Abstract: Embodiments of the invention described herein relate to methods and apparatus for recovery of viscous hydrocarbons from subterranean reservoirs. In one embodiment, a method for recovery of hydrocarbons from a subterranean reservoir is provided. The method includes drilling an injector well to be in communication with a reservoir having one or more production wells in communication with the reservoir, installing casing in the injector well, cementing the casing, perforating the casing, positioning a downhole steam generator in the casing, flowing fuel, oxidant and water to the downhole steam generator to intermittently produce a combustion product and/or a vaporization product in the reservoir, flowing injectants to the reservoir, and producing hydrocarbons through the one or more production wells.

Abstract: Embodiments of the invention described herein relate to methods and apparatus for recovery of viscous hydrocarbons from subterranean reservoirs. In one embodiment, a method for recovery of hydrocarbons from a subterranean reservoir is provided. The method includes drilling an injector well to be in communication with a reservoir having one or more production wells in communication with the reservoir, installing casing in the injector well, cementing the casing, perforating the casing, positioning a downhole steam generator in the casing, flowing fuel, oxidant and water to the downhole steam generator to intermittently produce a combustion product and/or a vaporization product in the reservoir, flowing injectants to the reservoir, and producing hydrocarbons through the one or more production wells.

Abstract: A method for producing hydrocarbons from a reservoir is provided. The method includes positioning a burner having a combustion chamber in a first well, supplying a fuel, an oxidant, and one of water or steam from the surface to the burner in the first well, supplying a viscosity-reducing gas from the surface to the reservoir in a conduit separate from the fuel, igniting the fuel and the oxidant in the combustion chamber to generate heat and steam in the burner, injecting the viscosity-reducing gas and steam into the reservoir to reduce the viscosity of and heat hydrocarbons within the reservoir, and recovering hydrocarbons from the reservoir.