Method of longitudinally splitting a pipe coupling within a wellbore

摘要

A method of removing a pipe string (36) anchored in cement (62) within a wellbore (56) involves the use of a coupling cutter (10) having a linear charge (42) that is magnetically oriented radially and rotationally within the pipe (36). The coupling cutter (10) also has a coupling sensor (24) that identifies the location of a coupling (88) electronically. One first determines the free length of pipe (36) that is above the cement (62). The coupling sensor (24) then finds the lowest coupling (88) that is just above the cement (62) level so that the liner charge (42) can be axially aligned to that coupling (88'). A magnet (18) on the cutter (10) properly orients the linear charge (42) both radially and rotationally relative to the inner wall (48) of the pipe (36). The charge (42) is detonated to longitudinally split the coupling (88'). The pipe string (36) is then disassembled and pulled from the wellbore (36).