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 detonator for non-electric detonation systems for blasting charges intended to be initiated by a detonating fuse includes a passage provided in the body of the detonator for passing a detonating fuse through the passage. The detonator includes a conventional percussion cap which is immediately initiated by the detonating fuse for initiating the detonator. Also a booster charge intended for the detonator is provided with a reinforced central channel for the detonating fuse.

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: The disclosure relates to an explosive charge intended for the explosive jointing of, primarily, large-diameter pipes, such as pipeline pipes. The charge according to the invention is intended to be delivered as a unit ready to be applied immediately on site in the pipe. The only item which is not intended to be included is the detonator which is mounted in place immediately prior to blowing the charge. The charge includes, apart from explosive, also a polymer binder of a more closely defined type and gas blisters preferably in the form of microspheres of glass or plastic and metal or metal oxide powder. The scope of the invention embraces the general configuration of the charge and all components included therein.

Abstract: A field adjustable delay connector for use in detonating cord hook-ups for multi-charge blasting particularly adapted to work effectively with low energy shock or detonating cord. The delay connector is so constructed that the donor cord initiates combustion in a variable length of burning composition the length being mechanically adjustable by the blaster during hook-up.

Abstract: The disclosure relates to a method for producing charges for explosive jointing of large-diameter pipes such as pipelines. According to the invention, such charges are formed in that a strip-shaped flat explosive is wound and joined together to form a circular ring of even thickness consisting of a plurality of closely abutting layers.

Abstract: Disclosed herein is a sidewall core gun attached to the lower end of a drill string, enabling the taking of core samples from within a deviated borehole. The gun also includes an improved charge assembly, including a detonatable core and one or more deflagratable cartridge assemblies for propelling a coring bullet from the gun to the sidewall of the borehole. Coring bullets imbedded in the sidewall remain connected to the gun via steel cables, whereby the bullets may be retrieved by raising the drill string.

Abstract: A device for parting or cutting a tube by means of an explosive charge, comprising a pack of explosive annular pellets 20 and a fuse assembly. The fuse assembly comprises two mutually equal lengths of detonating fuse 10 and 11 of which one 10 extends axially through the said pack 20 and the other 11 is disposed at one end of the said pack 20. Fuse 10 extends between a first booster 17 adjacent to but not contiguous with said one end of the pack 20 and a second booster 18 at the other end of the pack 20, and fuse 11 extends between said first booster 17 and a third booster 19 at said one end of the pack 20. In this way the pack 20 is sandwiched between said second and third booster and simultaneous detonation of the pack 20 at its opposite ends is achieved, when required in use, by application of a single initiation system to the first booster 17.

Abstract: A method and apparatus for effecting the firing of a perforating gun having a plurality of vertically spaced, shaped charges wherein the firing is accomplished from the lowermost shaped charge to the uppermost shaped charge. In one modification, the detonation of the shaped charges is accomplished by a primer cord extending through all the gun sections, which is detonated only by a booster charge located in the bottom portion of the perforating gun housing. The booster charge is in fluid communication with the interior of the housing and, upon the occurrence of leakage of well fluids into the housing, the booster charge is rendered ineffective, thus preventing the firing of the perforating gun when the lower portion of the gun is filled with well fluids. In another modification, a conventional primer cord with booster charges on each end is inserted in each gun section, as is a length of flame-transmitting tubing.

Abstract: A method and apparatus for effecting the assembly and arming a multisection perforating gun for a subterranean well. Each of the gun sections has a plurality of vertically and angularly spaced shaped charge containers disposed with the primer ends located in concentric fashion about the vertical axis of the gun, thus defining an axial passage communicating with the bores of hollow nipples which respectively effect securement of one gun section to the next adjacent gun section. In one modification, a continuous primer cord is stored on a reel below the lowermost gun section and is then pulled successively upwardly through each of the additional gun sections as they are assembled. In another modification, each of the gun sections is provided with a length of fusible guide tubing interposed between the inner primer ends of all of such shaped charges and the continuous length of primer cord is fed downwardly through the axial passage defined by such guide tubing.

Abstract: Detonation apparatus constituting a novel detonation amplifier is disclosed herein having a container enclosing a quantity of combined liquid compositions into which a detonation chamber is submerged. A pyrotechnic charge is suspended with the chamber which is surrounded by the liquid explosive composition. Apertures are provided in the wall of the chamber for permitting the liquid composition to enter the chamber. Activation of the pyrotechnic charge detonates the liquid composition within the chamber which, in turn, detonates the bulk quantity of the liquid composition in the container. In another form, the detonation amplifier includes a shaped charge producing a shock wave reflected back from a baffle to detonate the bulk quantity of the liquid composition in the container.

Abstract: An explosive booster which contains a secondary high explosive material of such density that it is capable of receiving a detonation from one secondary high explosive mass, across a discontinuity, and of then detonating and transmitting the detonation to another secondary high explosive mass. The explosive booster is produced by compacting the secondary high explosive material to a density such that the booster is capable of acting as both an acceptor and donor of a detonation. The explosive booster may be used to transfer a detonation from one secondary high explosive mass to another such mass as for example in detonating a string of perforating guns within wellbores in the oil and gas industry.

Abstract: A cylindrical housing for a shock-augmenting charge is provided with axially extending grooves in its outer wall to enhance its radial detonation capability. When used in a cylindrical warhead for augmenting detonation of a main charge of insensitive high explosive, full detonative output is enabled and in addition, a flatter detonation wavefront is generated within the main charge, thereby reducing the need for supplementary waveform shapers.

Abstract: A perforating gun having a plurality of shaped charges to be detonated by a primacord positioned adjacent thereto, which primacord is to be actuated by a detonator positioned in detonating proximity to the primacord. The gun of the present invention mounts the primacord and/or detonator within the gun in a manner affording the relative movement therebetween to a position where the primacord and the detonator are non-aligned so as to safe-arm the gun. The relative movement between the primacord and the detonator can be accomplished through the gun carrier so as to simplify the detonation system and minimize any lengthening of the gun required to accomplish the safe-arming.

Abstract: A blasting cap to primer adapter permits the use of any size of a blasting cap and associated shock tube in combination with commercially available primers and detonating cords. In one embodiment, a bracket arrangement and cord tunnel assembly having a plurality of tunnels is employed attachable to a primer having a tunnel through which an associated blasting cap shock tube may be looped, while a length of detonating cord may be similarly directed through the tunnel assembly of the adapter. An ignition of the detonating cord will result in a concurrent ignition of the shock tube to effect the desired explosion of the primer. Through this construction, any number of primers and blasting cap arrangements can be attached to and ignited by a single detonating cord.

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: An improved booster construction having a metallic covering with a plural of apertures therein encases a booster charge which, in turn, is encased in a nonmetallic cup having a low temperature melting characteristic permitting the booster charge to expand during thermal cook-off to prevent reaching critical temperature pressure relationships.

Abstract: An explosive booster is provided for the detonation of insensitive blasting agents. The booster contains TNT as the sole explosive ingredient, is sensitive to blasting cap initiation yet remains insensitive to impact initiation. The booster comprises an elongate structure having a gradually increasing density from end to end, only the less dense end being cap sensitive. Reduced density is accomplished by the incorporation of voids or pockets, by means of, for example, glass microspheres. Particulate sodium nitrate and vermiculite are included as density enhancers.

Abstract: An explosive safe-arming apparatus for use with a perforating gun which includes a fixed barrier disposed between a detonator explosive and a booster explosive, and a movable barrier disposed between laterally facing portions of the detonator and booster explosives. Upon actuating the movable barrier, either a predetermined perforator disarming operating position or perforator arming operating position are obtained.

Abstract: An explosive-containing casing is provided with a cap to which a nipple is secured. The nipple supports a rigid rod which extends the length of the casing and which in turn supports a detonation train for the explosives within the casing. An electrical connector arrangement is joined to the nipple to permit a conductive path to be established to a detonator which forms part of the detonation train. The nipple is secured to the cap in a manner which prevents the entry of water or other undesirable substances into the casing.

Abstract: A linear explosive charge with constant detonation velocity, comprising a plurality of series-coupled explosive units or sticks. All sticks are identical and comprise a tubular member of selected length, with matched couplings. A helix of explosive cord is positioned around the tubular member, with ends inserted through openings into the interior of the tube and out through the couplings. At the top end of the stick a length of elastic tube is inserted, over the projecting cord, into the top coupling. When two sticks are to be coupled, the downward projecting cord of the top stick is inserted into the elastic tube along side the starting end of the cord of the second stick. This stretches the tube, which presses the two cords into intimate cross-detonation condition. Small ring-shaped concentrated explosive units can be inserted into the bottom end of the top stick over the explosive cord, as synchronous booster charges.

Abstract: A chub cartridge has a tubular chamber containing a water-bearing blasting agent, and a longitudinal tunnel adjacent to the tubular chamber and integral therewith. Preferably, the tunnel is full-length and continuous and has holes for threading a detonating cord therethrough and for holding a cord firmly against the tubular chamber for the cord-priming of the cartridges. In primer assemblies, the tunnel also can be used to hold a cap/booster in place, and for lacing cap wires or a low-energy detonating cord. A preferred cartridge is made continuously in a series by wrapping a web of film having a row of holes along one edge so as to form a tube and an outer flap containing the holes, and sealing the tube and the flap so as to form a tunnel containing the holes in its outer portion, the wrapping being performed so that either the inner or outer portion of the tunnel is circumferentially longer than the other.

Abstract: A detonation initiator for use in explosive warheads to cause dual-end ination of the explosive within the warhead. An initiation transfer tube positioned interiorly and centrally within the warhead explosive contains a primary ignitor attached to a plurality of explosive trains leading to secondary ignitors. Booster plates positioned at either end of the explosive charge and adjacent the secondary ignitors detonate the explosive at either end causing the detonating front to travel toward the center of the explosive causing a great force to extend radially outward centrally from either end of the explosive. An initiation transfer tube positioned concentric with the explosive provides for an explosive output initiating from a single point at the center of the warhead to its ends without destroying or damaging the warhead.

Abstract: An explosive booster cap containing a confined detonable charge, said confinement providing a high degree of water protection for said detonable charge, but which confinement will, when the booster cap is subjected to a fire or excessive heat, be disrupted to allow for outgassing and burning of the detonable charge without explosion. Confinement of the detonable charge is provided by a thermoplastic plug inserted into the open end of the booster cap. The physical properties of the thermoplastic plug permit the plug to deform when heated to a temperature between the decomposition and initiation temperatures of the explosive. The booster cap is slipped over the detonable end of the blasting cap, the resultant combination providing a substantially enhanced explosive output.

Abstract: A method of charging a borehole with at least first and second separate sections of explosive material, which method comprises the steps of providing a detonating cord extending into the borehole, providing a first primer on a first carrier having a time delay connection between the cord and the first primer, this time delay having a first selected value, providing a second primer on a second carrier having a time delay connection between a cord and the second primer, the time delay of the second carrier having a second selected value different from the first selected value, sliding the first carrier and primer along the cord and into detonation association with the first section of explosive material and sliding the second carrier and primer along the same cord to detonation association with the second section of explosive material.