A Steam-Assisted Gravity Drainage (SAGD) method for recovering hydrocarbons from a reservoir can include generating steam and CO2 from feedwater, fuel and oxygen; transferring a steam-CO2 mixture comprising at least a portion of the steam and at least a portion of the CO2, to a proximate SAGD injection well; injecting the steam-CO2 mixture into the SAGD injection well; obtaining produced fluids from a SAGD production well underlying the SAGD injection well; transferring the produced fluids for separation proximate to the SAGD production well; separating the produced fluids into a produced gas and a produced emulsion; transferring the produced emulsion for separation proximate to the SAGD production well; separating the produced emulsion to obtain a produced hydrocarbon-containing component and produced water; supplying at least a portion of the produced water as at least part of the feedwater; and supplying the produced hydrocarbon-containing component to a central processing facility.