Abstract: A perforating gun apparatus includes an elongated radially resilient carrier with a plurality of capsule type shaped charges attached to the carrier in a circumferentially phased pattern. The carrier is capable of passing downward through restricted diameter openings and subsequently expanding so as to hold the shaped charges with a near zero standoff from the well bore which is to be perforated.

Abstract: A detonation shock wave perforating system for use in perforating subsurface earth formations traversed by a borehole. The system includes a plurality of mechanically serially connected perforating gun sections, each section of which may contain a plurality of shaped charges mounted therein and a length of detonator cord. To provide coupling of the detonation shock wave between housing sections, a booster is coupled to the detonator cord and mounted proximate a shaped charge having its axis of perforation aligned along the longitudinal axis of the gun. Detonation of the shaped charge results in a jet which detonates a quantity of explosive material in the subsequent gun section the detonation of which transfers a detonation shock wave into a detonator cord, thereby detonating any explosive connected thereto. An alternate embodiment provides for coupling of the detonator wave without using a shaped charge unit.

Abstract: A well coring apparatus is provided with the capability for monitoring the length of the core in the inner barrel (32) of a core barrel (16) and the rate at which the core enters the inner barrel (32). The device includes a Sonic Core Monitor (78) which is disposed in the upper end of the inner barrel (32) and a piston (68) which is disposed in the lower end thereof. The inner barrel (32) is filled with a pressurized fluid. The Sonic Core Monitor (78) generates an ultrasonic pulse that is transmitted down to the surface of the piston (68) and reflected back up to the Sonic Core Monitor (78). The time between the transmitted and received pulse is then measured and distance determined therefrom. Both length of core and rate of core entry into the inner barrel (32) can then be determined. If the core is proceeding at too slow a rate, a valve (50) can be opened to allow drilling fluid to bypass the core barrel (16). This provides the surface operator with an indication that a jam has occurred.

Abstract: A perforating gun is designed to have explosive charges spirally disposed around its circumference in accordance with a displacement angle defined as (m/p)(360.degree.), where p is a whole number greater than 4 and m is a whole number greater than 1 but less than (p-1) and where m/p is an irreducible fraction. A U, or horseshoe, shaped retainer clip holds individual charges in respective holes and cavities of an outer carrier tube and an inner carrier tube to prevent horizontal or transverse movement of each charge and thereby hold it in contact with an axially extending detonator cord.

Abstract: A shaped charge carrier assembly includes a strip type carrier having openings therein for receiving shaped charges. Each of the openings includes first and second diagonally opposed pairs of resilient tabs for snugly engaging an outer case of the shaped charge. In a preferred embodiment, every second one of the openings includes first and second elongated cord receiving slots communicated therewith, so that the assembly can be put together without threading a free end of a firing cord through openings in the carrier. Integral intermediate portions of the firing cord can be placed through the alternate openings in the elongated cord receiving slots associated therewith without threading the free ends of the firing cord therethrough.

Abstract: A perforator for perforating a subsurface formation surrounding a well bore to ensure perforation of channels in a cement sheath surrounding a casing pipe cemented in said well bore comprising a series of stacked plates, each plate containing spaced apart co-planar, pie-shaped linear charges and a co-planar, pie-shaped non-charged spacer arranged between each of said linear charges. There are preferably four linear charges and four non-charged spacers forming each plate. The linear charges on each plate are spaced angularly from the linear charges on each other plate so that the linear charges are aimed at different angular portions of the bore hole.

Abstract: A shaped charge perforating unit includes a housing having a cavity formed therein. An explosive charge of high explosive material is retained within the cavity by a liner of non-explosive material. The explosive charge consists of quantities of two explosive materials having different detonation sensitivities.

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 shaped charge carrier assembly is provided for use in a perforating gun of the type used to perforate oil or gas wells. The assembly includes at least one shaped charge including an outer case having an outer surface and a first shoulder extending radially outward from the outer surface. The assembly also includes a carrier having an opening therethrough large enough to receive the outer surface of the case, and having a resilient tab extending into the opening for frictionally engaging at least a first portion of the outer surface of the case, and for thereby holding the shaped charge in place relative to the carrier with the shoulder of the shaped charge abutting the carrier.

Abstract: A method and apparatus for deactivating a partially flooded perforating gun assembly utilizes a fuse which extends downwardly to the lower end of a perforating gun section and is then associated with an explosive coupler having a means for interrupting the transmission of an explosive force upon the presence of undesired fluid in the lower end of the gun section.

Abstract: A detonation shock wave perforating system for use in perforating subsurface earth formations traversed by a borehole. The system includes a plurality of mechanically serially connected perforating gun sections, each section of which may contain a plurality of shaped charges mounted therein and a length of detonator cord. To provide coupling of the detonation shock wave between housing sections, a booster is coupled to the detonator cord and mounted proximate a shaped charge having its axis of perforation aligned along the longitudinal axis of the gun. Detonation of the shaped charge results in a jet which detonates a quantity of explosive material in the subsequent gun section the detonation of which transfers a detonation shock wave into a detonator cord, thereby detonating any explosive connected thereto. An alternate embodiment provides for coupling of the detonator wave without using a shaped charge unit.

Abstract: An apparatus for effecting the firing of a multisection 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. The detonation of the shaped charges is accomplished by a primer cord which is detonated only by a booster charge located in the bottom portion of the assembled perforating gun housing. Hollow nipples are utilized to effect the assembly of the plurality of tubular gun sections in axially stacked relationship and a fusible tubular guide element is provided between each adjacent pair of nipples so as to permit a continuous primer cord, as well as a fusible cord, to be concurrently inserted throughout the length of the gun.

Abstract: A well coring apparatus is provided with the capability for monitoring the length of the core in the inner barrel (32) of a core barrel (16) and the rate at which the core enters the inner barrel (32). The device includes a Sonic Core Monitor (78) which is disposed in the upper end of the inner barrel (32) and a piston (68) which is disposed in the lower end thereof. The Sonic Core Monitor (78) generates an ultrasonic pulse that is transmitted down to the surface of the piston (68) and reflected back up to the Sonic Core Monitor (78). The time between the transmitted and received pulse is then measured and distance determined therefrom. Both length of core and rate of core entry into the inner barrel (32) can then be determined. If the core is proceeding at too slow a rate, a valve (50) can be opened to allow drilling fluid to bypass the core barrel (16). This provides the surface operator with an indication that a jam has occurred.

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: Methods are provided for manufacturing a shaped charge carrier from a generally cylindrical thin wall tube. A plurality of flat areas are formed on the cylindrical tube, and an opening through the tube is associated with each of the flat areas for receiving a shaped charge therein.

Abstract: A shaped charge carrier for a perforating gun includes a generally cylindrical thin wall carrier tube, a plurality of flat areas formed on the carrier tube, and an opening through each of the flat areas for receiving a shaped charge therein.

Abstract: In accordance with the present invention, rotation of the inner barrel relative of the axis of symmetry of the core barrel (indicative of core twist off or core sand erosion during coring operations) is detected by a novel sensor combination. The sensor includes a reed switch mechanically imbedded in a support sleeve of a custom safety sub attached to the outer core barrel and electrically actuated by an adjacently positioned signature magnet fitted to the inner barrel to connect a power source uphole from the core barrels with a driver valve of a mud pulser system.During coring, circumferential passage of the reed switch adjacent to the signature magnet (during rotation of the outer core barrel to generate a core), allows the power source to periodically activate the valve driver to produce a series of mud pulses of constant repetition rate. But with the occurrence of rotation of the inner core barrel irregular repetition rates are produced at uphole indicating equipment.

Abstract: A perforating gun has a charge carrier assembly housed therein comprised of a plurality of charge holders connected together in tandem. Shaped charges are supported within each of the charge holders, such that the corresponding charges of each holder are circumferentially and vertically spaced apart from one another to forn a predetermined pattern. The individual charge holders describe a polyhedron whose bases or ends describe equal polygons, and whose lateral faces are rectangular and include a centrally located aperture which is adapted to receive a shaped charge in supported relationship therewithin.

Abstract: An improved small diameter, high density shaped charge perforating apparatus is provided. The perforating apparatus includes an elongated carrier member having a plurality of shaped charge receiving stations spirally located therealong. The anterior and dorsal sections of the shaped charges extend outside the outer diameter of the carrier member and a length of helically wound detonator cord passes through an axial aperture in the dorsal section to retain the shaped charges in the carrier member. An alignment member is connected to one end of the carrier member to prevent rotational movement of the carrier member within the gun body and aligns the axis of perforation for each shaped charge with spotfaces on recesses in the periphery of the gun body.

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 perforating gun for use in well bores and having a perforating means disposed in a azimuthal dispersion pattern about a vertical axis where the dispersion is characterized by azimuthal spacing of not less than 15.degree. with respect to each of the perforating means in a gun. The penetration pattern of the perforating means is dispersed longitudinally along the gun and rotatively around the circumference of the gun. The circumferential disposition of the shots can be in clockwise spiral or counterclockwise spiral or in a combination of spirals.

Abstract: A method and apparatus effecting the perforating of a well casing and the gravel packing of the perforated areas of the well casing of a combined perforating and gravel packing apparatus. This desirable objective is accomplished by a perforating gun construction permitting complete flexiblility to adjust in the field the number of horizontally and veritcally spaced shaped charges through the provision of a polygonal carrier having vertically spaced holes provided in each of its planar sides to accommodate vertically spaced horizontal groups of shaped charges with the charges in one horizontal group being angularly displaced relative to the charges in a vertically adjacent horizontal group. Additionally, the crossover mandrel employed in the gravel packing operation provides, in its run-in position, a continuous axial passage through its entire length, permitting a detonating device to be placed therethrough to actuate the perforating gun.

Abstract: A method and apparatus effecting the perforating of a well casing and the gravel packing of the perforated areas of the well casing with one trip into the well of a combined perforating and gravel packing apparatus. This desirable objective is accomplished by a perforating gun construction permitting complete flexibility to adjust in the field the number of horizontally and vertically spaced shaped charges through the provision of a polygonal carrier having vertically spaced holes provided in each of its planar sides to accommodate vertically spaced horizontal groups of shaped charges with the charges in one horizontal group being angularly displaced relative to the charges in a vertically adjacent horizontal group. Additionally, the crossover mandrel employed in the gravel packing operation provides, in its run-in position, a continuous axial passage through its entire length, permitting a detonating device to be placed therethrough to actuate the perforating gun.

Abstract: A perforating gun carrier comprising an inner substantially tubular housing within an outer substantially tubular sleeve. The inner housing includes gun ports extending through the wall thereof in a pattern corresponding to the pattern of shaped charges to be carried within. The sleeve may be secured to the housing by welding, soldering, brazing, adhesive bonding or other known method, may be shrink-fit onto the housing, or may be mechanically secured thereon.

Abstract: A method and apparatus are provided for angularly aligning normally vertical rows of explosive charge containers mounted on a tubing conveyed perforating gun carrier so that none of the explosive charges is directed substantially vertically upwardly in the event that perforation is accomplished in a non-vertical section of the well casing.

Abstract: A novel and improved form of through-tubing perforating assembly conformable for use in various types of cased well bores having particular application in those in which a tubing string is positioned within the cased well bore and where extremely high pressures are encountered at the bottom of the well. A plurality of shaped charges are mounted in a modular carrier comprised of a plurality of generally tubular members interconnected in end-to-end relation to one another, each tubular member having an internal cavity defining a horizontally directed seating portion for supporting one of the shaped charges therein. An end cap is disposed at the lower end of the modular carrier, and a blasting cord extends continuously through the tubular members across one end of the shaped charges for detonating the charges when positioned opposite to that part of the formation to be perforated.

Abstract: In accordance with the present invention, rotation of the inner barrel relative of the axis of symmetry of the core barrel (indicative of core twist off or core sand erosion during coring operations) is detected by a novel sensor combination comprising a battery-powered Hall-effect device fitted to the inner barrel imbedded in a support sleeve of a custom safety sub attached to the outer core barrel adjacent to a single signature magnet.During coring, circumferential passage of the Hall-effect device adjacent to the signature magnet (during rotation of the outer core barrel to generate a core), produces a series of signals of constant repetition rate. But with the occurrence of rotation of the inner core barrel irregular repetition intervals are produced at uphole indicating equipment connected to the Hall-effect device through conventional downhole telemetering and power generating equipment.

Abstract: In accordance with the present invention, rotation of the inner barrel relative of the axis of symmetry of the core barrel (indicative of core twist-off or core sand erosion during coring operations) is detected by a novel sensor combination comprising a Hall-effect device imbedded in a support sleeve of a custom safety sub attached to the outer core barrel adjacent to a single signature magnet fitted to and carried by a special support ring attached to the inner barrel. In releasably attaching the inner and outer core barrels together, the special support ring is made to be locking through operation of a series of compression strings acting between the lower surface of the ring and the inner core barrel as to wedge the upper surface of the support ring against an annular stopper ring. Result: the inner core barrel does not rotate relative to the outer core barrel during the trip down to the bottom of the well bore.

Abstract: A through the tubing perforating gun assembly having means for separating the upper head from the gun carrier upon firing. This allows the gun carrier to fall to the bottom of the well and eliminates the need to retrieve the carrier. Special charges are used to separate the carrier from the head with the charges being fired simultaneously with the gun charges.

Abstract: The apparatus comprises an elongated support (22) having a series of flat-faced portions and explosive charges (23) mounted perpendicular to the flat faces. Detonating cords are connected to the charges to fire them.Each portion of the support has two closely spaced attachment holes adapted to receive respectively the rear parts of the two charges mounted in opposite directions on each face of this section. The support is made up of a tube flattened transversely so as to form the flat-faced portions. Spacers are disposed between the charges and the support for casings of large diameter. The cases of the charges comprise a cover made of ceramic material and an extruded steel body which tends to flare out when the explosive is detonated rather than being broken into pieces.

Abstract: In accordance with the present invention, rotation of the inner barrel relative of the axis of symmetry of the core barrel (indicative of core twist off or core sand erosion during coring operations) is detected by a novel sensor combination comprising a Hall-effect device imbedded in a support sleeve of a custom safety sub attached to the outer core barrel adjacent to a signature magnet fitted to the inner barrel.During coring, circumferential passage of the Hall-effect device adjacent to the signature magnet (during rotation of the outer core barrel to generate a core), produces a series of signals of constant repetition rate. But with the occurrence of rotation of the inner core barrel irregular repetition rates are produced at uphole indicating equipment connected to the Hall-effect device through conventional downhole telemetering and power generating equipment. Result: sticking and jamming of the core can be immediately detected and uphole parameters modified to ease unsafe conditions.

Abstract: The invention provides a subterranean well casing perforating gun device which employs shaped explosive charges to perforate the well casing. The device generally defines an outer tubular housing assembly concentrically insertable in the well and defining a vertical axis, cylindrical chamber. A tubular carrier of polygonal cross sectional configuration is insertable in the chamber in concentric relationship to the cylindrical wall of the cylindrical chamber. Each of the faces of the carrier have a plurality of spaced passages therethrough, each passage having a configuration substantially corresponding to the configuration of the polygonal face. A shaped charge container has its cylindrical body insertable in any selected one of the passages and a radial flange on the outer end for abutting the polygonal face portion adjacent the respective passage, thereby limiting the insertion of each of the containers into the selected passage.

Abstract: In a perforating apparatus, a series of explosive charges are mounted on a frangible strap which is pressfit within a frangible carrier which is suspended from a conventional form of wire line tool in such a way that when the charges are detonated the carrier assembly will be completely disintegrated and the wire line tool can be retrieved for subsequent reuse.

Abstract: A device in core drilling for indicating when a core barrel placed in a rotatable hollow drill rod is no longer capable of receiving a further quantity of reamed-out core material includes a valve which at said condition of the barrel constricts the passage for flushing medium flowing between the core barrel and the bore of the drill rod so that a readable flushing medium pressure increase occurs. The valve closes off said passage incompletely to allow a minor quantity of flushing medium to be taken to the drill bit mounted at the bottom of the drill rod, thereby to prevent said drill bit from being burnt out.

Abstract: The detonating bore in the rear wall of a shaped charge case is outwardly convex. A powdered explosive is compacted into the case through the open front opposite the detonating bore, causing the portion which enters the convex end of the bore from within the case to be less compacted and less dense, for increased sensitivity and more reliable detonation.

Abstract: A borehole is formed down into the ground and extends towards an underlying pay zone, and then is turned horizontally through the pay zone, and then continues back up towards the surface of the earth; so that the resultant borehole is continuous from an inlet to an outlet, with the inlet and outlet being spaced from one another. When the free end of the drill string arrives at the outlet, one end of a casing string is attached thereto, and the casing string is pulled back through the entire borehole so that the borehole is cased from the outlet to the inlet, or vice versa. The casing is perforated adjacent to the pay zone so that the hydrocarbons may flow from the pay zone into the interior of the casing. Production is achieved through either of the spaced inlet or outlet; or, by using one vertical length of the borehole to force fluid to flow through the entire borehole, thereby forcing the production to the surface.

Abstract: In a perforating apparatus which has a plurality of explosive charges contained in an elongated tubular perforating gun body and supported on a carrier an energy absorber and explosive charge holder are provided by the present invention. The carrier extends longitudinally in the gun body and has the cases of the explosive charges mounted therethrough with a detonating cord or prima cord positioned at the detonating end portion of the several explosives charges. The energy absorber and explosive charge holder comprises a shaped metallic shield that grasps sides of an explosive charges case to secure it in a rigid fixed position on the carrier. An aperture in this shield permits passage of the detonating cord over the detonating end portion of the charge case and retention of it at that location.

Abstract: An integrated jet perforation and controlled propellant fracture device and method for enhancing production in oil or gas wells, wherein the device is inserted in a well bore to the level of a geological production structure; the fracturing device being constructed with a cylindrical housing of variable cross-section and wall-thickness with the housing filled with combustible propellant gas generating materials surrounding specially oriented and spaced shaped charges, having an abrasive material distributed within the propellant filled volume along the device length to produce enhanced perforations with attendant pressure-controlled gas and fluid injection into the perforations to produce controlled frac entry at point or points desired in the producing zones of the well bore, wherein a high velocity jet penetrates the production zone of the well bore initiating fractures, and is simultaneously followed by a high pressure propellant material which amplifies and propagates the jet initiated fractures.

Abstract: A shaped charge unit for well perforating having a outer shell with an internal cavity formed therein. An explosive charge material conforms in exterior shape with the inside surface of the cavity and is retained in place by a conical liner of non-explosive material. The interior shape of the cavity is such that an increased amount of explosive material is provided in a circumferential channel located proximate to the periphery of the base of the conical liner.

Abstract: A perforating unit for high density, multiphase well perforating operations having a plurality of elongate cylindrical perforating gun barrels whose firing axes are at predetermined angles one relative to the other. A multiport top sub secures the upper ends of the barrels with the barrels parallel to each other. A cablehead on the top sub provides for support. A multiport bottom sub secures the lower ends of the barrels. A circuit in the cablehead extends through the cablehead and into the unit for use in detonation of explosive charges to be received therein.

Abstract: A borehole is formed down into the ground and extends towards an underlying pay zone, and then is turned horizontally through the pay zone, and then continues back up towards the surface of the earth; so that the resultant borehole is continuous from an inlet to an outlet, with the inlet and outlet being spaced from one another. When the free end of the drill string arrives at the outlet, one end of a casing string is attached thereto, and the casing string is pulled back through the entire borehole so that the borehole is cased from the outlet to the inlet, or vice versa. The casing is perforated adjacent to the pay zone so that the hydrocarbons may flow from the pay zone into the interior of the casing. Production is achieved through either of the spaced inlet or outlet; or, by using one vertical length of the borehole to force fluid to flow through the entire borehole, thereby forcing the production to the surface.

Abstract: An improvement in an apparatus for fracturing subterranean formation by explosive fracture wherein opposed end charges are detonated to enhance the explosive capability of a central charge, the improvement comprising intermediate driver charges intermediate the central charge in each of the respective end charges; the driver charges being detonated by the end charges to provide a sustained pressure wave for enhancing the rubblizing and fracturing of the subterranean formation and extend the fracture more deeply into the subterranean formation. Also disclosed are improved apparatus enabling carrying out the split second detonating of the respective explosive charges, containing the explosive charges without entangling cable and the like downhole and preventing misfiring.

Abstract: A shaped charge retention and barrier clip according to the invention includes a barrier ring means for preventing damage to the interior of a perforating gun, and retention means for securing the barrier ring means and the shaped charge to a carrier strip disposed in the perforating gun.

Abstract: An explosive safe-arming system for use in a perforating gun for oil and gas well wireline operation is disclosed, wherein a donor detonating explosive is used which includes two encased elements. The first element is fixedly secured within the perforating gun, and the second element is removably mounted within the perforating gun.

Abstract: A mounting system for shaped charge explosive perforation of an oil well casing (24) includes an elongated support panel (28) having spaced apertures (44, 46) receiving cylindrical-conical shaped charges (26) retained by spring wire clips (30). The shaped charge (26) has an open mouth cylindrical portion (36) with a shoulder (52) at a reduction to the diameter of the apertures (44, 46), and a circumferential groove (54) spaced from the shoulder (52) a distance about equal to the thickness of the panel (28). The spring wire clip (30) has a semicircular portion (78) mating in the circumferential groove (54) for about 180.degree., and has oppositely directed radical extensions (70, 72) terminating in hooks (74, 76) which extend above the panel (28) to receive and position primer cord (32) seated in a transverse groove (62) in the apex (64) of the conical portion (34) of the shaped charge (26).

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: Apparatus for severing a conduit along a plane generally transverse to the axis of the conduit which includes two confined explosive charges aligned axially with the conduit and terminating at opposed proximal convexly shaped ends facing each other across a space disposed in such transverse plane. A liner formed of high density ductile material having radially increasing thickness is attached to each of the proximal ends of the charges and detonation devices are disposed at the distal ends of the charges for originating simultaneous detonation of the charges. Methods of severing conduits using the apparatus are also provided.

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: Disclosed is a method and apparatus for attaching shaped charge units into a well perforating gun. The shaped charge unit has an ear shaped extension having a cavity for receiving a wire in the perforating assembly. A second extension is positioned on the perforating charge unit having a threaded hole for containing a screw which may be advanced into tight engagement with the wire in the cavity of the first extension. This arrangement allows perforating units to be quickly added or taken out of a perforating gun assembly by adjustment of the screws through the threaded assemblies of the perforating charges.

Abstract: Disclosed herein is a powdered metal casing and an apparatus and method for making the powdered metal casing, which casing is useful for shaped explosive charges for perforating oil and gas wells.