Solvent separation in a solvent-dominated recovery process

摘要

In solvent-dominated recovery processes for recovering In situ oil, including bitumen, the produced fluid stream includes oil and solvent. The solvent is preferably recovered and reinjected into the reservoir. In previously described methods, solvent is removed from the oil/solvent mixture. In the present method, the oil/solvent mixture is first separated into a heavier stream and a lighter stream from which solvent is independently removed.

主权项

1. A method of producing hydrocarbons from an underground reservoir, the method comprising:
(a) injecting a viscosity-reducing solvent into the reservoir; (b) producing a fluid stream from the reservoir comprising two liquid hydrocarbon phases; (c) at least partially separating the two liquid hydrocarbon phases into a lighter stream and a heavier stream; (d) at least partially recovering the viscosity-reducing solvent from each of the lighter stream and the heavier stream to form a lighter solvent-stripped liquid stream and a heavier solvent-stripped liquid stream; and (e) re-injecting at least a portion of the viscosity-reducing solvent recovered from one or both of the lighter and heavier streams, into the reservoir.