Methods and apparatus for removing defective casing or pipe from well bores

Claim 1

AN APPARATUS FOR REMOVING A DEFECTIVE WELL PIPE SECTION AND FOR GUIDING A REPLACEMENT SECTION OF PIPE INTO PLACE INCLUDING, AN INNER LOWERING PIPE, AN INSIDE PIPE CUTTER TOOL MOUNTED ON THE LOWERING PIPE, LINE-UP AND GUIDE MEANS CARRIED BY THE LOWERING PIPE AND HAVING A GUIDE SURFACE FITTING WITHIN THE BORE OF THE PIPE TO BE REPAIRED, A COLLAR FINDER DEVICE MOUNTED ON SAID LOWERING PIPE AND SPACED FROM THE CUTTER TOOL INCLUDING MEANS TO PROPERLY LOCATE SAID CUTTER TOOL WITH RESPECT TO A COLLAR, SAID CUTTER TOOL INCLUDING MEANS FOR ACTUATING THE CUTTER TOOL TO SEVER THE WELL PIPE AT A POINT BELOW THE DEFECT THEREIN, AND MEANS ENGAGEABLE WITH THE WELL PIPE BELOW THE POINT OF SEVERANCE FOR SUPPORTING THE CUTTER TOOL AND LINE-UP AND GUIDE MEANS AS WELL AS THE LOWERING PIPE, WHEREBY THE UPPER DEFECTIVE SECTION OF THE WELL PIPE MAY BE SEVERED BY SAID CUTTER TOOL AND REMOVED BY STRIPPING THE SAME OVER THE LOWERING PIPE AND ALSO WHEREBY SAID LOWERING PIPE AND THE LINE-UP AND GUIDE MEANS SUBSEQUENTLY GUIDE A REPLACEMENT SECTION OF WELL PIPE INTO PROPER POSITION WITHIN THE WELL.

Claim 2

AN APPARATUS FOR REMOVING A DEFECTIVE WELL PIPE SECTION AND FOR GUIDING A REPLACEMENT SECTION OF PIPE INTO PLACE INCLUDING, AN INNER LOWERING PIPE, AN INSIDE PIPE CUTTER TOOL MOUNTED ON THE LOWERING PIPE, LINE-UP AND GUIDE MEANS CARRIED BY THE LOWERING PIPE AND HAVING A GUIDE SURFACE FITTING WITHIN THE BORE OF THE PIPE TO BE REPAIRED, A COLLAR FINDER DEVICE MOUNTED ON SAID LOWERING PIPE AND SPACED FROM THE CUTTER TOOL INCLUDING MEANS TO PROPERLY LOCATE SAID CUTTER TOOL WITH RESPECT TO A COLLAR, SAID CUTTER TOOL INCLUDING MEANS FOR ACTUATING THE CUTTER TOOL TO SEVER THE WELL PIPE AT A POINT BELOW THE DEFECT THEREIN, AND MEANS ENGAGEABLE WITH THE WELL PIPE BELOW THE POINT OF SEVERANCE FOR SUPPORTING THE CUTTER TOOL AND LINE-UP AND GUIDE MEANS AS WELL AS THE LOWERING PIPE, WHEREBY THE UPPER DEFECTIVE SECTION OF THE WELL PIPE MAY BE SEVERED BY SAID CUTTER TOOL AND REMOVED BY STRIPPING THE SAME OVER THE LOWERING PIPE AND ALSO WHEREBY SAID LOWERING PIPE AND THE LINE-UP AND GUIDE MEANS SUBSEQUENTLY GUIDE A REPLACEMENT SECTION OF WELL PIPE INTO PROPER POSITION WITHIN THE WELL.

Claim 3

A METHOD OF REPLACING A DEFECTIVE CASING SECTION OF A WELL CASING LOCATED IN A WELL BORE WHICH CASING INCLUDES A PLURALITY OF WELL PIPE SECTION COUPLED TOGETHER BY CONNECTING COLLARS, COMPRISING THE STEPS OF LOWERING AN APPARATUS INCLUDING AN INSIDE CUTTER TOOL AND LINE-UP ELEMENT INTO THE WELL CASING ON AN INNER PIPE STRING, UTILIZING ONE OF THE CONNECTING COLLARS AS AN INDEX POSITION TO LOCATE THE CUTTER TOOL IN PROPER POSITION WITHIN THE CASING, OPERATING THE CUTTER TOOL TO SEVER THE CASING AT A POINT BELOW THE DEFECTIVE CASING SECTION, THEREAFTER SUPPORTING THE APPARATUS AND THE INNER PIPE WITHIN THE CASING BELOW THE POINT OF SEPERATION WITH THE LINE-UP ELEMENT SPANNING THE CUT PORTION OF THE CASING PRIOR TO REMOVING THE UPPER DEFECTIVE SECTION, WHILE THE APPARATUS AND INNER PIPE REMAIN SUPPORTED WITHIN THE WELL THUS LOCATING THE LINE-UP ELEMENT IN A POSITION TO GUIDE THE LOWER END OF A REPLACEMENT SECTION OF CASING, AND THEREAFTER LOWERING A REPLACEMENT SECTION OF CASING INTO THE WELL BORE INTO FINAL POSITION BY THREADING THE SAME OVER THE INNER PIPE AND RELATIVE TO THE UPPER END OF THE CASING STILL REMAINING IN THE WELL BORE.

Claim 4

A METHOD OF REPLACING A DEFECTIVE CASING SECTION OF A WELL CASING LOCATED IN A WELL BORE WHICH CASING INCLUDES A PLURALITY OF WELL PIPE SECTION COUPLED TOGETHER BY CONNECTING COLLARS, COMPRISING THE STEPS OF LOWERING AN APPARATUS INCLUDING AN INSIDE CUTTER TOOL AND LINE-UP ELEMENT INTO THE WELL CASING ON AN INNER PIPE STRING, UTILIZING ONE OF THE CONNECTING COLLARS AS AN INDEX POSITION TO LOCATE THE CUTTER TOOL IN PROPER POSITION WITHIN THE CASING, OPERATING THE CUTTER TOOL TO SEVER THE CASING AT A POINT BELOW THE DEFECTIVE CASING SECTION, THEREAFTER SUPPORTING THE APPARATUS AND THE INNER PIPE WITHIN THE CASING BELOW THE POINT OF SEPERATION WITH THE LINE-UP ELEMENT SPANNING THE CUT PORTION OF THE CASING PRIOR TO REMOVING THE UPPER DEFECTIVE SECTION, WHILE THE APPARATUS AND INNER PIPE REMAIN SUPPORTED WITHIN THE WELL THUS LOCATING THE LINE-UP ELEMENT IN A POSITION TO GUIDE THE LOWER END OF A REPLACEMENT SECTION OF CASING, AND THEREAFTER LOWERING A REPLACEMENT SECTION OF CASING INTO THE WELL BORE INTO FINAL POSITION BY THREADING THE SAME OVER THE INNER PIPE AND RELATIVE TO THE UPPER END OF THE CASING STILL REMAINING IN THE WELL BORE.