Downhole casing removal tool and method

Abstract

An apparatus for removing a casing from a borehole penetrating a formation in one run of the apparatus in the borehole includes: a carrier conveyed in the borehole; a non-incendiary hole former on the carrier to form a hole in the casing; a fluid discharge device on the carrier to discharge a fluid into the hole to wash an exterior portion of the casing; a casing puller on the carrier and having a casing grip to grip the casing to lift the casing or a portion of the casing out of the borehole; a mechanical cutter on the carrier to cut the casing; and a valve on the carrier to control fluid energy to least one of the non-incendiary hole former, the fluid discharge device, the casing puller, and the mechanical cutter.

1 . An apparatus for removing a casing from a borehole penetrating a formation in one run of the apparatus in the borehole, the apparatus comprising:
 a carrier configured to be conveyed in the borehole;   a non-incendiary hole former disposed on the carrier and configured to form a hole in the casing;   a fluid discharge device configured to discharge a fluid into the hole to wash an exterior portion of the casing;   a casing puller disposed on the carrier and comprising a casing grip to grip the casing to lift the casing or a portion of the casing out of the borehole;   a mechanical cutter disposed on the carrier and configured to cut the casing; and   a valve disposed on the carrier and in fluid communication with at least one of the non-incendiary hole former, the fluid discharge device, the casing puller, and the mechanical cutter to control fluid energy to the at least one of the non-incendiary hole former, the fluid discharge device, the casing puller, and the mechanical cutter; and   a sensor disposed on the carrier and configured for sensing data related to positioning a downhole tool or device of the apparatus, the sensor comprising at least one of an imaging sensor or a depth sensor.   
     
     
         2 . The apparatus according to  claim 1 , wherein the non-incendiary hole former comprises a mechanical punch that extends to punch the hole in the casing. 
     
     
         3 . The apparatus according to  claim 2 , further comprising a hydraulic actuator configured to move the mechanical punch. 
     
     
         4 . The apparatus according to  claim 1 , wherein the casing puller comprises a hydraulic actuator. 
     
     
         5 . The apparatus according to  claim 1 , wherein the casing puller further comprises a slip configured to engage a wall surrounding the slip. 
     
     
         6 . The apparatus according to  claim 1 , further comprising a packer disposed on the carrier and comprising a seal to contact an interior wall of the casing to isolate a section of the casing having the hole. 
     
     
         7 . The apparatus according to  claim 6 , wherein the packer comprises a first packer disposed above the hole and a second packer disposed below the hole. 
     
     
         8 . The apparatus according to  claim 6 , wherein the valve is in fluid communication with the packer. 
     
     
         9 . The apparatus according to  claim 1 , wherein the mechanical cutter comprises a cutter blade configured to cut the casing. 
     
     
         10 . The apparatus according to  claim 9 , wherein the cutter blade comprises an extendable circular blade. 
     
     
         11 . The apparatus according to  claim 9 , wherein the mechanical cutter comprises a hydraulic motor configured to operate the cutter blade. 
     
     
         12 . The apparatus according to  claim 1 , wherein the sensor disposed on the carrier further comprises at least one of a pressure sensor, a temperature sensor, a radiation sensor, a vibration sensor, a chemical sensor, an accelerometer, and/or an acoustic sensor. 
     
     
         13 . The apparatus according to  claim 12 , further comprising a processing system for processing data received from the sensor via telemetry. 
     
     
         14 . The apparatus according to  claim 1 , wherein the carrier comprises a tubular string. 
     
     
         15 . A method for removing a casing from a borehole penetrating a formation in one run of casing removal apparatus through the borehole, the method comprising:
 conveying a carrier through the borehole;   forming a hole in the casing using a non-incendiary hole former disposed on the carrier;   washing an exterior portion of the casing through the hole using a fluid discharge device;   lifting the casing having a washed exterior or a portion of the casing having the washed exterior using a casing puller disposed on the carrier;   cutting the casing using a mechanical cutter disposed on the carrier in response to the casing puller not being able to lift the casing after the washing;   lifting the cut casing using the casing puller;   controlling fluid energy to at least one of the non-incendiary hole former, the fluid discharge device, the casing puller, and the mechanical cutter using a valve disposed on the carrier; and   sensing data related to positioning a downhole tool or device of the apparatus using a sensor disposed on the carrier, the sensor comprising at least one of an imaging sensor or a depth sensor.   
     
     
         16 . The method according to  claim 15 , wherein washing comprises identifying circulation of the fluid through the carrier to the hole and through an annulus directly exterior to the casing to the surface. 
     
     
         17 . The method according to  claim 15 , further comprising isolating an interior section of the casing having the hole using a first packer disposed on the carrier above the hole and a second packer disposed on the carrier below the hole. 
     
     
         18 . The method according to  claim 15 , further comprising setting a first packer above the non-incendiary hole former and a second packer below the non-incendiary hole former before the hole is formed. 
     
     
         19 . The method according to  claim 15 , wherein lifting comprises extending a slip from the casing puller to fix the casing puller in place by engaging a wall surrounding the slip, gripping the casing to be pulled with a casing grip, and energizing an actuator that lifts the casing grip. 
     
     
         20 . The method according to  claim 15 , wherein sensing data comprises identifying a cement top or stuck point to determine an optimal cut location. 
     
     
         21 . The method according to  claim 15 , wherein sensing data comprises locating a casing collar to avoid punching the casing collar.