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US 4,537,255 AGranted
Back-off tool
AssigneeJet Research Center, Inc.
InventorsJohn A. Regalbuto, Jack E. Dines
Life of this patent
Estimating the term…
Abstract
A back-off tool comprising an explosive contained in a tubular housing which will disintegrate into fine particles upon detonation of the explosive. The explosive may be in the form of pellets so as to have the capability to vary the amount of explosive force by employing different diameter pellets and different numbers of pellets in the housing. A pressure compensation arrangement may be employed.
Claims15
A back-off tool for use in a conduit in a well bore, comprising:
- a pressure-tight firing head mandrel having disposed therein a shaped booster charge;
- and
- a tubular housing secured to said firing head mandrel and having a plurality of explosive pellets disposed in mutually abutting relationship therein;
- said shaped booster charge being adapted to pierce the wall of said firing mandrel and initiate said explosive pellets, said tubular housing being adapted to substantially disintegrate upon initiation of said pellets.
1 more element
A method of backing off a conduit joint in a well bore, comprising:
- disposing, adjacent said joint, an explosive in the form of a plurality of mutually abutting explosive pellets in a non-metallic housing adapted to substantially disintegrate upon detonation of said explosive;
- pressurizing said explosive to substantially the level of pressure in said well bore adjacent said joint;
- applying torque to said joint;
- detonating said explosive and substantially disintegrating said housing while maintaining said torque;
- and
- backing off said joint subsequent to said detonation of said explosive and disintegration of said housing.
3 more elements
Dependencies are inferred from the claim text.