Out of center downhole tool

Abstract

A tubular component configured to be interposed between parts of a drill string used with a cased wellbore. A lobe is supported on and projects from an outer surface of the tubular component. The lobe causes the tubular component to have a cross-sectional profile that is asymmetric relative to an axis of symmetry of the drill string. As the drill string and tubular component rotate, the lobe contacts debris within the wellbore. The lobe also causes the drill string to rotate eccentrically, helping to reduce friction between the drill string and wellbore and dislodge a stuck drill string.

1 . A system, comprising:
 a cased wellbore extending within an underground environment;   an elongate tubular drill string situated, at least in part, within the cased wellbore, the drill string having an axis of symmetry; and   a tubular component interposed between parts of the drill string within the cased wellbore, the component including a section having an enclosed cross-sectional profile that is asymmetric relative to the axis of symmetry.   
     
     
         2 . The system of  claim 1 , in which the tubular component is configured to cause eccentric rotation of the drill string. 
     
     
         3 . The system of  claim 1 , in which the drill string has opposed first and second ends, the first end being situated within the cased wellbore; in which the drill string includes a region situated at least 90 feet from the first end; and in which the tubular component is interposed between parts of the drill string at the region. 
     
     
         4 . The system of  claim 1 , in which the section comprises a lobe projecting from an external surface of the tubular component. 
     
     
         5 . The system of  claim 4 , in which the lobe has a wedge shape. 
     
     
         6 . The system of  claim 4 , in which the tubular component has opposed first and second ends and in which the lobe is positioned at a mid-point between the first and second ends. 
     
     
         7 . The system of  claim 4 , in which a longitudinal axis of the lobe is parallel to a longitudinal axis of the tubular component. 
     
     
         8 . The system of  claim 1 , in which the tubular component comprises an external surface, and in which the tubular component does not comprise any parts that move relative to the external surface. 
     
     
         9 . The system of  claim 1 , in which no ports are formed in the tubular component except for a central fluid passage that interconnects opposed first and second ends of the tubular component. 
     
     
         10 . The system of  claim 1 , in which the tubular component is solid except for a central fluid passage that interconnects opposed first and second ends of the tubular component. 
     
     
         11 . A method of using the system of  claim 1 , the method comprising:
 causing the drill string and interposed tubular component to rotate within the cased wellbore.   
     
     
         12 . A system, comprising:
 an elongate tubular drill string situated, at least in part, within an underground environment, the drill string having an axis of symmetry; and   a plurality of identical tubular components situated in a spaced-apart relationship, each tubular component interposed between parts of the drill string and including a section having an enclosed cross-sectional profile that is asymmetric relative to the axis of symmetry.   
     
     
         13 . The system of  claim 12 , in which the section comprises a lobe attached to an external surface of the tubular component. 
     
     
         14 . The system of  claim 12 , in which the drill string has opposed first and second ends and a first region situated at least 90 feet from the first end of the drill string; and in which a first one of the plurality of identical tubular components is interposed between parts of the drill string at the first region. 
     
     
         15 . The system of  claim 14 , in which the drill string has a second region situated at least 1,000 feet from the first end of the drill string; and in which a second one of the plurality of identical tubular components is interposed between parts of the drill string at the second region. 
     
     
         16 . The system of  claim 15 , in which the drill string has a third region situated at least 2,000 feet from the first end of the drill string; and in which a third one of the plurality of identical tubular components is interposed between parts of the drill string at the third region. 
     
     
         17 . A method of using the system of  claim 12 , the method comprising:
 causing the drill string and interposed tubular components to rotate within the cased wellbore.   
     
     
         18 . The system of  claim 12 , in which the drill string is situated within a cased wellbore. 
     
     
         19 . A method of using a cased wellbore that extends within an underground environment, comprising:
 assembling a drill string having an axis of symmetry such that a tubular component is interposed between parts of the drill string, the component including a section having an enclosed cross-sectional profile that is asymmetric relative to the axis of symmetry;   inserting the drill string and interposed tubular component into the cased wellbore; and   causing the drill string and interposed tubular component to rotate within the cased wellbore.   
     
     
         20 . The method of  claim 19 , in which the drill string has opposed first and second ends and a region that is at least 90 feet from the first end, in which the tubular component is interposed between parts of the drill string at the region. 
     
     
         21 . The method of  claim 19 , further comprising:
 causing the drill string to rotate eccentrically within the cased wellbore.