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. 19, 1985
Filed:
Sep. 23, 1982
Applicant:
Inventors:
Friedrich Engelhardt, Frankfurt, DE;
Klaus Kuhlein, Kelkheim, DE;
Ulrich Riegel, Frankfurt, DE;
Sigmar von Halasz, Kelkheim, DE;
Jeffery C Dawson, Katy, TX (US);
Anthony R Reed, Houston, TX (US);
Assignees:
Cassella Aktiengesellschaft, Houston, DE;
Dresser Industries, Inc., Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
252 / ; 137 13 ; 166307 ; 524555 ; 524812 ; 5263031 ; 526307 ; 5263071 ; 5263072 ; 5263076 ;
Abstract
New copolymers soluble in water and aqueous acids are disclosed comprising in a statistical distribution in the macromolecule at least 5% by weight of entities containing a formylamino functionality and at least 10% by weight of entities containing an amino carbonyl functionality, which are stable in high concentrations of Bronsted-Lowery acids and can be used as friction reducers in the stimulation of oil or gas wells.