Arming assembly for a perforating gun
A detonator arming assembly for a perforating gun is provided. The detonator arming assembly is integrated into the bulkhead of a perforating gun, such that it can be positioned at either end of a shaped charge positioning tube. The detonator arming assembly is armed when a tandem is threaded into the perforating gun. If not armed, a premature detonation of the internal detonator does not initiate a detonation of the internal detonating cord. If armed, a detonation of the internal detonator causes the detonation of a laterally adjacent detonating cord, which is coupled to each shaped charge in the perforating gun.
1 . An arming assembly for a perforating gun, the arming assembly comprising:
a bulkhead housing defining a detonating cord cavity and an axial opening, the detonating cord cavity being laterally adjacent to the axial opening, wherein the bulkhead housing includes a spring seat at a distal end of the axial opening,
an arming module within the axial opening and including a detonator therein, the arming module being movable between a raised position and a lowered position, the arming module being spring-biased in the raised position by a compression spring that is supported by the spring seat,
an electrically conductive connector pin for transferring a firing signal to the detonator, the connector pin protruding from an upper axial surface of the bulkhead housing and being laterally offset from the axial opening,
wherein the arming module extends from the upper axial surface of the bulkhead housing in the raised position such that the detonator is axially offset from the detonating cord cavity, and wherein the arming module is seated within the axial opening in the lowered position such that the detonator is laterally adjacent to an open portion of the detonating cord cavity, wherein the arming module is dis-armed in the raised position and armed in the lowered position.
2 . The arming assembly of claim 1 , wherein the bulkhead housing is formed from a non-conductive material.
3 . The arming assembly of claim 1 , wherein the bulkhead housing includes a plurality of radial spokes coupled to an outer ring.
4 . The arming assembly of claim 1 , wherein the bulkhead housing includes a resilient latch for retaining the arming module in the lowered position.
5 . The arming assembly of claim 1 , wherein the connector pin includes a stem that protrudes from the bulkhead housing, the stem including a plurality of resiliently deformable arms that bow outward between a tip of the stem and a base of the stem.
6 . A perforating gun comprising:
an outer gun barrel;
a shaped charge positioning tube within the outer gun barrel; and
an arming assembly joined to the shaped charge positioning tube, the arming assembly comprising:
a bulkhead housing defining a detonating cord cavity and an axial opening, the detonating cord cavity being laterally adjacent to the axial opening, wherein the bulkhead housing includes a spring seat at a distal end of the axial opening,
an arming module that is slideably movable within the axial opening between a raised position and a lowered position, the arming module being spring-biased in the raised position by a compression spring that is supported by the spring seat, and
a detonator within the arming module, wherein the detonator is axially offset from the detonating cord cavity when the arming module is in the raised position, and wherein the detonator is laterally adjacent to an open portion of the detonating cord cavity when the arming module is in the lowered position,
an electrically conductive connector pin for transferring a firing signal to the detonator, the electrically conductive connector pin protruding from an upper axial surface of the bulkhead housing and being laterally offset from the axial opening,
wherein the arming module is moveable from the raised position to the lowered position in response to attachment of the outer gun barrel to a tandem, such that a detonation of the detonator while the arming module is in the lowered position occurs immediately adjacent to the detonating cord cavity.
7 . The perforating gun of claim 6 , wherein the bulkhead housing is formed from a non-conductive material and wherein the shaped charge positioning tube is formed from metal.
8 . The perforating gun of claim 6 , wherein the bulkhead housing includes a plurality of radial spokes coupled to an outer ring.
9 . The perforating gun of claim 8 , wherein the shaped charge positioning tube includes a segmented end portion extending between adjacent ones of the plurality of radial spokes.
10 . The perforating gun of claim 6 , wherein the bulkhead housing is secured within an end portion of the shaped charge positioning tube by interference fit.
11 . The perforating gun of claim 6 , wherein the bulkhead housing includes a resilient latch for retaining the arming module in the lowered position.
12 . The perforating gun of claim 6 , wherein the arming module is radially offset from the connector pin.