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. 23, 1994
Filed:
Nov. 12, 1993
Applicant:
Inventors:
Larry S Eoff, Duncan, OK (US);
Bill W Loughridge, Duncan, OK (US);
Assignee:
Halliburton Company, Duncan, OK (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
166293 ; 106725 ; 106727 ; 106808 ; 106809 ; 523130 ;
Abstract
A method of cementing a wellbore which penetrates a subsurface gas-containing formation is provided whereby gas migration is reduced. The method features the use of an additive consisting of a tannin backbone having grafted thereto at least two different vinylamide derivatives. The additive causes the cement slurry employed in the method to exhibit a Zero Gel Time of greater than about one hour, a Transition Time of less than about one hour and controls fluid loss from the slurry.