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:
Aug. 28, 2001
Filed:
Apr. 07, 1999
Applicant:
Inventors:
Brent Warren, Calgary, CA;
Peter M. van der Horst, Arnhem, NL;
Theodorus A. van't Zelfde, Nijkerk, NL;
Assignee:
Akzo Nobel NV, , NL;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09K 7/02 ;
U.S. Cl.
CPC ...
C09K 7/02 ;
Abstract
Water based drilling fluid compositions which contain at least one viscosity builder and at least one rheological control agent wherein the rheological control agent is an amphoteric polymer, the cationic groups of the amphoteric polymer being quaternary ammonium groups.