Abstract: Methods and systems for determining a liquid level in a formation between a horizontal segment of an injection wellbore and a horizontal segment of a production wellbore are disclosed. Under shut-in conditions, local temperatures and pressures are determined for each of a plurality of inflow zones along the production wellbore segment. Local profile values are determined based on local shut-in subcool values and local shut-in liquid levels. After flow has resumed, a local liquid level is determined based on the local operating subcool value and the local profile value for that inflow zone. The local profile values may be updated during subsequent shut-ins.

Abstract: Methods and systems for determining a liquid level above a horizontal segment of a wellbore in a formation are disclosed. Local temperatures and pressures are determined for each of a plurality of zones along the wellbore segment. For each zone, a local inflow rate is determined for fluids entering the wellbore from the formation. Based on the local inflow rate, local temperature, and local pressure, a local reservoir pressure is determined, and a local liquid level is determined based on the local reservoir pressure and a pressure associated with an injector wellbore positioned above the horizontal segment.

Abstract: Thermal recovery methods for recovering viscous hydrocarbons from a subterranean formation. The thermal recovery methods include performing a plurality of injection cycles. Each injection cycle in the plurality of injection cycles includes injecting a heated solvent vapor stream into a heated chamber that extends within the subterranean formation and fluidly contacting the viscous hydrocarbons with the heated solvent vapor stream to generate mobilized viscous hydrocarbons. Each injection cycle also includes injecting a steam stream into the heated chamber. The thermal recovery methods further include producing a chamber liquid and/or mobilized viscous hydrocarbons from the subterranean formation.

Abstract: Methods and systems for determining a liquid level above a horizontal segment of a wellbore in a formation are disclosed. Local temperatures and pressures are determined for each of a plurality of zones along the wellbore segment. For each zone, a local inflow rate is determined for fluids entering the wellbore from the formation. Based on the local inflow rate, local temperature, and local pressure, a local reservoir pressure is determined, and a local liquid level is determined based on the local reservoir pressure and a pressure associated with an injector wellbore positioned above the horizontal segment.

Abstract: Methods and systems for determining a liquid level in a formation between a horizontal segment of an injection wellbore and a horizontal segment of a production wellbore are disclosed. Under shut-in conditions, local temperatures and pressures are determined for each of a plurality of inflow zones along the production wellbore segment. Local profile values are determined based on local shut-in subcool values and local shut-in liquid levels. After flow has resumed, a local liquid level is determined based on the local operating subcool value and the local profile value for that inflow zone. The local profile values may be updated during subsequent shut-ins.

Abstract: Thermal recovery methods for recovering viscous hydrocarbons from a subterranean formation. The thermal recovery methods include performing a plurality of injection cycles. Each injection cycle in the plurality of injection cycles includes injecting a heated solvent vapor stream into a heated chamber that extends within the subterranean formation and fluidly contacting the viscous hydrocarbons with the heated solvent vapor stream to generate mobilized viscous hydrocarbons. Each injection cycle also includes injecting a steam stream into the heated chamber. The thermal recovery methods further include producing a chamber liquid and/or mobilized viscous hydrocarbons from the subterranean formation.