초록 ▼

A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at oppos

A pipe severing tool is arranged to align a plurality of high explosive pellets along a unitizing support structure whereby all explosive pellets are inserted within or extracted from a tubular housing as a singular unit. Electrically initiated exploding wire detonators (EBW) are positioned at opposite ends of the tubular housing for simultaneous detonation by a capacitive firing device. The housing assembly includes a detachable bottom nose that permits the tool to be armed and disarmed without disconnecting the detonation circuitry. Because the tool is not sensitive to stray electrical fields, it may be transported, loaded and unloaded with the EBW detonators in place and connected.

대표청구항 ▼

1. An apparatus for explosively severing a length of pipe having an internal flowbore, said apparatus comprising: a tubular exterior housing having an interior barrel extending between opposite distal ends of the barrel, said housing having electrically initiated explosive detonation means at opposi

1. An apparatus for explosively severing a length of pipe having an internal flowbore, said apparatus comprising: a tubular exterior housing having an interior barrel extending between opposite distal ends of the barrel, said housing having electrically initiated explosive detonation means at opposite distal ends of said barrel; and a plurality of high explosive pellets assembled separate from said housing in axial alignment and structurally bound together as a singular and independent unit without detonation means, said unit of explosive pellets being configured to be selectively inserted within said barrel and withdrawn unexploded therefrom as a single unit.2. An apparatus as described by claim 1 wherein the detonators respective to said opposite distal ends of said barrel are connected for simultaneous detonation.3. An apparatus as described by claim 2 wherein said opposite end detonators resiliently bear compressively against respective ends of said pellet unit.4. An apparatus as described by claim 2 wherein one end of said exterior housing is selectively detached, with one of said detonators, from the remainder of said exterior housing for loading said pellet unit into said barrel.5. A method of severing a length of pipe having an internal flow bore comprising the steps of:assembling a plurality of high explosive pellets into a structurally independent unit;depositing said independent unit into a tubular barrel;resiliently engaging at least one end of said independent unit with explosive detonator means by translational movement of said independent unit into said barrel;positioning said tubular barrel within said flow bore at a predetermined location along the length of said flow bore; and,electrically initiating said detonator means.6. A method of severing a length of pipe as described by claim 5 wherein detonator means engage opposite ends of said independent unit of high explosive pellets.7. A method of severing a length of pipe as described by claim 6 wherein opposite end detonator means are simultaneously initiated.8. A method of severing a length of pipe as described by claim 5 wherein said plurality of high explosive pellets are unitized in a column separate from said tubular barrel and inserted in said tubular barrel as a singular unit prior to positioning said barrel within said flow bore.9. A method of severing a length of pipe as described by claim 8 wherein said plurality of pellets are formed for meshed engagement with unitizing structure whereby said unitizing structure and meshed pellets are inserted within or removed from said tubular barrel as a singular unit.10. An apparatus for explosively severing a length of pipe, said apparatus comprising:(a) a tubular housing having an internal barrel space extending between opposite distal ends of said housing, said barrel space being configured to accommodate a column of explosive material between said distal ends;(b) a selectively removed end closure for environmentally sealing one distal end of said barrel space; and,(c) explosive detonation means disposed proximate of each distal end for substantially engaging said column of explosive material, at least one said detonation means secured to said selectively removed end closure.11. An apparatus for explosively severing a length of pipe as described by claim 10 wherein detonation means disposed at a distal end of said barrel space opposite from said removable end closure is resiliently biased toward said end closure.12. An apparatus for explosively severing a length of pipe as described by claim 10 wherein said detonation means are electrically initiated and are linked by electrical continuity for substantially simultaneous detonation.13. An apparatus for explosively severing a length of pipe as described by claim 12 wherein said electrical continuity is sustained during a physical separation of said end closure from said barrel space.14. An apparatus for explosively severing a length of pipe, said apparatus comprising:(a) a tubular housing having an internal barrel space extending between opposite distal ends of said housing, said barrel space being configured to accommodate a column of explosive material between said distal ends;(b) a selectively removed end closure for environmentally sealing one distal end of said barrel space;(c) electrically initiated detonation means disposed proximate of each distal end with at least one detonation means secured to said selectively removed end closure; and,(d) electrical continuity linking said detonation means for substantially simultaneous ignition, said continuity being sustained while said end closure is removed from said one distal end of said barrel space.15. An apparatus for explosively severing a length of pipe as described by claim 14 wherein detonation means disposed at a distal end of said barrel space opposite from said removable end closure is resiliently biased toward said end closure.16. An apparatus for explosively severing a length of pipe, said apparatus comprising:(a) a tubular housing having an internal barrel space extending between opposite distal ends of said housing;(b) a selectively removed end closure for environmentally sealing one distal end of said barrel space;(c) electrically initiated detonation means disposed proximate of each distal end with at least one detonation means secured to said selectively removed end closure;(d) electrical conductors linking said detonation means for substantially simultaneous ignition; and,(e) an explosive loading assembly for unitizing a column of explosive independently of said housing, said unitized column of explosive being selectively inserted as a singular unit into said barrel space by the removal of said end closure from the one distal end of said barrel space without interrupting conductor continuity of an electrically conductive linkage among said detonation means.17. An apparatus for explosively severing a length of pipe, said apparatus comprising:(a) a tubular housing having an internal barrel space extending between opposite distal ends of said housing;(b) a selectively displaced end closure for environmentally sealing one distal end of said barrel space;(c) electrically initiated detonation means disposed proximate of each distal end with at least one detonation means secured to said selectively displaced end closure;(d) electrical conductors linking said detonation means for substantially simultaneous ignition; and,(e) an explosive loading assembly for unitizing a plurality of explosive pellets about a substantially central rod-like structure independently of said housing and said detonating means, said unitized plurality of explosive pellets being selectively inserted as a singular unit within said barrel space between said detonation means by the displacement of said end closure from the one distal end of said barrel space without interrupting conductor continuity of an electrically conductive linkage among said detonation means.18. An apparatus for explosively severing a length of pipe, said apparatus comprising:(a) a tubular housing having an internal barrel space extending between opposite distal ends of said housing;(b) a selectively removed end closure for environmentally sealing one distal end of said barrel space;(c) electrically initiated detonation means disposed proximate of each of said distal ends with at least one detonation means secured to said selectively removed end closure;(d) electrical conductors linking said detonation means for substantially simultaneous ignition; and,(e) an explosive loading assembly for unitizing an axial column of explosive pellets about a substantially central rod-like structure, said rod-like structure having a first length, the assembly of said explosive pellets extending along said rod-like structure for a second length, said first length being greater than said second length to provide a manual handling extension of said rod-like structure for manually inserting and removing undetonated pellets relative to said barrel space.19. An apparatus for explosively severing a length of pipe, said apparatus comprising:(a) a tubular housing having an internal barrel space extending between opposite distal ends of said housing;(b) a selectively displaced end closure for environmentally sealing one distal end of said barrel space;(c) electrically initiated detonation means disposed proximate of each distal end with at least one detonation means secured to said selectively displace end closure;(d) electrical conductors linking said detonation means for substantially simultaneous ignition;(e) an explosive loading assembly for unitizing an axial column of explosive pellets about a substantially central rod-like structure, said rod-like structure having a first length and said explosive pellets assembled along said rod-like structure for a second length that is less than said first length to provide a manual handling extension of said rod-like structure for inserting and removing undetonated pellets relative to said barrel space; and,(f) receptacle space within said end closure to accommodate said rod-like structure extension when said end closure seals said one distal end of said barrel space.20. An apparatus for explosively severing a length of pipe, said-apparatus comprising:(a) a tubular housing having an internal barrel space extending between opposite distal ends of said housing;(b) a selectively displaced end closure for environmentally sealing one distal end of said barrel space;(c) electrically initiated detonation means disposed proximate of each distal end with at least one detonation means secured to said selectively displaced end closure and a detonation means respective to the other end of said barrel space having a resilient bias toward the said one end;(d) electrical conductors linking said detonation means for substantially simultaneous ignition; and,(e) an explosive loading assembly for unitizing a column of explosive independently of said housing, said unitized column of explosive being selectively inserted as a singular unit within said barrel space against the bias of said other end detonation means by the displacement of said end closure from the one distal end of said barrel space without interrupting conductor continuity of an electrically conductive linkage among said detonation means.21. A well pipe severing method comprising the steps of:(a) fabricating an explosive enclosure tube having an elongated explosive receptacle space extending between opposite distal ends, one of said distal ends comprising a removable tube end closure;(b) positioning electrically initiated detonators at said distal ends, at least one of said detonators positioned on said removable end closure;(c) at a first location distal from a well pipe, arming said detonators by connecting an electrically conductive linkage between detonators at opposite distal ends of said receptacle space;(d) transporting said tube with said armed detonators to a second location proximate of a well pipe, said tube being substantially devoid of high explosive material between said armed detonators during such transport;(e) at said second location, separating said removable end closure from said enclosure tube to insert a column of explosive material into said receptacle space without interrupting said electrically conductive linkage between said detonators; and,(f) replacing said end closure to environmentally seal said receptacle space and engage opposite ends of said explosive column by said armed detonators;(g) connecting said armed detonators to a controlled energy source;(h) positioning said enclosure tube at a desired position within said well pipe; and,(i) discharging said detonators.22. A method of severing a length of pipe comprising the steps of:(a) assembling a plurality of high explosive pellets into a singular, structural unit having no detonation means combined therewith;(b) depositing said structural unit into a tubular barrel; engaging a first detonation means by said unit as it is deposited into said barrel, said first detonation means being secured to one end of said tubular barrel and resiliently biased toward an opposite end of said barrel;(c) environmentally enclosing said unit within said barrel by returning a selectively removed barrel end closure, said end closure having a second detonation means secured thereto, an electrically conductive link between said first and second detonation means remaining uninterrupted as said unit is inserted into said tubular barrel;(d) positioning said tubular barrel within a pipe flow bore; and,(e) electrically initiating said detonator means.23. A method of severing a length of pipe comprising the steps of:(a) assembling a columned unit of explosive by aligning a plurality of high explosive pellets serially along a portion of the length of a rod-like structure that projects through an aperture in said pellets, the length of said structure being greater than a serial assembly length of said pellets;(b) assembling an environmental enclosure having a detachable end closure for a tubular barrel space within said enclosure, a first detonation means resiliently secured to one end of said barrel space and a second detonation means secured to said detachable end closure, said detonation means being connected by electrical conductors;(c) inserting said explosive unit into said barrel space without disturbing an electrical continuity of connections between said detonation means;(d) enclosing said explosive unit within said barrel space by positioning said detachable end closure;(e) selectively connecting said electrical conductors to an electrical energy source;(f) positioning the combination of said environmental enclosure and said explosive unit within a pipe flow bore; and,(g) electrically initiating said detonator means.