Apparatus and method for penetrating cement surrounding a tubular

Abstract

Apparatus and method for penetrating cement ( 300 ) surrounding a tubular ( 200 ) cemented to a formation ( 400 ). The apparatus comprises a bore ( 10 ) through the tubular wall ( 200 ), and an intermediate fluid channel ( 102 ) in an insert ( 100 ) within the bore. An inner sleeve ( 120 ) may be disposed on the interior surface of the tubular wall ( 200 ). The inner sleeve ( 120 ) is movable between a closed position wherein fluid connection between the interior of the tubular and the bore is prevented, and an open position wherein fluid connection between the interior of the tubular and the bore is allowed. An abrasive and/or etching fluid is supplied through the channel ( 102 ) to remove cement and/or the insert ( 100 ) or piston assembly.

1 . Apparatus for penetrating cement ( 300 ) surrounding a tubular ( 200 ) cemented to a formation ( 400 ), the apparatus being characterized by:
 a bore ( 10 ) through the tubular wall ( 200 ), and   an intermediate fluid channel ( 102 ) in an insert ( 100 ) within the bore.   
     
     
         2 . Apparatus according to  claim 1 , further comprising:
 an inner sleeve ( 120 ) disposed on an interior surface of the tubular wall ( 200 ), the inner sleeve being movable between a closed position wherein fluid connection between the interior of the tubular and the bore is prevented, and an open position wherein fluid connection between the interior of the tubular and the bore is allowed.   
     
     
         3 . Apparatus according to  claim 1 , wherein the bore ( 10 ) through the tubular wall ( 200 ) is in a direction perpendicular to the tubular wall ( 200 ). 
     
     
         4 . Apparatus according to  claim 1 , wherein the insert ( 100 ) is a piston assembly disposed in the bore and movable in an axial direction of the bore ( 10 ), the piston assembly comprising a hardened tip ( 105 ) at an outer end and a piston ( 110 ) at an inner end, and the fluid channel ( 102 ) being provided through the piston assembly to the vicinity of the tip ( 105 ). 
     
     
         5 . Apparatus according to  claim 1 , wherein the bore is provided with a removable seal ( 140 ) near an exterior surface of the tubular. 
     
     
         6 . Apparatus according to  claim 1 , wherein the insert ( 100 ) within the bore ( 10 ) is erodible by an abrasive and/or etching fluid. 
     
     
         7 . Apparatus according to  claim 1 , wherein the insert is disposed in a housing ( 101 ) made from a material that is more resistant to abrasion and/or corrosion than the material of the tubular wall ( 200 ). 
     
     
         8 . Apparatus according to  claim 4 , further comprising a substance ( 150 ) capable of swelling when a liquid is added thereto, the swelling substance ( 150 ) being disposed between the piston ( 110 ) and an interior wall ( 103 ), and the interior wall ( 103 ) comprising ports ( 102 ) that are opened or closed by the inner sleeve ( 120 ). 
     
     
         9 . Method for penetrating cement ( 300 ) surrounding a tubular ( 200 ) cemented to a formation ( 400 ), the method being characterized by:
 providing a fluid from an interior of the tubular through an intermediate fluid channel ( 102 ), the fluid being capable of removing cement and/or material from an insert ( 100 ) surrounding the fluid channel.   
     
     
         10 . Method according to  claim 9 , further comprising prior to providing the fluid, providing an inner sleeve ( 120 ) on an interior surface of the tubular wall ( 200 ), and moving the inner sleeve from a closed position wherein fluid connection between the interior of the tubular and the bore is prevented, to an open position wherein fluid connection between the interior of the tubular and the bore is allowed. 
     
     
         11 . Method according to  claim 9 , further comprising the step of forcing a hardened tip ( 105 ) from the interior of the tubular wall ( 200 ) into the cement with sufficient force to cause a groove and/or cracks in the cement before providing the fluid. 
     
     
         12 . Method according to  claim 11 , wherein forcing the hardened tip ( 105 ) into the cementing involves applying hydraulic pressure from the interior of the tubular on a piston ( 110 ) rigidly connected to the tip ( 105 ). 
     
     
         13 . Method according to  claim 11 , wherein forcing the hardened tip into the cementing involves opening a fluid channel from the interior of the tubular to an expandable substance arranged to exert a force on the piston ( 110 ). 
     
     
         14 . Method according to  claim 9 , wherein providing the fluid involves providing an abrasive fluid. 
     
     
         15 . Method according to  claim 9 , wherein providing the fluid involves providing at least one chemical capable of etching cement and/or the material of the insert.