| 摘要 |
The addition of vaporized solvent to injected steam in a fracture-assisted steamflood process provides surprisingly significant enhancement of the process as compared to both the basic fracture-assisted steamflood process of the Britton et al. U.S. Pat. No. 4,265,310 patent and to a conventional matrix drive type steamflood process utilizing solvent. Much lower solvent losses to the formation are observed than are generally provided by conventinal matrix drive type steamflood processes utilizing solvent. Dramatically different effects of the addition of heat-scavenging water follow-up after the steam injection phase are observed as compared to a conventional process utilizing solvent. Directly opposite effects are observed from changes in solvent composition as compared to conventional matrix drive type steamflood processes utilizing steam; for the present invention SOR is decreased by going to lighter solvents, whereas with a conventional process, lighter solvents increase the SOR. Furthermore, the solvent enhanced fracture-assisted steamflood process provides significantly lower overall SOR and significantly higher percentages of recovery of original oil in place, as compared to a conventional steamflood process utilizing solvent.
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