IMPROVED ISOLATING OF PETROLEUM FROM A STRATA REERVOIR CONTAINING PETROLEUM,BY APPLYING LIGHT HYDROCARBON AND CARBON DIOXIDE

摘要

Recovery of oil from a dipping subterranean oil-bearing reservoir is effected by the injection of a first slug of a light hydrocarbon at a high rate to insure mixing with the reservoir oil adjacent the injection well followed by the injection of a second slug of carbon dioxide at a low rate to form a conditionally miscible transition zone with the altered reservoir oil and thereafter by the injection of a drive agent.