Abstract: Techniques for recovering hydrocarbons, such as heavy hydrocarbons or bitumen, from a cellar region below a horizontal production well can include providing a cellar well section that extends from the horizontal production well into the cellar region. The horizontal production well can be part of a Steam-Assisted Gravity Drainage (SAGD) in situ recovery system, which forms a hydrocarbon depleted region and a hydrocarbon bearing cellar region. The cellar region includes hydrocarbons that have been pre-heated by SAGD operations. One or more cellar well sections are provided from the SAGD production well to extend into the cellar region, in order to form a branched production well. A pressurizing gas can be injected into the hydrocarbon depleted region from a SAGD injection well, in order to provide sufficient pressure to promote production of pre-heated hydrocarbons from the cellar region through the cellar well section.

Abstract: A method for recovering viscous hydrocarbons from a reservoir in a subterranean formation includes (a) injecting steam into the reservoir. In addition, the method includes (b) injecting a surfactant into the reservoir with the steam during (a). Further, the method includes (c) decreasing the viscosity of the hydrocarbons in the reservoir with thermal energy from the steam. Still further, the method includes (d) emulsifying the hydrocarbons with the surfactant during (b) and (c). Moreover, the method includes (e) mobilizing at least some of the hydrocarbons in the reservoir.

Abstract: A method for mobilizing viscous hydrocarbons in a reservoir includes (a) injecting an aqueous solution into the reservoir with the reservoir at the reservoir ambient temperature. The aqueous solution includes water and a water-soluble chemical agent that is substantially non-decomposable and substantially non-reactive in the reservoir at the reservoir ambient temperature. In addition, the method includes (b) adding thermal energy to the reservoir at any time after (a) to increase the temperature of at least a portion of the reservoir to an elevated temperature greater than the ambient temperature of the reservoir. Further, the method includes (c) in response to the elevated temperature in (b), mobilizing at least a portion of the hydrocarbons in the reservoir by reducing the viscosity of the hydrocarbons and allowing the chemical agent to enhance mobilization of the hydrocarbons.

Abstract: A method for recovering viscous hydrocarbons from a reservoir in a subterranean formation includes (a) injecting steam into the reservoir. In addition, the method includes (b) injecting a thermally activated chemical species into the reservoir with the steam during (a). The thermally activated chemical species decomposes at a temperature between 40° and 200° C. Further, the method includes (c) decreasing the viscosity of the hydrocarbons in the reservoir during (a) and (b). Still further, the method includes (d) mobilizing at least some of the hydrocarbons in the reservoir.

Abstract: Techniques for recovering hydrocarbons, such as heavy hydrocarbons or bitumen, from a cellar region below a horizontal production well can include providing a cellar well section that extends from the horizontal production well into the cellar region. The horizontal production well can be part of a Steam-Assisted Gravity Drainage (SAGD) in situ recovery system, which forms a hydrocarbon depleted region and a hydrocarbon bearing cellar region. The cellar region includes hydrocarbons that have been pre-heated by SAGD operations. One or more cellar well sections are provided from the SAGD production well to extend into the cellar region, in order to form a branched production well. A pressurizing gas can be injected into the hydrocarbon depleted region from a SAGD injection well, in order to provide sufficient pressure to promote production of pre-heated hydrocarbons from the cellar region through the cellar well section.