George Dee Robbins

US Patent:

59379480, Aug 17, 1999

Filed:

Jan 15, 1998

Appl. No.:

9/007634

Inventors:

George Dee Robbins - Youngsville LA

International Classification:

E21B 1916
E21B 1710

US Classification:

166380

Abstract:

An integrally formed, solid casing centralizer for centering casing strings in oil and gas wells. The casing centralizer includes a central body having a bore adapted to closely engage a casing string and a plurality of integral blades radiating outwardly from the central body. The centralizer is formed by heating a billet of suitable metal to a temperature sufficient to render the billet malleable for extrusion yet which is substantially below a melting temperature of the billet, forcing the metal through a die, thereby forming a workpiece having a profile suitable to form a desired cross-sectional shape of a casing centralizer; cooling the extruded workpiece, and cutting the cooled, extruded workpiece into sections, each section having a length sufficient to form a casing centralizer. Each end of each blade may be bevelled to ease passage of the centralizer into the wellbore, and lock screws may be provided in threaded holes penetrating the central body and blades to fix the centralizers at desired locations on a casing string. The present invention results in an extruded solid casing centralizer substantially free of gas inclusions in the metal, resulting in high strength with minimum dimensions and thereby retaining maximum annular flow area.