Centralisation system

Abstract

The present invention is directed to a tubular centralization system for completing oil, gas, geothermal and other types of wells where the temperatures may be high or the side loads are high, or both. A centralizer has a ring-shaped main body having an inner surface and an outer surface, with a central axis of rotation that passes through the open or hollow centre of the ring from a first open end to a second open end. A plurality of elongate blades extend from the outer surface of the body with each blade forming a wave form with at least two peaks and troughs along the length of the blade.

1 .- 14 . (canceled) 
     
     
         15 . A centralizer for well bore holes, comprising a ring-shaped main body having an inner surface and an outer surface, with a central axis of rotation that passes through the open or hollow centre of the ring from a first open end to a second open end, and a plurality of elongate blades extending from the outer surface, each blade forming a wave form with at least two peaks and troughs along the length of the blade. 
     
     
         16 . A centralizer as claimed in  claim 15  wherein the blades are overall aligned with the axis of rotation. 
     
     
         17 . A centralizer as claimed in  claim 15  wherein the blades are helically spiralled around the centralizer. 
     
     
         18 . A centralizer as claimed in  claim 15  wherein the wave form is sinusoidal. 
     
     
         19 . A centralizer as claimed in  claim 15  wherein each blade is formed from a web that extends radially outwards from the main body of the centralizer, and a flange that extends perpendicularly outward from each side of the outer end of the web across the top of the web. 
     
     
         20 . A centralizer as claimed in  claim 19  wherein the web has the form of a wave and the flange is straight-sided. 
     
     
         21 . A centralizer as claimed in  claim 19  wherein both the web and the flange have the form of a wave. 
     
     
         22 . A centralizer as claimed in  claim 15  wherein each of the blades runs along the outer surface of the central body of the centralizer from close to or at the first end, to close to or at the second end. 
     
     
         23 . A centralizer as claimed in  claim 22  wherein the blades curve concavely inwards towards the outer surface of the main body and merge with the surface close to or at the open end. 
     
     
         24 . A centralizer as claimed in  claim 23  wherein the merge occurs substantially where the wave is axially aligned with the central axis of the centralizer. 
     
     
         25 - 27 . (canceled) 
     
     
         28 . A centralizer as claimed in  claim 15  wherein there are at least four and preferably twelve blades spaced equidistant from one another around the outer surface of the centralizer. 
     
     
         29 . A centralizer as claimed in  claim 15  wherein the centralizer has a flush mounted grease nipple. 
     
     
         30 - 54 . (canceled)