steam injection.