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. 26, 1985
Filed:
Mar. 25, 1983
Applicant:
Inventors:
David L Connell, Leeds, GB;
Jacqueline A Coates, Leeds, GB;
Assignee:
Sandoz Ltd., Basel, CH;
Primary Examiner:
Int. Cl.
CPC ...
C09K / ;
U.S. Cl.
CPC ...
252 / ; 252 / ; 252 / ;
Abstract
A fluid loss reducing additive for an oil-based well working fluid is the product of mixing together, in an oil or oil-based fluid, lignite or humic acid with an aliphatic amide or hydroxyamide, or a cyclic derivative thereof, containing no primary or secondary amine or amine salt groups.