The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 16, 1985
Filed:
Oct. 25, 1983
John L Fitch, Dallas, TX (US);
Lynn D Mullins, De Soto, TX (US);
Mobil Oil Corporation, New York, NY (US);
Abstract
Oil may be recovered from viscous oil-containing formations including tar sand deposits by providing at least one injection well and at least one spaced-apart production well which extend downwardly from the surface and which extend to, and generally horizontally through, the bottom of the oil-containing formation with fluid communication of the horizontally extending portions of each well with the oil-containing formation. A predetermined amount of solvent, preferably 0.05 to 0.30 pore volume is injected into the bottom of the formation via the injection well and fluids including oil are recovered from the formation via the production well. After the desired amount of solvent has been injected into the formation, production is terminated and both the injection well and production well are shut-in to allow the formation to undergo a soak period for a variable time, preferably for a time between 2 to 20 days per foot of vertical thickness of the oil-containing formation. During the soak period, there is substantial mixing of the heavy oil and the solvent in the formation by gravity-driven convection wherein the viscosity of the heavy oil is reduced, thereby making it easier to produce. A driving fluid such as water is then injected into the formation via the injection well and oil of reduced viscosity is produced until there is an unfavorable amount of driving fluid, preferably at least 90 percent.