Polymer-based centralizer for downhole drilling apparatus

Abstract

The invention provides a centralizer for use with downhole operations. The centralizer is formed of a hollow, cylindrical body having an exposed outer surface and formed of a non-metallic material, a plurality of non-metallic blades protruding from the outer surface of the cylindrical body, and a plurality of wear buttons positioned on each of the plurality of blades, each of the wear buttons having a surface designed to reduce grabbing or sticking and wear of the hollow cylindrical body, such as a smooth, oval surface.

What is claimed is: 
     
         1 . A centralizer for use with downhole apparatus, comprising:
 a hollow, cylindrical body having an exposed outer surface and formed of a non-metallic material;   a plurality of blades formed of non-metallic material, protruding from the outer surface of the hollow cylindrical body; and   a plurality of wear buttons positioned on each one of the plurality of blades, each of the wear buttons having a surface designed to reduce friction.   
     
     
         2 . The centralizer of  claim 1 , wherein the non-metallic material is selected from the group consisting of polymers, resins, and composites comprising non-metallic materials. 
     
     
         3 . The centralizer of  claim 2 , wherein the polymers include phenolic-based compounds and nylon-based compounds. 
     
     
         4 . The centralizer of  claim 2 , wherein the composites include filament wound composites of carbon fiber or fiberglass. 
     
     
         5 . The centralizer of  claim 1 , wherein the surface of each of the plurality of wear buttons is an exposed, smooth surface. 
     
     
         6 . The centralizer of  claim 1 , wherein the exposed, smooth surface of each of the plurality of wear buttons has a curved face. 
     
     
         7 . The centralizer of  claim 1 , wherein each of the plurality of blades includes at least two of the wear buttons. 
     
     
         8 . The centralizer of  claim 1 , wherein each of the plurality of blades includes at least four of the wear buttons, each of the wear buttons being spaced equally apart along a length of each of the plurality of blades. 
     
     
         9 . The centralizer of  claim 1 , wherein each of the plurality of wear buttons has a substantially cylindrical, spherical, or ovular shape. 
     
     
         10 . The centralizer of  claim 1 , wherein the plurality of wear buttons are formed of polytetrafluoroethylene, polyetheretherketone, ceramic, carbide, zirconia, or combinations thereof. 
     
     
         11 . The centralizer of  claim 1 , wherein the plurality of wear buttons function to reduce abrasive forces exerted upon the centralizer when in use. 
     
     
         12 . The centralizer of  claim 1 , wherein the plurality of wear buttons are formed of two or more different materials. 
     
     
         13 . A centralizer for use with downhole apparatus, comprising:
 a hollow, cylindrical body having an exposed outer surface and formed of a non-metallic composite material;   a plurality of non-metallic blades protruding from the outer surface of the cylindrical body and oriented in a parallel or spiral arrangement; and   a plurality of ceramic wear buttons positioned on each of the plurality of blades, each of the wear buttons having an exposed and smooth curved surface.   
     
     
         14 . A centralizer for use with downhole apparatus, comprising:
 a hollow, cylindrical body having an exposed outer surface and formed of a non-metallic material;   a plurality of blades protruding from the outer surface of the hollow cylindrical body; and   a plurality of wear buttons protruding from each one of the plurality of blades, each of the wear buttons having a surface designed to reduce friction,   wherein the plurality of blades and plurality of wear buttons are formed of the same non-metallic material.   
     
     
         15 . The centralizer of  claim 14 , wherein the plurality of wear buttons are formed integrally with each of the plurality of blades.