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:
Oct. 10, 1989
Filed:
Aug. 14, 1986
Applicant:
Inventors:
Patrick Cros, Melle, FR;
Robert Pipon, Melle, FR;
Assignee:
Rhone-Poulenc Specialites Chimiques, Courbevoie, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07G / ; C08B / ; E21B / ;
U.S. Cl.
CPC ...
536114 ; 536183 ; 536124 ; 166246 ;
Abstract
Novel deacetylated polysaccharide biopolymers having improved viscosity/filtrability/injectability, well adopted for the secondary and tertiary recovery of oil deposits, are conveniently prepared by (i) acidifying an aqueous polysaccharide composition, e.g., a carbohydrate fermentation broth, with nitric acid to a pH of from about 2 to 0.1, (ii) heat-treating said acidified composition at a temperature of from about 50.degree. to 100.degree. C. for from about 5 to 60 minutes, and (iii) cooling said heat-treated composition and adjusting the pH thereof to a value of from about 5 to 7.