Well tubing cutting device

Claim 1

A DEVICE FOR SEVERING WELL TUBING AND THE LIKE COMPRISING: (A) A SHORT CYLINDRICAL, PRESSURE-RESISTANT HOUSING INCLUDING A HOLLOW BODY PORTION AND A SEPARATE END PLUG SEALINGLY CLOSING THE LOWER END OF SAID BODY; (B) SAID BODY PORTION HAVING A THICK ANNULAR SIDE WALL AND A THICK TOP WALL INTEGRAL THEREWITH; (C) SAID SIDE WALL PROVIDING A SINGLE FIRST HORIZONTAL ANNULAR GROOVE IN THE EXTERIOR SURFACE OF THE LOWER PORTION THEREOF; (D) SAID SIDE WALL PROVIDING A SECOND HORIZONTAL ANNULAR GROOVE IN THE INTERIOR SURFACE OF SAID LOWER PORTION THEREOF IMMEDIATELY BELOW SAID FIRST ANNULAR GROOVE AND SAID SIDE WALL HAVING A THIN SECTION BOUNDING THE OUTER PERIPHERY OF SAID SECOND GROOVE; (E) SAID BODY PORTION BELOW SAID FIRST ANNULAR GROOVE HAVING AN OUTSIDE DIAMETER GREATER THAN THE BODY PORTION ABOVE SAID FIRST ANNULAR GROOVE; (F) A GENERALLY CYLINDRICAL, SHAPED EXPLOSIVE CHARGE CARTRIDGE HAVING A MAIN CHARGE OF EXPLOSIVE MATERIAL WITH AN OUTWARDLY-OPENING, ANNULAR, LINED CAVITY IN THE PERIPHERY MOUNTED FACING SAID THIN SECTION OF SAID SIDE WALL AND ADAPTED UPON BEING FIRED TO PRODUCE A RADIALLY EXPANDING PLANAR CUTTING JET ADAPTED TO SEVER SAID SIDE WALL AT SAID THIN SECTION; (G) SAID CARTRIDGE BEING POSITIONED WITHIN SAID HOLLOW BODY PORTION TO PLACE THE UPPER SURFACE OF SAID MAIN CHARGE OF EXPLOSIVE MATERIAL IN A HORIZONTAL PLANE LYING BETWEEN SAID FIRST AND SECOND ANNULAR GROOVES; (H) MEANS MAINTAINING SAID CARTRIDGE IN SAID POSITION WITHIN SAID HOLLOW BODY PORTION; (I) SAID TOP WALL AND SAID CARTRIDGE PROVIDING AXIAL OPENINGS THERETHROUGH ADAPTED TO RECEIVE A PORTION OF A DETONATING FUSE; (J) SAID HOUSING AND SAID CARTRIDGE DEFINING THEREBETWEEN A SUBSTANTIALLY UNOBSTRUCTED SPACE ABOVE SAID CARTRIDGE PROVIDING AN EXPANSION CHAMBER FOR UPWARDLY ACTING FORCES PRODUCED UPON DETONATION OF SAID CARTRIDGE; (K) SAID BODY ADAPTED TO BE CLEANLY BROKEN TRANSVERSELY AT SAID FIRST ANNULAR GROOVE BY DETONATION OF SAID CARTRIDGE WHEREBY SAID BODY PORTION ABOVE SAID FIRST ANNULAR GROOVE WILL REMAIN AT SUBSTANTIALLY THE SAME DIAMETER AS BEFORE DETONATION OF SAID CARTRIDGE; AND (L) THE SIDE WALL OF SAID BODY ABOVE SAID FIRST ANNULAR GROOVE BEING OF SUFFICIENT THICKNESS AND STRENGTH TO REMAIN INTACT AND TO BE SUBSTANTIALLY UNDISTORTED AFTER SAID CARTRIDGE IS FIRED.

Claim 2

A DEVICE FOR SEVERING WELL TUBING AND THE LIKE COMPRISING: (A) A SHORT CYLINDRICAL, PRESSURE-RESISTANT HOUSING INCLUDING A HOLLOW BODY PORTION AND A SEPARATE END PLUG SEALINGLY CLOSING THE LOWER END OF SAID BODY; (B) SAID BODY PORTION HAVING A THICK ANNULAR SIDE WALL AND A THICK TOP WALL INTEGRAL THEREWITH; (C) SAID SIDE WALL PROVIDING A SINGLE FIRST HORIZONTAL ANNULAR GROOVE IN THE EXTERIOR SURFACE OF THE LOWER PORTION THEREOF; (D) SAID SIDE WALL PROVIDING A SECOND HORIZONTAL ANNULAR GROOVE IN THE INTERIOR SURFACE OF SAID LOWER PORTION THEREOF IMMEDIATELY BELOW SAID FIRST ANNULAR GROOVE AND SAID SIDE WALL HAVING A THIN SECTION BOUNDING THE OUTER PERIPHERY OF SAID SECOND GROOVE; (E) SAID BODY PORTION BELOW SAID FIRST ANNULAR GROOVE HAVING AN OUTSIDE DIAMETER GREATER THAN THE BODY PORTION ABOVE SAID FIRST ANNULAR GROOVE; (F) A GENERALLY CYLINDRICAL, SHAPED EXPLOSIVE CHARGE CARTRIDGE HAVING A MAIN CHARGE OF EXPLOSIVE MATERIAL WITH AN OUTWARDLY-OPENING, ANNULAR, LINED CAVITY IN THE PERIPHERY MOUNTED FACING SAID THIN SECTION OF SAID SIDE WALL AND ADAPTED UPON BEING FIRED TO PRODUCE A RADIALLY EXPANDING PLANAR CUTTING JET ADAPTED TO SEVER SAID SIDE WALL AT SAID THIN SECTION; (G) SAID CARTRIDGE BEING POSITIONED WITHIN SAID HOLLOW BODY PORTION TO PLACE THE UPPER SURFACE OF SAID MAIN CHARGE OF EXPLOSIVE MATERIAL IN A HORIZONTAL PLANE LYING BETWEEN SAID FIRST AND SECOND ANNULAR GROOVES; (H) MEANS MAINTAINING SAID CARTRIDGE IN SAID POSITION WITHIN SAID HOLLOW BODY PORTION; (I) SAID TOP WALL AND SAID CARTRIDGE PROVIDING AXIAL OPENINGS THERETHROUGH ADAPTED TO RECEIVE A PORTION OF A DETONATING FUSE; (J) SAID HOUSING AND SAID CARTRIDGE DEFINING THEREBETWEEN A SUBSTANTIALLY UNOBSTRUCTED SPACE ABOVE SAID CARTRIDGE PROVIDING AN EXPANSION CHAMBER FOR UPWARDLY ACTING FORCES PRODUCED UPON DETONATION OF SAID CARTRIDGE; (K) SAID BODY ADAPTED TO BE CLEANLY BROKEN TRANSVERSELY AT SAID FIRST ANNULAR GROOVE BY DETONATION OF SAID CARTRIDGE WHEREBY SAID BODY PORTION ABOVE SAID FIRST ANNULAR GROOVE WILL REMAIN AT SUBSTANTIALLY THE SAME DIAMETER AS BEFORE DETONATION OF SAID CARTRIDGE; AND (L) THE SIDE WALL OF SAID BODY ABOVE SAID FIRST ANNULAR GROOVE BEING OF SUFFICIENT THICKNESS AND STRENGTH TO REMAIN INTACT AND TO BE SUBSTANTIALLY UNDISTORTED AFTER SAID CARTRIDGE IS FIRED.