Abstract: Systems and methods for enhancing production of viscous hydrocarbons from a subterranean formation. The methods may include heating a hydrocarbon solvent mixture to generate a vapor stream, injecting the vapor stream into the subterranean formation to generate reduced-viscosity hydrocarbons, and producing the reduced-viscosity hydrocarbons from the subterranean formation. The methods also may include selecting a composition of the hydrocarbon solvent mixture by determining a threshold maximum pressure of the subterranean formation, determining a stream temperature at which the vapor stream is to be injected into the subterranean formation, and selecting the composition of the hydrocarbon solvent mixture based upon the stream temperature and the threshold maximum pressure. The systems may include a hydrocarbon production system that may be configured to perform the methods and/or that may include an injection well, an injectant supply assembly, and a production well.

Abstract: LASER-CSS provides a method to improve cyclic steam-based thermal recovery methods for heavy oils and bitumen. A key improvement over prior art consists of mixing liquid hydrocarbons into the injected steam instead of injecting such hydrocarbon as a separate slug in front of a steam stimulation cycle. The objective of the invention is to enhance field applications of Cyclic Steam Stimulation (CSS) by contacting and mobilizing more of the bitumen with the same amount of steam. This is to help increase the recovery efficiency and ultimate recovery normally achieved with conventional CSS-type process operations. The proposed LASER-CSS method utilizes existing CSS wells at some intermediate stage of reservoir depletion. Liquid hydrocarbons are directly mixed and flashed into the injected steam lines, injected into the CSS wellbores and further transported as vapors to contact heavy oil or bitumen surrounding steamed areas between adjacent wells.

Abstract: LASER-CSS provides a method to improve cyclic steam-based thermal recovery methods for heavy oils and bitumen. A key improvement over prior art consists of mixing liquid hydrocarbons into the injected steam instead of injecting such hydrocarbon as a separate slug in front of a steam stimulation cycle. The objective of the invention is to enhance field applications of Cyclic Steam Stimulation (CSS) by contacting and mobilizing more of the bitumen with the same amount of steam. This is to help increase the recovery efficiency and ultimate recovery normally achieved with conventional CSS-type process operations. The proposed LASER-CSS method utilizes existing CSS wells at some intermediate stage of reservoir depletion. Liquid hydrocarbons are directly mixed and flashed into the injected steam lines, injected into the CSS wellbores and further transported as vapors to contact heavy oil or bitumen surrounding steamed areas between adjacent wells.