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:
Jul. 21, 1992
Filed:
Jan. 17, 1991
Thomas P Lockart, Milan, IT;
Giovanni Burrafato, Milan, IT;
Eniricerche S.p.A., Milan, IT;
AGIP S.p.A., Milan, IT;
Abstract
A method for reducing the permeability of a high-permeability zone in a high-temperature oil reservoir comprises: preparing a gellable polymeric aqueous solution, operating on the surface under controlled conditions; injecting said gellable solution into the oil reservoir through a well; moving the solution through the reservoir until it reaches and substantially fills the high-permeability zone to be treated; and gelling the solution in situ with consequent lowering of the permeability in said high-permeability zone, and is essentially characterized in that the gellable solution is an aqueous solution containing a Cr(III) ion cross-linking agent and a water-soluble organic polymer cross-linkable by the effect of said cross-linking agent, said solution being free or substantially free of ligands for the cross-linking agent and having a pH adjusted to a value within the range of 1.5 to 5.5, depending on the desired gelling time.