Dual rotary centralizer for a borehole

Abstract

The present invention relates to an apparatus for use in a wellbore, which comprises two rotating bodies 1, 11 and a ring 4 . The said rotating bodies rotate clockwise or anticlockwise on its own axis. Preferably, the present invention provides a dual rotary centralizer with a unique dual rotating design with an advantage of an integral stop. This combination enables a free rotation on the axis of the casing pipe which allows easy casing rotation while the dual rotary centralizer stays in its position onto the casing pipe eliminating altogether the need for stop collars. The clockwise and anticlockwise rotation of two bodies induces extra swirl action.

1 . A dual rotary centralizer comprising:
 a ring ( 4 );   an upper cylindrical body ( 1 ) longitudinally placed on the upper rim of the ring;   a lower cylindrical body longitudinally placed at the bottom rim of the ring; and   an array of equi-angularly-spaced blades ( 10 ) integrally formed with the body of upper and lower cylindrical bodies ( 1 ).   
     
     
         2 . The dual rotary centralizer as claimed in  claim 1 , wherein the said ring comprises of grub screw ( 5 ) and ring thread ( 8 ), placed alternatively on the ring. 
     
     
         3 . The dual rotary centralizer as claimed in  claim 1 , wherein the said ring has uniform diameter with the ring groove  9  on both sides dimensioned to fit around the cylindrical bodies. 
     
     
         4 . The dual rotary centralizer as claimed in  claim 1 , wherein the said array of equi-angularly-spaced blades preferably having upper face ( 3 ) and lower face ( 2 ) preferably, but not limited to, molded on the surface of upper cylindrical body and lower cylindrical body. 
     
     
         5 . The dual rotary centralizer as claimed in  claim 4 , wherein the said blades extend between longitudinally opposite ends of the upper cylindrical body and lower cylindrical body. 
     
     
         6 . The dual rotary centralizer as claimed in  claim 4 , wherein the said blades extend circumferentially around the periphery of the centralizer. 
     
     
         7 . The dual rotary centralizer as claimed in  claim 4 , wherein the said blades are preferably, but not limited to, left oriented, right oriented or straight. 
     
     
         8 . The dual rotary centralizer as claimed in  claim 7 , wherein the left or right oriented blades are molded preferably, at an angle ranging from 15° to 35°. 
     
     
         9 . The dual rotary centralizer as claimed in  claim 7 , wherein the straight blades are molded preferably, at an angle of 90°. 
     
     
         10 . The dual rotary centralizer as substantially as described herein with reference to the drawings and the foregoing description.