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:
Jun. 09, 1987
Filed:
Jul. 12, 1985
Applicant:
Inventors:
David L Connell, Leeds, GB;
Anthony J Gradwell, Leeds, GB;
Assignee:
Sandoz Ltd., Basel, CH;
Primary Examiner:
Int. Cl.
CPC ...
C09K / ;
U.S. Cl.
CPC ...
252-8515 ; 166282 ; 166283 ; 175 65 ; 175 72 ; 252-8551 ; 523130 ; 526312 ;
Abstract
Fluid loss control additives for oil-based well-working fluids comprise a solubilized lignite derivative and an oil-swellable or oil-soluble polymer. The solubilized lignite derivative may be oil-solubilized (e.g. a lignite/amine complex) or water-solubilized (e.g. causticized lignite) and may be incorporated in a polymer matrix or added to a dispersion of a polymer in an aqueous medium.