Dual tube drill string components

Abstract

A drill string component having a central axis can comprise an outer tube having a pin end and a box end. The outer tube can define an inner bore. An inner tube can be disposed within the inner bore of the outer tube. The inner tube can defines an inner bore. A plurality of rolling elements can be disposed between the outer tube and the inner tube. The wall thickness of each of the outer tube and the inner tube can be less than ¼ inch.

What is claimed is: 
     
         1 . A drill string component having a central axis, the drill string component comprising:
 an outer tube having a pin end portion and a box end portion, wherein the outer tube defines an inner bore;   an inner tube disposed within the inner bore of the outer tube, wherein the inner tube defines an inner bore; and   a plurality of rolling elements disposed between the outer tube and the inner tube,   wherein the wall thickness of each of the outer tube and the inner tube is less than ¼ inch.   
     
     
         2 . The drill string component of  claim 1 , wherein the wall thickness of each of the outer tube and the inner tube is about 3/16 inch. 
     
     
         3 . The drill string component of  claim 1 , wherein the outer tube portion comprises a first segment and a second segment that is coupled to the first segment, wherein the second segment has an inner surface that defines an inner circumference, wherein inner surface of the second segment defines a plurality of recesses within the inner surface that are spaced about the inner circumference. 
     
     
         4 . The drill string component of  claim 3 , wherein the first segment is a drill rod. 
     
     
         5 . The drill string component of  claim 3 , wherein the second segment is a drill rod. 
     
     
         6 . The drill string component of  claim 3 , wherein the first and second segments have the same length. 
     
     
         7 . The drill string component of  claim 1 , wherein the pin end portion defines at least one male thread that is case-hardened. 
     
     
         8 . The drill string component of  claim 1 , wherein the inner tube has an outer surface that defines a circumferential recess that is configured to receive a portion of each rolling element of the plurality of rolling elements. 
     
     
         9 . The drill string component of  claim 1 , further comprising a centralizing spring that is positioned between and biases against an outer surface of the inner tube and an the inner bore of the outer tube, wherein the centralizing spring is configured to bias the inner tube toward the central axis of the drill string. 
     
     
         10 . The drill string component of  claim 1 , wherein the outer tube has a wall thickness that varies along the central axis of the drill string component. 
     
     
         11 . The drill string component of  claim 1 , wherein the inner tube has a male end portion and a female end portion, wherein the drill string component further comprises at least one sealing element coupled to one of the male end portion or the female end portion. 
     
     
         12 . The drill string component of  claim 11 , wherein the at least one sealing element comprises at least one O-ring. 
     
     
         13 . (canceled) 
     
     
         14 . The drill string component of  claim 11 , wherein the at least one sealing element comprises an annular sleeve. 
     
     
         15 . (canceled) 
     
     
         16 . The drill string component of  claim 1 , wherein the outer tube comprises a plurality of radially extending pads spaced about the circumference of the elongate body. 
     
     
         17 . The drill string component of  claim 16 , wherein the plurality of radially extending pads comprise wear strips. 
     
     
         18 . The drill rod of  claim 1 , wherein the plurality of radially extending pads are arranged in a helical orientation. 
     
     
         19 . (canceled) 
     
     
         20 . The drill rod of  claim 1 , wherein each radially extending pad of the plurality of radially extending pads extends along a respective centerline, wherein the respective centerline intersects a cross-sectional plane that contains the central axis of the drill rod at an acute angle. 
     
     
         21 . The drill rod of  claim 18 , wherein the acute angle is from about 10 degrees to about 30 degrees. 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . A method comprising:
 disassembling a first segment and a segment of an outer tube portion of a drill string component, wherein the drill string component further comprises:
 an inner tube disposed within the inner bore of the outer tube, wherein the inner tube defines an inner bore; and 
 a plurality of rolling elements disposed between the outer tube and the inner tube, 
 wherein the wall thickness of each of the outer tube and the inner tube is less than ¼ inch, 
   using the first segment as a drill rod in a wireline operation.   
     
     
         25 . A drill string comprising:
 a drill bit; and   at least one drill string component coupled to the drill bit, wherein the at least one drill string component comprises at least one drill string component as in  claim 1 .