Curved structural pipe shoe

Abstract

A system for orienting a drill bit prior to drilling into a formation, comprising a first pipe having an inside pipe diameter, the first pipe being positioned in a hole in the formation, and a curved shoe positioned in said first pipe at a desired orientation, said curved shoe including a funnel portion having an outlet that is off-center within the first pipe and a guide portion having a guide inlet in communication with the funnel outlet and an guide outlet that is off-center within the first pipe, the guide outlet occupying a different azimuthal position within the first pipe than is occupied by the guide inlet.

1 . A method for orienting a drill bit prior to drilling into a formation, comprising:
 a) positioning in the formation a first pipe having an inside pipe diameter and a a curved shoe positioned in the first pipe at a desired azimuthal orientation, said curved shoe including:
 a funnel portion having an outlet that is off-center at a first azimuthal position within the first pipe; and 
 a guide portion having a guide inlet in communication with the funnel outlet and an guide outlet that is off-center at a second azimuthal position within the first pipe, the second azimuthal position being different than the first azimuthal position; 
   b) inserting a drill bit and drill string through the curved shoe such that the bit extends from the curved shoe at an angle with respect to said first pipe.   
     
     
         2 . The method according to  claim 1  wherein step a) includes cementing the first pipe into the formation. 
     
     
         2 . The method according to  claim 2  wherein step a) includes cementing the curved shoe into the first pipe. 
     
     
         3 . The method according to  claim 1  wherein the angle in step b) is at least 3 degrees. 
     
     
         4 . The method according to  claim 1  wherein the azimuthal position of the guide outlet within the first pipe is diametrically opposite the azimuthal position of the guide inlet within the first pipe. 
     
     
         5 . The method according to  claim 1  wherein the guide portion includes a float valve therein. 
     
     
         6 . A system for orienting a drill bit prior to drilling into a formation, comprising:
 a first pipe having an inside pipe diameter, said first pipe being positioned in a hole in the formation; and   a curved shoe positioned in said first pipe at a desired orientation, said curved shoe including:
 a funnel portion having an outlet that is off-center at a first azimuthal orientation within the first pipe; and 
 a guide portion having a guide inlet in communication with the funnel outlet and an guide outlet that is off-center at a second azimuthal orientation within the first pipe, the guide outlet occupying a different azimuthal position within the first pipe than is occupied by the guide inlet. 
   
     
     
         7 . The system according to  claim 6  wherein the diameter of the guide inlet is less than half the inside pipe diameter. 
     
     
         8 . The system according to  claim 6  wherein the guide portion is configured such that the axis of its outlet defines an angle of between 2 and 10 degrees with the axis of the first pipe. 
     
     
         9 . The system according to  claim 6  wherein the guide portion is configured such that the axis of its outlet defines an angle of between 3 and 7 degrees with the axis of the first pipe. 
     
     
         10 . The system according to  claim 6  wherein the azimuthal position of the guide outlet within the first pipe is diametrically opposite the azimuthal position of the guide inlet within the first pipe. 
     
     
         11 . The system according to  claim 6 , further including a float valve within the guide portion.