POLYMER-BASED CENTRALIZER FOR DOWNHOLE DRILLING APPARATUS
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.
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.