In situ recovery of hydrocarbons from tar sands
AssigneeThe Ralph M. Parsons Company
InventorCharles B. Barry
Life of this patent
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Abstract
Hydrocarbon products from viscous tar sands are recovered by continuously injecting a hot solvent containing relatively large amounts of aromatics into the formation. Alternatively, steam and solvent are cyclically and continuously injected into the formation to recover the values. The last stimulation is by steam so that solvent is recovered. A third alternative is to continuously inject a mixture of steam and solvent vapors and liquid into the formation. In all cases, the solvent, except perhaps for startup, is produced at the site, as in a conventional topping unit, which alternatively is combined with a conventional visbreaking or reforming unit to increase the volume and/or aromaticity of the solvent produced.
Claims7
In a process for the recovery of hydrocarbons from subterranean deposits of hydrocarbons having high viscosities and including tar sands, oil and tar deposits by injected fluid stimulation of the deposit, the improvement which comprises:
- a. cyclically injecting into the deposit in at least one injection well;
- i. a solvent stimulant of high aromatic content produced from the recovered hydrocarbon, the solvent being introduced at a temperature from about 200.degree. to about 650.degree. F and
- ii. a steam stimulant;
- b. recovering stimulated hydrocarbon from the deposit at at least one product well;
- and
- c. producing solvent from the recovered hydrocarbon in an area proximate the area of hydrocarbon recovery for cyclic injection into the deposit.
Dependencies are inferred from the claim text.