Torque reducing tubing component

Abstract

A torque reducing tubing component for insertion in a tubing string to be used in a bore hole. Upsets ( 22,30,24,26,28 ) are mounted on the outer surface of the component which reduce the contact between the tubing string and the bore hole wall thereby reducing friction between the tubing string and the bore wall. Grooves ( 46 ) on the upsets act to channel fluid around the upsets creating a fluid bearing film between the contact points of the tubing string and the bore wall. A pressure differential is also created around the upsets serving to attract fluid away from the bore wall so improving the efficiency of the circulation of fluid to the surface. Particular reference is made to a torque reducing tubing component for use in a drill string which improves the efficiency of cuttings removal.

1 . A torque reducing tubing component for insertion in a tubing string, the component comprising a generally tubular body having an inner bore on a longitudinal axis therethrough, first and second ends for connecting the component in the tubing string, and an outer surface including one or more upsets located longitudinally along the body and extending circumferentially around the body, wherein the connections at the first and second ends include joint stand-off upsets.  
     
     
         2 . A component as claimed in  claim 1  wherein the one or more upsets are stand-off upsets.  
     
     
         3 . A component as claimed in  claim 2  wherein the stand-off upsets have an outer diameter greater than an outer diameter of the connections on the first and second ends.  
     
     
         4 . A component as claimed in  claim 2  or  claim 3  wherein a plurality of longitudinally extending arc grooves are located on an outer surface of each stand-off upset.  
     
     
         5 . A component as claimed in  claim 4  wherein the arc grooves spiral around the tubular body in a helical pattern.  
     
     
         6 . A component as claimed in  claim 4  or  claim 5  wherein each arc groove comprises, in the direction of rotation of the tubing string, a first leading edge, a cylindrical bed of the groove and a first trailing edge, wherein each edge connects the cylindrical bed to the outer surface of the stand-off upset at an edge angle.  
     
     
         7 . A component as claimed in  claim 6  wherein the first leading edge includes a positive leading edge angle.  
     
     
         8 . A component as claimed in  claim 6  or  claim 7  wherein the first trailing edge includes a positive leading edge angle.  
     
     
         9 . A component as claimed in  claim 7  or  claim 8  wherein the positive leading edge angle is greater than ninety degrees.  
     
     
         10 . A component as claimed in any preceding claim wherein the one or more upsets are agitator upsets.  
     
     
         11 . A component as claimed in  claim 10  as directly or indirectly dependent on  claim 2  wherein the agitator upsets have an outer diameter smaller than the outer diameter of the stand-off upsets.  
     
     
         12 . A component as claimed in  claim 10  or  claim 11  wherein a plurality of longitudinally extending notch grooves are located on an outer surface of each agitator upset.  
     
     
         13 . A component as claimed in  claim 12  wherein the notch grooves spiral around the tubular body in a helical pattern.  
     
     
         14 . A component as claimed in  claim 12  or  claim 13  wherein each notch groove comprises, in the direction of rotation of the tubing string, a second leading edge, a notch or ‘V’ bed of the groove and a second trailing edge, wherein each edge connects the notch to the outer surface of the agitator upset at an edge angle.  
     
     
         15 . A component as claimed in  claim 14  wherein the second leading edge includes a negative leading edge angle.  
     
     
         16 . A component as claimed in  claim 14  or  claim 15  wherein the second trailing edge includes a positive leading edge angle.  
     
     
         17 . A component as claimed in  claim 15  wherein the negative leading edge angle is less than or equal to ninety degrees.  
     
     
         18 . A component as claimed in any preceding claim wherein the one or more upsets are a combination of stand-off upsets and agitator upsets.  
     
     
         19 . A component as claimed in  claim 18  wherein each stand-off upset is bounded longitudinally by one or more agitator upsets.  
     
     
         20 . A component as claimed in any preceding claim wherein the first and second ends comprise threaded pin and box connections respectively.  
     
     
         21 . A component as claimed in any preceding claim wherein the joint stand-off upsets have a smaller outer diameter than the stand-off upsets.  
     
     
         22 . A component as claimed in any preceding claim wherein the upsets are integral with the tubular body.  
     
     
         23 . A component as claimed in any preceding claim wherein there are five upsets; two joint stand-off upsets located at the first and second ends of the component respectively and three combination upsets located equidistantly along the tubular body between the first and second ends.  
     
     
         24 . A component as claimed in  claim 23  wherein the combination upsets comprise a stand-off upset and two agitator upsets, one positioned on either side of the stand-off upset.  
     
     
         25 . A component as claimed in any preceding claim wherein the component is drill pipe.  
     
     
         26 . A component as claimed in any preceding claim wherein the component is a length of casing.  
     
     
         27 . A method of circulating fluid in a bore hole, the method comprising the steps of: 
 (a) inserting a tubing string into the bore hole, the tubing string including a torque reducing tubing component including joint stand-off upsets at first and second longitudinal ends thereof;    (b) pumping fluid down at least the inner bore of the torque reducing tubing component;    (c) running the tubing string to cause the torque reducing tubing component to hydra-mechanically agitate the fluid; and    (d) returning at least a portion of the fluid to the surface via a path over the outer surface of the torque reducing tubing component.    
     
     
         28 . A method as claimed in  claim 27  wherein the torque reducing tubing component is according to any one of  claims 1  to  26 .  
     
     
         29 . A method as claimed in  claim 27  or  claim 28  wherein the tubing string is a drill string, the fluid is drilling mud and the portion of fluid returned to the surface includes drill cuttings.  
     
     
         30 . A method as claimed in  claim 27  or  claim 28  wherein the tubing string is a casing string and the fluid is cement as would occur when cementing a casing.  
     
     
         31 . A method as claimed in any one of  claims 27  to  30  wherein at step (c) of the method the tubing string is reciprocated within the bore when run.  
     
     
         32 . A method as claimed in any one of  claims 27  to  30  wherein at step (c) of the method the tubing string is rotated in the bore when run.  
     
     
         33 . A torque reducing tubing component for insertion in a casing string, the component comprising a generally tubular body having an inner bore on a longitudinal axis therethrough, first and second ends for connecting the component in the casing string, and an outer surface including one or more upsets, the one or more upsets being located longitudinally along the body and extending circumferentially around the body.  
     
     
         34 . A method of cementing a casing in a borehole, the method comprising the steps of: 
 (a) inserting a casing string into the borehole, the casing string including a torque reducing tubing component;    (b) pumping cement down at least the inner bore of the torque reducing tubing component;    (c) running the casing string to cause the torque reducing tubing component to hydra-mechanically agitate the cement; and    (d) returning at least a portion of the cement to the surface via a path over the outer surface of the torque reducing tubing component.    
     
     
         35 . A method of circulating fluid in a bore hole, the method comprising the steps of: 
 (a) inserting a tubing string into the bore hole, the tubing string including a torque reducing tubing component;    (b) pumping fluid down at least the inner bore of the torque reducing tubing component;    (c) reciprocating the tubing string to cause the torque reducing tubing component to hydra-mechanically agitate the fluid; and    (d) returning at least a portion of the fluid to the surface via a path over the outer surface of the torque reducing tubing component.