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:
Feb. 15, 1994
Filed:
Nov. 16, 1992
Harry L Chang, Dallas, TX (US);
Atlantic Richfield Company, Los Angeles, CA (US);
Abstract
A method for increasing oil recovery from a subterranean formation, the method consisting essentially of injecting a slug of water equal in volume to at least about 20% of the hydrocarbon pore volume of the formation into the formation, thereafter injecting a slug of solvent, the solvent consisting of materials selected from the group consisting of carbon dioxide, nitrogen, methane, hydrocarbons containing from 2 to about 5 carbon atoms and mixtures thereof, into the formation in a volume equal to from about 2% to about 10% of the initial hydrocarbon pore volume of the formation, thereafter injecting a water slug in an volume equal to from about 0.5 to about 3.0 times the volume of the preceding solvent slug, and repeating the solvent and water injection steps for a plurality of cycles with the amount of hydrocarbons containing from 2 to about 5 carbon atoms in the solvent decreasing from about 90 to about 100 mole percent in the initial solvent to about 30 mole percent in the final solvent and with the volume of solvent in each slug after the first being from about 0.5% to about 2.0% of the initial hydrocarbon pore volume of the formation, and injecting after the last solvent slug, a slug of water equal in volume to at least about 20% of the initial hydrocarbon pore volume of the formation.