Patent ID: 8474531

Claim:
A method comprising: injecting steam into a formation to transfer heat to hydrocarbons in the formation resulting in condensation of the steam; injecting into the formation a solvent for the hydrocarbons and that is liquid under reservoir operating conditions to reduce viscosity of the hydrocarbons upon dissolution with the solvent; injecting into the formation a gas non-condensable under reservoir operating conditions to supplement the steam in maintaining of pressure in the formation as the hydrocarbons and condensate of the steam are being produced, wherein the steam, gas and solvent are injected at a volume fraction of between about 0.10 to 0.30 of steam, between about 0.60 to 0.90 of gas, and between about 0.01 to 0.10 of solvent, wherein the sum of the volume fractions is equal to about 1.0; and producing from the formation the hydrocarbons mobilized by the injecting of the steam and the solvent, wherein the injecting is through a first well with a constant injection pressure maintained for at least 2000 days, the producing is through a second well and the first and second wells are arranged in the formation in a steam assisted gravity drainage well pair orientation.