Method for in situ recovery of heavy crude oils and tars by hydrocarbon vapor injection

摘要

The recovery of heavy crude oils and tars from subterranean oil bearing formations is enhanced by the injection of pressurized and heated hydrocarbon vapor into a single well drilled into the formation. Condensation of the hydrocarbon vapor heats the heavy oil and tars entrapped in the formation and dilutes the oil so as to decrease its viscosity and enhance its flow into a lower portion of the well. The oil and solvent collected are removed to the surface by pumping. The preferred hydrocarbon vapor is a low boiling fraction derived by distillation of the oil recovered from the formation, however, some stable externally-produced aromatic hydrocarbon vapors of high solvent power such as benzene or toluene or mixtures thereof may also be used and reclaimed from the oil by distillation.