Abstract: A wellbore completion system utilizes casing conveyed devices to establish a fluid communication path between a downhole formation and the casing string. Extendible pistons are mounted in the wall of the casing pipe string and are extended toward contact with the downhole formation after the casing is set. An explosive device is mounted in the pistons and includes a detonator and a shaped charge. The detonator is housed in a plug threaded into one end of the piston. The shaped charge is housed in a canister conveniently inserted into the other end of the piston. The explosives included in the system may thus be conveniently assembled at the well site. Explosive in the pistons are activated by a separately conveyed activation system which produces a pressure wave to detonate the explosives and establish fluid communication between the casing and formation.

Abstract: A fluid actuated detonating device is shown being used to activate explosive devices in a borehole. The detonating device has an explosive detonation charge arranged in a housing wherein a rupture disc in the wall of the housing separates the explosive charge from a fluid environment so that when pressure in the fluid environment is raised to a sufficient level the rupture disc fails and communicates a sudden pressure wave to the explosive to detonate the explosive.

Abstract: An improved plastic-bonded explosive composition which includes from 2 wt. % up to 30 wt. % of a nitrocellulose binder and comprises incorporating into the composition during preparation from about 0.0025 wt. % up to a value less than 2 wt. % of fibrillatable polytetrafluoroethylene (PTFE) and mixing the composition thoroughly and with sufficient shearing action whereby the PTFE fibrillates and becomes substantially uniformly distributed throughout the finished composition.

Abstract: An improved connector for holding low energy detonating cord adjacent the percussion-actuation and surface of a detonator comprises a plastic tube having a detonator-receiving bore and one or more cord receiving transverse bores between a plastic end closure for the tube and the end of the bore of the tube. The transverse bore(s) form channels which permit the cord segments therein to span the actuation end surface of the detonator and result in improved reliability of initiation of the detonator.

Abstract: An explosive primer unit adapted to be initiated instantaneously by low energy detonating cord when the unit comprises an explosive primer and an explosive coupler which operatively joins the low energy detonating cord to the primer.

Abstract: A primer assembly for use in the non-electric initiation of cap-insensitive explosives, especially of deck-loaded explosive charges by means of a single downline of low-energy detonating cord (LEDC), includes a percussion-actuated detonator seated in a cavity in a high-energy primer, and an explosive coupler in which a coupling explosive charge, housed in a plastic connecting block, is in initiating proximity to the detonator's percussion-sensitive ignition charge and sufficiently close to a cord-receiving perforation or conduit in or adjacent the primer as to be initiatable by the detonation of LEDC threaded therethrough. A preferred connecting block has means for engaging the detonator, and means for attaching the block to the primer. Preferably the explosive coupler is seated within a block-like cavity in the primer.

Abstract: An explosive primer unit in which the degree of energy coupling between a low-energy detonating cord (LEDC) and an explosive coupling element in a cast explosive primer is maximized; the unit contains (a) a substantially cylindrical charge of cast explosive having a perforation therein aligned substantially parallel to the charge's cylindrical axis, and sized to slidably receive a length of LEDC and (b) embedded in the cast explosive charge along the LEDC-receiving perforation, an explosive coupling element containing a shock-sensitive high-velocity detonating explosive having a tubular body having a wall that surrounds, and a bore that forms, the LEDC-receiving perforation over at least a portion of the perforation's length, the size of the bore of the coupling element's tubular body that forms the LEDC-receiving perforation in the cylindrical charge of cast explosive closely matching the outer diameter of a length of LEDC to be received therein.

Abstract: A non-electric detonator device having a tubular shell that is closed at its bottom end and containinga base charge of a detonating explosive at the bottom of the shell,a priming charge of a heat sensitive detonating explosive composition adjacent to the base charge,a rupturable membrane that seals the top end of the shell and forms an open volume between the priming charge and the top end of the shell anda holder for holding a low energy detonating cord (LEDC) in abutting relationship to the membrane:whereby on detonation of the LEDC the membrane is ruptured and the priming charge is initiated which in turn initiates the detonating explosive.

Abstract: A primer assembly for use in the non-electric initiation of cap-insensitive explosives, especially of deck-loaded explosive charges by means of a single downline of low-energy detonating cord (LEDC), includes a percussion-actuated detonator seated in a cavity in a high-energy primer, and an explosive coupler in which a coupling explosive charge, housed in a plastic connecting block, is in initiating proximity to the detonator's percussion-sensitive ignition charge and sufficiently close to a cord-receiving perforation or conduit in or adjacent the primer as to be initiatable by the detonation of LEDC threaded therethrough. A preferred connecting block has a U-shaped channel for engaging the detonator, and a connecting block arm for attaching the block to the primer. Preferably the explosive coupler is seated within a block-like cavity in the primer.

Abstract: A carrier for supporting a primer explosive charge in operative relationship to initiating means therefor comprises a cup having a recessed portion in its closed bottom end for engaging an explosive-containing plastic connecting block, used to explosively couple a low-energy detonating cord (LEDC), threaded through a tunnel in the cup, to a percussion-actuated detonator seated in a cavity (cap well) in the cup. A number of such primers can be made to slide on a single LEDC downline for placement in decked explosive charges in a borehole. Two tubular members project into the cup from the recessed portion, forming one or two cord-threading tunnels and a cap well. Besides initiation of a detonator by an LEDC downline via the explosive coupler, the carrier allows the primer charge to be initiated by a high-energy detonating cord or an electric detonator in an axial tunnel in the cup, or by a length of LEDC threaded through a tunnel and connected to a non-electric detonator seated in the cap well.

Abstract: An assembly for initiating a detonating explosive charge, e.g., a surface seismic charge, by low-energy detonating cord (LEDC) has a cord-connector fitted around a percussion-actuated detonator or booster, and a means of piercing a frangible package to enable the assembly to be embedded in the charge. In a preferred assembly, the connector is a plastic tube which fits over the actuation end of a booster shell whose opposite end is notched or serrated. A detonator preferably is fitted in a plastic cord-connecting tube whose end surface is tapered, or which has a pointed extension member, forming a spike. LEDC does not pose the fire hazard encountered with heavier cords in surface seismic operations in wooded or grassy areas.

Abstract: An explosive booster, useful as a starter for one or more low-energy explosive connecting cords, e.g., low-energy detonating cord (LEDC), comprises a detonating explosive charge in the form of a rod having at least one longitudinal perforation for threading one or more (receiver) cords to be initiated by the booster explosive charge, which in turn is initiated by a blasting cap or preferably by the side-output of a (donor) detonating cord in contact therewith. A preferred rod has multiple perforations for threading multiple receiver cords, and is housed within a rigid plastic connector having a portion of its wall circumferentially cut out to allow a donor cord to contact the thereby-exposed rod therein. A trunkline cord is thereby adapted to initiate multiple downlines via a single booster.

Abstract: Improved uniformity of timing, and particularly reduced sensitivity of timing to minor variations in delay charge size, are achieved in delay detonators by placing a loose load of a flame-sensitive ignition composition between a pressed delay charge and an ignition assembly, e.g., a percussion primer, at the actuation end of the detonator. The loose ignition charge has a free surface and is adapted to be ignited in response to direct contact with flame emitted from the ignition of a charge in the ignition assembly. Preferably, the delay charge is pressed into a plastic carrier which, in a non-electric detonator, has an open end terminating between the walls of the detonator shell and a primer shell that closes the actuation end of the detonator, and the ignition charge is loosely loaded into a metal capsule seated against the delay charge.

Abstract: A detonator closed at one end by a primer shell whose integrally closed end has a percussion-sensitive primer charge supported adjacent its inside surface, and its outside surface disposed across the end of the detonator shell, is actuated by the detonation of one or two lengths of low-energy detonating cord (LEDC) adjacent the primer shell's outside end surface, a single length of LEDC being arrayed in a manner such that a pair of axially separated segments thereof, or two lengths arrayed in a manner such that a segment from each length, is anchored in place in side-by-side relationship adjacent said surface. This cord array assures reliable ignition of a center- or rim-fired percussion primer by means of the side-output of LEDC even with explosive core loadings at the low end of the LEDC loading range.

Abstract: A percussion-actuated instantaneous or delay detonator transmits a detonation from a first length of low-energy detonating cord (LEDC) transversely positioned adjacent the detonator's percussion-responsive end to a U-shaped segment of a second length of LEDC held with its apex against the base-charge end of the detonator and the arms of the U extending away from the detonator. A directional connector for connecting one or more U-shaped segments of detonating cord adjacent each end of the detonator has identifiable donor- and receiver-cord-housing sections, e.g., the receiver-cord-housing section has the shape of the head, and the donor-cord-housing section the shape of the butt, of an arrow. A connector adapted to hold receiver LEDC and high-energy detonating cord (HEDC) segments is internally configured to receive nested U-shaped segments of LEDC and HEDC only when the LEDC is adjacent the base-charge end of the detonator.

Abstract: An improved low-energy detonating cord, which is light-weight, flexible, strong, and non-conductive, detonates at high velocity, and is readily adapted to high-speed continuous manufacturing techniques, has a continuous solid core of a deformable bonded detonating explosive composition comprising a crystalline high explosive compound, preferably superfine PETN, admixed with a binding agent, the crystalline explosive loading being about from 0.5 to 10 grains per foot (0.1 to 2 grams per meter) of length; and, enclosing the core, a protective plastic sheath, e.g., about 0.005-0.075 inch (0.127-1.905 mm) thick, no metal or woven textile layers being present around the core or sheath. Perferably, one or more continuous strands of reinforcing yarn, e.g., running substantially parallel to the core's longitudinal axis, are located between the core and the plastic sheath, or in or around the sheath.

Abstract: An explosive booster capable of being connected to donor and receiver detonating cords in the field via a cord-connector to propagate a detonation from the donor cord to the receiver cord, at least one of which cords is a low-energy detonating cord, has a granular explosive charge, e.g., PETN, between the walls and closed bottoms of inner and outer shells, the inner shell having an axial open cavity and the explosive charge being sealed off from the atmosphere. A length of detonating cord is inserted into the cavity of the booster in a manner such that an end-portion thereof is surrounded by the granular explosive in the spacing between the walls of the shells, the cord being held in the cavity by retention means located preferably in the cavity. Another length of detonating cord is positioned transversely outside and adjacent to the closed end of the outer shell, preferably in a transverse slot in a tube which holds the booster.

Abstract: An improved low-energy detonating cord, which is light-weight, flexible, strong, and non-conductive, detonates at high velocity, and is readily adapted to high-speed continuous manufacturing techniques, has a continuous solid core of a deformable bonded detonating explosive composition comprising a crystalline high explosive compound, preferably superfine PETN, admixed with a binding agent, the crystalline explosive loading being about from 0.5 to 10 grains per foot (0.1 to 2 grams per meter) of length; and, enclosing the core, a protective plastic sheath, e.g., about 0.005-0.075 inch (0.127-1.905 mm) thick, no metal or woven textile layers being present around the core or sheath. Preferably, one or more continuous strands of reinforcing yarn, e.g., running substantially parallel to the core's longitudinal axis, are located between the core and the plastic sheath, or in or around the sheath.

Abstract: A process of preparing rebonded structures from a composition which includes both particulate elastomeric foam and pneumacel fibers.