Abstract: A fracking device (100) for generating shock waves in a well bore (102) comprises a fracking gun (110). The fracking gun (110) includes a cartridge (200) having a hollow cavity and a cylinder (202) disposed inside the hollow cavity of the cartridge (200). The cylinder (202) has a first chamber (210) and a second chamber (212). The first chamber (210) includes a plurality of explosive charges (206) positioned on an inner surface of the cylinder (202), wherein each of the explosive charges (206) contains an explosive mixture comprising hydrogen and stoichiometric oxygen in a predetermined ratio. The second chamber (212) contains a combustion-neutral gas. The first chamber (210) is separated from the second chamber (212) by a diaphragm (214).

Abstract: A system for a molded power charge with secondary pellet at each end. The molded power charge includes a solid outer wall which extends for the length. The solid outer wall has a first end and a second end. The power charge further includes a secondary pellet at each end. The first end and the second end of the outer wall include a secondary pellet with an exposed face. This allows the power charge to be ignited from either end.

Abstract: This application describes a device for stimulating a geologic formation using an electrically throttled liquid propellant. The device may be used for primary stimulation, changing the direction of a fracture in a wellbore during hydraulic fracturing, a re-frac of an existing interval to open new areas in an open interval, or reset fracture conductivity after extended shut in of the well. This comprises deploying the device on tubing or wireline and positioning it close to the selected wellbore interval where liquid propellant can be selectively ignited. The device's controls release and ignite an energetic material that produces expanding gas to increase pressure and stimulate the selected interval. The device is comprised of a reservoir to hold energetic material, a metering system to release propellant at a desired rate, an electrical ignition source to control output, a no backflow valve, and control module that operates the metering and electrical ignition.

Abstract: This disclosure provides a stackable propellant module for use inside of a gas generation canister. The modules are designed to enable them to be individually fired rather than as a unitary mass, as done in conventional configurations. This enables the generation of a controlled pressure profile rather than an uncontrolled pressure profile determined by the environmental conditions downhole, such as temperature and pressure.

Abstract: A tool for fracturing at least one tubular is described. The tool comprises a plurality of parallel columns of explosives and a detonation system configured to detonate the columns of explosives. The columns are arranged such that upon detonation, at least a portion of the Shockwave propagating in a direction outwardly from the tool from one column combines with at least a portion of the Shockwave propagating in a direction outwardly from the tool from another column to create a combined Shockwave of greater intensity than either of the Shockwaves which formed the combined Shockwave.

Abstract: This disclosure provides a stackable propellant module for use inside of a gas generation canister. The modules are designed to enable them to be individually fired rather than as a unitary mass, as done in conventional configurations. This enables the generation of a controlled pressure profile rather than an uncontrolled pressure profile determined by the environmental conditions downhole, such as temperature and pressure.

Abstract: An inflator (30) comprises at least one combustion chamber (34), filled with a plurality of solid propellant pellets (10), each of the solid propellant pellets (10) including a surface having a breaking point (19) which is delimited at least by two converging surfaces (28) produced by pressing. A method of manufacturing solid propellant pellets (10), includes the steps of providing a solid propellant (12), pressing the solid propellant (12) into a pellet blank (16), the pellet blank (16) having at least one predetermined breaking point (18) which divides the pellet blank (16) into at least two subareas (20), and breaking the pellet blank (16) along the at least one predetermined breaking point (18), wherein each of the at least two subareas (20) forms a solid propellant pellet (10).

Abstract: An explosive assembly includes a first explosive unit having a first longitudinal end portion having a first mechanical coupling feature, a second explosive unit having a second longitudinal end portion having a second mechanical coupling feature, and a tubular connector having a first end portion mechanically coupled to the first mechanical coupling feature and a second end portion mechanically coupled to the second mechanical coupling feature, such that the first explosive unit, the connector, and the second explosive unit are connected together end-to-end along a common longitudinal axis. Each explosive unit can contain a high explosive material and a detonator, and the connector can comprise a detonation control module electrically coupled to the detonators and configured to detonate the explosive units.

Abstract: Detonation control modules and detonation control circuits are provided herein. A trigger input signal can cause a detonation control module to trigger a detonator. A detonation control module can include a timing circuit, a light-producing diode such as a laser diode, an optically triggered diode, and a high-voltage capacitor. The trigger input signal can activate the timing circuit. The timing circuit can control activation of the light-producing diode. Activation of the light-producing diode illuminates and activates the optically triggered diode. The optically triggered diode can be coupled between the high-voltage capacitor and the detonator. Activation of the optically triggered diode causes a power pulse to be released from the high-voltage capacitor that triggers the detonator.

Abstract: Propellant structures and stimulation tools incorporating propellant structures may comprise composite propellant structures including two or more regions of propellant having different compositions, different grain structures, or both. An axially extending initiation bore containing an initiation element may extend through a center of the propellant structure, or may be laterally offset from the center. An offset initiation bore may be employed with a composite grain structure. Methods of tailoring ballistic characteristics of propellant burn to result in desired operational pressure pulse characteristics are also disclosed.

Abstract: A device for well stimulation comprising a carrying element (22) with a first delimiting element (23) and a second delimiting element (25), also at least one charge pack (30), which comprises one or more charge units (31) of a solid fuel, and also at least one detonator (40) for detonating the at least one charge pack (31), the charge pack or the charge packs being arranged on the carrying element (22) between the delimiting elements (23, 25), wherein the charge units (31) are configured as cylinders with a continuous axial clearance, and the carrying element (22) is formed as a rod or cable and is led through the axial clearances.

Abstract: An explosive assembly includes a first explosive unit having a first longitudinal end portion having a first mechanical coupling feature, a second explosive unit having a second longitudinal end portion having a second mechanical coupling feature, and a tubular connector having a first end portion mechanically coupled to the first mechanical coupling feature and a second end portion mechanically coupled to the second mechanical coupling feature, such that the first explosive unit, the connector, and the second explosive unit are connected together end-to-end along a common longitudinal axis. Each explosive unit can contain a high explosive material and a detonator, and the connector can comprise a detonation control module electrically coupled to the detonators and configured to detonate the explosive units.

Abstract: An auxiliary cartridge for use in rock breaking is disclosed which comprises an elongate body, an end closure at each end of the body and a charge of combustible material in the space defined by the body and the end closures. One of the end closures includes a frangible membrane which closes off a charge of combustible chemicals. On being subjected to the pressure of an external ignition of fast burning combustible material, the membrane fails and permits flame to flash through it from externally of the auxiliary cartridge to internally thereof thereby to ignite said charge.

Abstract: A coupling device which is configured such that respective explosives for blasting work are coupled to front and rear sections thereof. The coupling device includes cylindrical bodies, one of the bodies being movable away from or close to another one of the bodies, a partition provided inside a predetermined one of the bodies to divide an inner space of the predetermined body, and an expandable support section provided between the bodies to connect the bodies to each other. The expandable support section forms a cylindrical shape together with the bodies when one body is moved away from the other body and is radially expanded when one body is moved close to the other body. The explosives can be easily inserted into a blasting hole and be positioned in the center of the blasting hole, thereby increasing the efficiency of blasting work.

Abstract: A modular explosive breaching and demolition system comprised of inert light weight plastic assemblies, field custom hand packed or pre-loaded, utilizing for example cast-cure or press loaded explosives. The assemblies can be snapped together to make different geometeric shapes or lines as may be desired, for demolition objectives.

Abstract: A blasting cartridge comprising an elongated sleeve extending along an axis A and having a first end and a second end; the first end has a first sleeve closure with an opening for holding a detonator; the second end has a second sleeve closure; a space is provided between the first sleeve closure and the second sleeve closure for holding a blasting explosive; wherein the second end is provided with a connector means for releasably connecting the second end of the cartridge with a first end of an adjacent cartridge and comprising a firing pin means for impinging upon a detonator in the first end of the adjacent cartridge when the blasting explosive is detonated by actuation of the detonator in the first end of the cartridge.

Abstract: The present invention relates to apparatus and methods to stimulate subterranean production and injection wells, such as oil and gas wells, utilizing rocket propellants. Rapid production of high-pressure gas from controlled combustion of a propellant, during initial ignition and subsequent combustion, together with proper positioning of the energy source in relation to geologic formations, can be used to establish and maintain increased formation porosity and flow conditions with respect to the pay zone.

Abstract: A modular explosives cartridge comprises a tubular body having lockable coupling members secured on opposite ends thereof to form a bayonet coupling between opposite ends of respective cartridges to form an elongate tubular explosives cartridge. The lockable coupling members each include a sealing membrane to form a sealed closure at opposite ends of the tubular body, the sealing membranes being pierced during coupling to form a continuous column of explosive composition within said elongate tubular cartridge.

Abstract: A gas-generator is disclosed to intensify output of oil, gas, including gas from coal formations, or metals extracted by underground leaching by breakage and thermo gas chemical treatment of the critical formation zone with gaseous combustion products from a solid propellant. The rate of increase of gas pressure is raised and the effect on the formation is enhanced by assembling the gas generator using coated and bare charges in a selected ratio. The charges burn radially, so the coated charges, which burn only from the center outwards, burn for longer and with a rising output. A two-peaked pressure characteristic is thus obtained. A high-velocity igniter may also be used to give a third, early pressure peak.

Abstract: A proportional modular assembly of two charges for use in a gun, which charges are structured so that the power of one charge is related to the power of the other charge by a ratio of integers.

Abstract: An improved cast explosive charge and a method of manufacturing said cast explosive charges utilizing an automated assembly system. The explosive charges are produced by combining two elongate cast segments, thereby abutting an exterior surface of one segment, formed by explosive material into an exterior surface of a second segment formed by explosive material, and attaching the cast segments together with wrapping material. The cast explosive charge produced by this method of manufacturing exhibits a markedly improved detonation velocity.

Abstract: A detonation system especially useful for initiating a plurality of substantially simultaneous seismic detonations includes an electric trunkline circuit disposed on the surface of a firing site containing boreholes, within which booster charges having respective top and base portions are disposed. The booster charges are connected without intervening detonators to the downhole ends of equal-sized lengths of low-energy detonating cord, the surface ends of which are connected to semiconductor bridge-initiated electric detonators connected in series in the firing circuit. The resulting system, because of the small deviation in function time of the semiconductor bridge detonators, has greatly reduced scatter time as compared to prior art systems utilizing conventional downhole electric detonators, and has a safety advantage in that the boreholes are free of detonators.

Abstract: A system for initiating shock tube which has a low cost of manufacture, is relatively impervious to moisture, and initiates the shock tube reliably is described. The initiating system comprises a thermal input initiator device, a thermal enhancing output device, and a length of shock tube. The thermal input initiator device converts the thermal flame energy to percussive energy that travels as a signal wave along the shock tube at a speed of 6500 ft/sec. The signal wave hits the thermal enhancing output device and is converted back into thermal energy that is capable of reliably initiating display fireworks.

Abstract: The present invention is directed to a connector for transmission tubes wherein a first initiated transmission tube transfers a signal to a second transmission tube within said connector.

Abstract: A packaging system for explosives having a thin walled water resistent tube containing a low-sensitivity explosive therein. A first cap is fitted about one end of the tube and has a re-entrant portion that projects into the tube about which the explosive material is filled. The other end of the tube is sealed with a second cap to create a substantially water-tight explosive package. An initiator is received within an open-ended cavity formed in the re-entrant portion of the first cap and is detonated for setting off the explosive charge.

Abstract: A coupling device (10) for coupling a detonator cap (20) with an unfixtured detonating cord (80, FIG. 3 ) after removing a shipping plug (41, FIG. 2 ), features a sleeve member (12) having a longitudinal sleeve bore (18) extending therethrough for receiving a detonator cap (20) therein. The detonator cap (20) extends to the transition end (22) of the sleeve member (12) so that the detonating cord (80) does not enter the sleeve bore (18). A nut member (14) has an aperture (24) for receiving the cord (80) and is secured to the sleeve member (12) with its aperture (24) aligned with the bore (18). A ferrule (16) is seated on the sleeve member (12) and grips the detonating cord (80) when the nut member (14) is secured onto the sleeve member (12).

Abstract: A modular propellant charge (10) composed of N propellant charge modules (1; 11-16) each having a length Lo. In order to obtain an economical, durable, easily released connection between the propellant charge modules (1; 11-16), a displaceable sleeve (6; 17-22) of a length L is axially slidably arranged on the exterior of each propellant charge module (1; 11-16) with the relationship ##EQU1## applying for the length L. The displaceable sleeves are utilized to interconnect adjacent modules.

Abstract: An explosive diode transfer system is interconnected between adjacent perforating guns of a modular perforating apparatus. The explosive diode transfer system includes a downwardly directed shaped charge, a booster, and a multi-density barrier interposed between the shaped charge and the booster. The multi-density barrier includes a first metal layer and a second metal layer spaced from the first metal layer thereby defining a sealed air-space between the first and second metal layers. The first metal layer, air space, second metal layer combination represents a plurality of different density barriers or layers which are collectively designed to prevent a first detonation wave, propagating from the booster to the shaped charge, from propagating therethrough, but nevertheless to allow a jet, propagating from the shaped charge to the booster, to propagate therethrough.

Abstract: The field of invention is containers able to receive a propellant charge. A container (1, 12, 13) according to the invention, which is designed to be joined to another container at one of its end faces is characterized by the joining means having on the one hand a ring disposed on a constricted area provided at one end of the container, the ring being slidable axially to cover a second constricted area provided on the other container, and on the other hand having hooking device disposed on at least one of the container and the other container at the end faces designed to come in contact with each other.

Abstract: A mine assembly comprises at least one charge module having a cylindrical shape, and an upper and lower circular surface end. An activating module for detonating the at least one charge module is operatively connected thereto. The activating module has at least a lower cylindrical end and interconnecting means provided at the upper circular end of the charge module. The interconnecting means includes a ring-shaped element having an inner diameter which corresponds to an outer diameter of the lower end of the activating module and to a diameter of other charge modules. The ring-shaped element forms an upwardly extending projection along the circular upper end surface of the charge module to provide a space thereon adapted for receiving a cylindrical end of one of the modules.

Abstract: The invention provides a connector, a transmitter, a bi-directional device, and a method for increasing the reliability of borehole detonation by using the connectors and transmitters provided by the invention. The invention provides connectors, each connector having a well for receiving a blasting cap, one or more ports or channels for receiving a transmission line and/or downline, and means for joining one connector with another connector in a convenient manner. The connectors are constructed so that detonation of a blasting cap in one connector will cause sympathetic detonation of a blasting cap in an adjoining connector. The detonation of blasting caps in the connectors also causes initiation of transmission lines and/or downlines which are inserted in the ports or channels through the connectors.

Abstract: An ignition transfer body for a propellant-charge module is coaxially surrounded by a supporting tube and includes at least one clear ignition channel. The ignition transfer charge is composed of a first propellant-charge powder generating thermal energy in a range of 3 kJ/g to 4.5 kJ/g, and the supporting tube is composed of a second propellant-charge powder. Preferably, the second propellant-charge powder forming the supporting tube is pressed powder which is extruded or pressed in a mold.

Abstract: A downhole seismic acoustical signal source capable of selectively firing numerous, prewired explosive charges. The downhole seismic source uses a self-contained firing circuit that is capable of receiving select and fire signals from a seismic crew at the ground surface through a standard seven conductor wireline cable to detonate the explosive charges. The downhole seismic source is capable of generating numerous signals in a given downhole trip through the firing of many individual explosive charges.

Abstract: A high energy gas fracturing tool for radially fracturing a rock formation in a well bore consisting of a cylindrical canister that is holed to pass gas and is for housing a stack of propellant modules that are selected to provide a desired burn rate when ignited. Each propellant module mating face is angled from the horizontal between forty-five (45) to seventy-five (75) degrees, and the modules are bonded together with an epoxy resin wherein propellant or explosive particles are mixed, the resin to exhibit burn characteristics similar to those of the propellant stack. The tool, additional to the propellant containing canister, an ignitor rod and explosive device for igniting the propellant stack, mounts a bull head end over a lower end and a reverse thruster assembly that is connected to the canister upper end.

Abstract: A pre-packaged explosive charge of the type made up of modules having a threaded male coupling end and a threaded female coupling end is loaded into a bore hole by use of a plug fitting threadably attachable to the uppermost charge module. The fitting is constructed so that the torque required for disconnection of the fitting from the module is substantially less than the torque required to separate one module from another.

Abstract: A method and system for selecting and arming each one of a plurality of firing modules in a single-line selective perforating system is disclosed. A single firing line connects each firing module one at a time in a sequence to a control unit to receive power and control signals therefrom. Each module generates internally a module active time interval in response to being connected to the firing line power. Each time interval has a first portion during which the module generates an identification pulse to the control unit to indicate that another module has been connected to the firing line, and a second portion during which the module is enabled to receive a selection pulse from the control unit to terminate further sequencing of the modules to locate the module to be selected. The next module to receive power from the control unit is connected to the firing line by a pass-thru switch in the last connected module at the end of its active time interval if that module was not selected for firing.

Abstract: A booster container is used to hold a primary charge useful for detonating cap insensitive explosives, such as ammonium nitrate. The container includes a pair of cord tunnels which may be used in various combinations to detonate the primary charge with either an electric blasting cap or a detonating cord. The container is also useful for holding non-electric blasting caps and transfer tubes in place as the booster container is lowered into the bore hole.

Abstract: In a blow-molded, cylindrical plastic container for explosives adapted for end-to-end coupling with like containers, an improvement is provided in the sealing of the container at the exposed explosives end. The improvement comprises a section of reduced diameter in the portion of the container immediately beyond the point of connection of a like container. The section of reduced diameter is adapted to receive therein a resilient plastic, disc-like sealing member in fluid-tight engagement. The seal prevents contamination of the explosive yet yields upon the pressure exerted by an adjacent, connected container.

Abstract: A distributed charge for use in producing a very sharp impulse for seismic prospecting comprises a series of lump explosive charges placed preferably of the order of at least 20 feet apart in a fluid in a well, connected with novel timed fuses. These fuses are each made of a short top section of a small diameter detonating linear explosive and a considerably longer, lower section which is a non-detonating linear deflagrator, terminating in a blasting cap inserted in the next lower lump explosive charge. The lower section is in the form of a thin-walled plastic tube lined with the active chemical agent. It may be crumpled or bent into various shapes including crossovers without serious problems of disconnection or premature initiation. Accordingly, axial length of each such fuse may be considerably more than the physical distance between the lump explosive charges.

Abstract: An explosives package is disclosed comprising a plastic tubular container having male and female ends adapted to be coupled with like containers to form a column, and primer and blasting explosives contained therein. The container is open at both ends and has an internal circumferential ring seat. The ring seat and open end of the container enables a cast primer composition to be poured through the open end onto a piston which is in fluid-tight relationship with the ring seat. A capwell thimble is inserted into and retained in the side of the male end of the container so that the closed end of the capwell is situated within the cast primer composition.

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 linear explosive charge with constant detonation velocity comprising, a plurality of separate similar sticks that can be axially coupled into a long linear substantially rigid assembly. Each of the sticks includes a helical winding of linear explosive cord on its outer surface, the ends of the cord are coupled to the ends of the cord on adjacent sticks, so as to carry the detonation of the cord from one stick to the next. Separate booster explosive charge units are coupled into each of the junctions between sticks, to provide additional explosive units which are synchronously detonated by the passage of the cord detonation from stick to stick.