Carbonated waterflooding for viscous oil recovery using a CO.sub. 2 solubility promoter and demoter

摘要

Viscous oil is recovered from a subterranean, viscous oil- containing formation by injecting a slug of CO.sub.2 carbonated water containing a CO.sub.2 solubility promoter, a slug of a CO.sub.2 solubility demoter, and a water drive to displace the mobilized oil to a production well for recovery.