ANTI-RETENTION AGENT IN STEAM-SOLVENT OIL RECOVERY

摘要

The present invention relates to a method for reducing solvent retention in ES-SAGD process so as to increase process economics wherein an anti-retention agent is injected into the reservoir to decrease solvent retention in the reservoir. The anti-retention agent can be made pre-injection or can form in situ, and comprises an agent in which the solvent is readily soluble, such that the solvent partitions into the foam, colloidal dispersion, or gel, and out of the condensed water or steam, and away from the reservoir rock.

主权项

1. A method of producing hydrocarbons from a subterranean formation comprising rock and hydrocarbon that has at least one injection well and at least one producing well in fluid communication with each other, the method comprising:
co-injecting steam and solvent into said injection well; injecting an anti-retention agent comprising a foam or a colloidal dispersion or a gel into said injection well, said anti-retention agent having higher affinity for said solvent than does water or said rock; producing production fluids comprising hydrocarbon, water and solvent from said production well; recovering solvent from said production fluids, wherein more solvent is recovered than would be recovered without the injecting of said anti-retention agent.