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:
Mar. 21, 1977
Harold J Hill, Houston, TX (US);
Joseph Reisberg, Houston, TX (US);
Fred G Helfferich, Houston, TX (US);
Larry W Lake, Houston, TX (US);
Gary A Pope, Austin, TX (US);
Shell Oil Company, Houston, TX (US);
Abstract
A process for recovering oil by successively injecting at least a chemical slug containing an active aqueous surfactant system or thickened aqueous liquid and an aqueous drive liquid into a reservoir having a significant amount of ion exchange capacity, is improved. The ionic composition of each injected fluid is arranged to provide a ratio, between the concentration of its effectively predominate monovalent cation and the square root of the concentration of its effectively predominate divalent cation, which ratio at least substantially equals such a ratio within the aqueous fluid immediately ahead of the injected fluid.