Patent ID: 8056624

Claim:
A method to recover heavy hydrocarbons from an underground reservoir, the method comprising the steps of: a) providing a well, having a first heel and a first toe, located near the top of the reservoir in the oil formation where the oil phase viscosity at the top of the reservoir is lower than the oil phase viscosity deeper in the reservoir and producing reservoir hydrocarbons from the well under cold production conditions (non-thermal); b) at a later time, drilling a lower inclined well in the reservoir at a position where the oil phase viscosity is higher than at the top well, having a second heel and a second toe, that has the second toe relatively close to the first toe of the top well and the second heel deeper in the oil formation below the first heel of the top well, c) injecting injectant into the top well and producing reservoir fluids from the lower inclined well; and d) continuing to inject injectant into the top well and producing reservoir fluids while growing a vapour and mobilized hydrocarbon chamber along the wellpair from the toes to the heels of the wells.