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. 21, 1978
Filed:
May. 09, 1977
Standard Oil Company (Indiana), Chicago, IL (US);
Abstract
A method of selective plugging of undesirable high permeability streaks and channels in oil-bearing reservoirs during high temperature (250.degree. F or higher) injection recovery processes such as steamflooding, underground combustion, flooding of a naturally occurring high-temperature reservoir or the like. Improved sweep efficiency can be effected by injecting a gel-forming solution consisting essentially of sodium or ammonium lignosulfonate and water or brine in the absence of other gelation promoters and then allowing the high temperatures of the underground formation to promote gelation. Optionally, a precooling water injection step can be used prior to placement of the gel-forming solution. This system has the advantage of gel times which are sufficiently long at temperatures in excess of 250.degree. F to permit placement of large volumes characteristic of commercial use. This method is particularly useful in selectively forming firm, strong gels in thief zones for steamflooding recovery operations.