Segmented Downhole Tool

Abstract

A downhole tool includes a plurality of segments positioned on a core member. This construction is particularly suitable for sleeves, stabilizers and drill bit gage pads used in the formation of oil and gas wells. Worn or damaged segments can be replaced without the need for replacing the entire unit. The segments may include spiral vanes for directed fluid upwardly to the well head.

1 . A downhole tool comprising:
 a core member; and   a plurality of separable segments fitted over and secured to the core member.   
     
     
         2 . A down hole tool according to  claim 1  wherein the tool is a stabilizer, and the segments include a plurality of vanes. 
     
     
         3 . A downhole tool according to  claim 1  including an upper and a lower collar on the core member, and the segments are located on the core member between the upper and lower collars. 
     
     
         4 . A downhole tool according to  claim 1  wherein the core member is a hollow tubular member. 
     
     
         5 . A downhole tool according to  claim 1  wherein the core member has an upper threaded portion for connection to a tubular element and has a lower threaded portion for connection to a drill bit or other tool. 
     
     
         6 . A downhole tool according to  claim 1  wherein adjacent segments have cooperating pins and holes to prevent rotation between the segments. 
     
     
         7 . A downhole tool according to  claim 1  wherein each segment has a hole from its exterior surface to its interior surface and a pin positioned within the hole forced up against the core member to prevent rotation of the segment with respect to the core member. 
     
     
         8 . A downhole toll according to  claim 1  including an upper and a lower collar welded to the core member, and the segments are located on the core member between the upper and lower collars. 
     
     
         9 . A method of repairing a worn downhole tool used during the formation of an oil or gas well comprising:
 providing a downhole tool as claimed in  claim 1 ;   withdrawing the tool from the well; and   replacing the worn out segment of the tool with a new segment or modifying blade configuration by changing pitch or blade widths.