Method and apparatus for stimulating heavy oil production

摘要

This invention relates to a process for the recovery of hydrocarbons from a hydrocarbon bearing formation having an extraction chamber where the extraction chamber has an extraction surface. The process has the steps of heating a solvent, such as propane, and then placing the solvent into the extraction chamber at a temperature and a pressure sufficient for the solvent to be in a vapor state in said chamber and to condense on said extraction surface. The next step is to produce a liquid blend of solvent and heavy oil and then to separate the solvent from said heavy oil. Then the solvent is purified, before being re-injected into the formation again. The purification step removes less condensable fractions from the solvent to ensure a purity that is high enough to support continued heat transfer at extraction conditions. The pressure and temperature are set to levels to cause less volatile fractions to drain away with the liquid bitumen and solvent blend that is produced, thus mitigating heat transfer poisoning.