Abstract: A downhole sub has a cylindrical body and a sealing device disposed about the cylindrical body. The cylindrical body has a first fluid chamber configured to store a hydraulic fluid, a second fluid chamber configured to store a liquid energetic material, a piston slidably disposed between the first fluid chamber and the second fluid chamber, and an ignition unit. The sealing device has two annular pistons and two annular sealing rings. The sub is loaded with the liquid energetic material and lowered into a well casing installed in the subterranean formation. A section of the well casing having a plurality of perforations is sealed. The liquid energetic material in the downhole sub is injected into the subterranean formation through the plurality of perforations in the well casing and is detonated using the ignition unit in the downhole sub.

Abstract: A method of perforating a wellbore is described herein. The method includes lowering a perforating wellbore tool into the wellbore proximate a formation to be perforated, anchoring the perforating wellbore tool by setting an anchoring tool, perforating the formation, creating a low pressure chamber in the perforating wellbore tool, and unsetting the anchoring tool after a time delay.

Abstract: A perforating apparatus incorporating a selective self-sealing material is disclosed for sealing exit holes in a wall of the apparatus resulting from perforation operations. The perforating apparatus traps debris produced during downhole perforation operations and prevents the debris from entering the wellbore which avoids the need for remedial operations to remove debris from the wellbore. The self-sealing material may be disposed within the perforating apparatus adjacent to an interior surface of the wall or the self-sealing material may be disposed outside the perforating apparatus adjacent to an exterior surface of the wall. The self-sealing material may include an expandable polymer material, a swelling elastomer, a rubber and combinations thereof.

Abstract: Apparatus and methods for selectively actuating sliding sleeves in sub members which are placed downhole in a wellbore, to open ports in such sub members to allow fracking of the wellbore, or to detonate explosive charges thereon for perforating a wellbore, or both. A simplified dart and sleeve is used which reduces machining operations on each. The dart is preferably provided with coupling means to permit a retrieval tool to be coupled thereto, which upon the retrieval tool being so coupled allows a bypass valve to operate to assist in withdrawing the dart from within the valve subs. Upward movement of the retrieval tool allows a wedge-shaped member to disengage the dart member from a corresponding sleeve to allow the dart to be withdrawn.

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: An inexpensive bullet-shaped plug is shown for use in a blasting hole containing water in the bottom thereof, which plug permits dry powder to be used above the waterline rather than more expensive wet powder. After the blasting holes are drilled, if water accumulates in the bottom thereof, the bullet-shaped plug with a center weight is dropped into the hole, which bullet-shaped plug floats on the water. Small rocks are dropped on top of the bullet-shaped plug causing upper tentacles to flare out to engage the wall of the blasting hole. Dry powder is then loaded into the blasting hole on top of the bullet-shaped plug. A cap is inserted a distance below the surface of the blasting hole. Thereafter, a series of similar blasting holes are blown at one time to create debris that can be removed or further processed.

Abstract: An inexpensive bullet-shaped plug is shown for use in a blasting hole containing water in the bottom thereof, which plug permits dry powder to be used above the waterline rather than more expensive wet powder. After the blasting holes are drilled, if water accumulates in the bottom thereof, the bullet-shaped plug with a center weight is dropped into the hole, which bullet-shaped plug floats on the water. Small rocks are dropped on top of the bullet-shaped plug causing upper tentacles to flare out to engage the wall of the blasting hole. Dry powder is then loaded into the blasting hole on top of the bullet-shaped plug. A cap is inserted a distance below the surface of the blasting hole. Thereafter, a series of similar blasting holes are blown at one time to create debris that can be removed or further processed.

Abstract: An electronic blasting capsule which includes a housing which contains a propellant, a fuse, a sensor for detecting the position of the housing in a capsule delivery path, an energy arrangement for obtaining energy from an external energy source, and a controller, responsive to the sensor and the energy arrangement, for firing the fuse to initiate the propellant.

Abstract: A borehole liner comprising a continuous length of polymer tubing of alternating diameters forming undulations sized for creating undulations in the liner to optimize the annular air gap alternating with full bore hole diameter loads of explosive to effectively reduce overall explosives consumption by 1-20%. Explosive charge weights can be modified to meet the users needs without introducing inert materials or other more labor intensive alternative.

Abstract: A buffering device for use in conjunction with a downhole tool string, wherein the tool string includes a ballistics device. The buffering device includes a mandrel attached within a tool string and proximate to the ballistics device. An anchor is disposed on the mandrel and a disk plate is coaxially placed on the mandrel that is slideable thereon. The disk plate is proximate to the ballistic device. A resilient member, such as a spring, is coaxially placed on the mandrel between the disk plate and the anchor. The pressure wave produced by activation of the ballistic device pushes the disk plate toward the anchor and compresses the spring there between. Since the disk plate extends outward into sealing contact with casing lining the wellbore, compression of the spring dissipates energy waves produced by activation of the ballistic device.

Abstract: Disclosed is a device and method for externally perforating a well-bore casing. The perforating apparatus is attached to the outside of the casing itself and is conveyed along with the casing when it is inserted into the well bore. The perforation is accomplished using two groups of charges which are contained in protective pressure chambers which are arranged radially around the outside of the wellbore casing. The pressure chambers form longitudinally extending ribs which conveniently serve to center the casing within the well bore. One group of charges is aimed inward in order to perforate the casing. A second group is aimed outward in order to perforate the formation. In an alternative embodiment, only one group of bi-directional charges is provided.

Abstract: Disclosed is a device and method for externally perforating a well-bore casing. The perforating apparatus is attached to the outside of the casing itself and is conveyed along with the casing when it is inserted into the well bore. The perforation is accomplished using two groups of charges which are contained in protective pressure chambers which are arranged radially around the outside of the wellbore casing. The pressure chambers form longitudinally extending ribs which conveniently serve to center the casing within the well bore. One group of charges is aimed inward in order to perforate the casing. A second group is aimed outward in order to perforate the formation. In an alternative embodiment, only one group of bi-directional charges is provided.

Abstract: A method and apparatus for placement of continuous pre-split, gel explosive in an elongated borehole or cavity. An anchor is attached to one end of a selected length of continuous gel explosive. A suitable anchor is a flexible, plastic “pilgrim's hat” with a hole in the narrow, closed end. The size of the anchor depends on the width of the borehole; the flared skirt should be narrow enough to permit insertion of the anchor into the hole but wide enough to resist removal. One end of the explosive charge is pressed through the hole in the anchor. The remainder of the length of explosive is placed inside a tubular member, such as PVC pipe. The loaded pipe then is inserted into the borehole or cavity with the anchor leading. The pipe is used to push the anchor back into the hole to the desired depth. Then, the pipe is withdrawn. The flexible skirt on the anchor engages the sidewall of the borehole and thus resists removal with the pipe.

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 shaped charge tubing cutter includes a minimal contact suspension to isolate the cutter explosive from the housing and sub structure. A charge detonation booster main-cavity is located on the juncture of the charge truncation planes. Explosive in the booster main-cavity is detonated by a shielded primer path. Explosive density in the primer path is less than the main-cavity density. A dense, powdered metal SC liner and an abruptly stepped jet window in the tubing cutter housing improve performance. The axial span of the jet window is preferably aligned with the axial span between the liner bases. A testing apparatus and procedure inexpensively verifies downhole performance.

Abstract: A tool (12) has a body (14) with a barrel (18) having opposing threaded and fitted openings (30 and 28). An actuator pin tube (26), for slidably engaging an actuator pin (38) having a tip (40) opposing a retention head (42), extending from the fitted opening (30). A spring assembly (24), disposed in the barrel (18), has a hammer guide (44) engaged in the threaded opening (28) with a hammer (46) slidably engaged therein, a handle mechanism (55) disposed at one end and a spring retainer (52) disposed adjacent the other end of the hammer (46) before a hammerhead (51), and a spring (54) engaged between the hammer guide (44) and the spring retainer (52). A release mechanism (56) engages the hammer (46). A kit (108) containing the tool (12) and a method of operating the tool (12) involving drilling and cleaning a borehole, inserting a cartridge and tool therein, and detonating the load remotely using a pull cord.

Abstract: Primer casing (1) comprising sleeve portion (5) and leading portion (5a), wherein sleeve portion (5) includes tabs (6) to retain primer (11) and blasthole engagement means (2), and wherein leading portion (5a) comprises nose cone (8). Engagement means (2) comprises an array of rigid, multiple projections that are hinged and movable between a retracted position and a blasthole engagement position. Explosive loading hose (13) locales within hose receiving sleeve (7) and can be used to push primer casing (1) into the desired location within the blasthole prior to filling the blasthole with bulk explosive. Methods of loading a blasthole comprising inserting primer (11) into primer casing (1) and positioning primer casing (1) at a desired location in a blasthole are also described and claimed.

Abstract: A novel method and device for sealing a borehole that is filled either partially or completely with water. A water-permeable sleeve is capable of expanding to the diameter of the borehole, and is constructed of a material that will allow the passage of water in and out throughout its length, with a series of apertures, but will prevent an explosive charge from escaping. Once the sleeve is in place, a hose, to introduce the explosive charge, is lowered through the sleeve to bottom of the borehole.

Abstract: A method and apparatus for placement of continuous pre-split, gel explosive in an elongated borehole or cavity. An anchor is attached to one end of a selected length of continuous gel explosive. A suitable anchor is a flexible, plastic “pilgrim's hat” with a hole in the narrow, closed end. The size of the anchor depends on the width of the borehole; the flared skirt should be narrow enough to permit insertion of the anchor into the hole but wide enough to resist removal. One end of the explosive charge is pressed through the hole in the anchor. The remainder of the length of explosive is placed inside a tubular member, such as PVC pipe. The loaded pipe then is inserted into the borehole or cavity with the anchor leading. The pipe is used to push the anchor back into the hole to the desired depth. Then, the pipe is withdrawn. The flexible skirt on the anchor engages the sidewall of the borehole and thus resists removal with the pipe.

Abstract: A method and apparatus for placement of continuous pre-split, gel explosive in an elongated borehole or cavity. An anchor is attached to one end of a selected length of continuous gel explosive. A suitable anchor is a flexible, plastic “pilgrim's hat” with a hole in the narrow, closed end. The size of the anchor depends on the width of the borehole; the flared skirt should be narrow enough to permit insertion of the anchor into the hole but wide enough to resist removal. One end of the explosive charge is pressed through the hole in the anchor. The remainder of the length of explosive is placed inside a tubular member, such as PVC pipe. The loaded pipe then is inserted into the borehole or cavity with the anchor leading. The pipe is used to push the anchor back into the hole to the desired depth. Then, the pipe is withdrawn. The flexible skirt on the anchor engages the sidewall of the borehole and thus resists removal with the pipe.

Abstract: A cartridge containing an explosive charge is inserted at the bottom of a short hole drilled in the rock. The cartridge is held in place or stemmed by a massive stemming bar of high-strength material such as steel. The cartridge incorporates additional internal volume designed to control the application of pressure in the bottom hole volume by the detonating explosive. The primary method by which the high-pressure gases are contained in the hole bottom until relieved by the opening up of controlled fractures, is by the massive inertial stemming bar which blocks the flow of gas up the drill hole except for a small leak path between the stemming bar and the drill hole walls. The stemming bar is preferably connected to a boom mounted on a carrier. A preferred embodiment incorporates an indexing mechanism to allow both a drill and a small-charge blasting apparatus to be used on the same boom for drilling and subsequent charge insertion and firing operations.

Abstract: A charge assembly for use in a cutter for splitting couplings used in joining together lengths of buried pipe is provided that allows several explosive charge segments to be used instead of a single explosive charge. The smaller explosive charge segments utilize less explosive material which complies with applicable shipping regulations. The charge assembly has an elongate charge housing with an open interior. At least two linear charge segments are longitudinally aligned in an abutting relationship with the other within the housing interior. The linear charge segments may be formed from an explosive core encased within a metal sheath. A pair of longitudinally spaced charge abutment members may be mounted within the housing interior, with the abutment members engaging the aligned charge segments at opposite ends. One of the abutment members includes a housing end closure.

Abstract: The present invention includes a small diameter explosive cartridge and a two-stage large diameter explosive cartridge apparatus for presplitting rock can be axially detonated by detonating cord through a central detonation passageway in the explosive cartridge while keeping the detonating cord and the explosive material in the explosive cartridge physically separate. The explosive cartridge includes an outer tube and an inner tube inside of the outer tube. The explosive cartridge includes two or more continuous webs extending radially between the outer surface of the inner tube and the inner surface of the outer tube. For the small diameter explosive cartridge, the space between the outer surface of the inner tube and the inner surface of the outer tube is filled with high explosive material such as water gel or emulsion explosive material.

Abstract: A rock breaker uses shotgun cartridges or other firearm ammunition as the explosive charge at the bottom of a drilled borehole. The breaker includes a heavy steel rod or bar, a gun with a firing chamber for the ammunition which screws onto the rod, a long firing pin running through a central passage in the rod, and a firing trigger mechanism at the external end of the bar which strikes the firing pin to fire the cartridge within the borehole. A tubular sleeve surround the main body of the rod and includes slits the end to allow it to expand. The rod has a conical taper at the internal end against which the end of the sleeve expands when the sleeve is forced along the rod toward the taper by a nut threaded onto the external end of the rod. As the sleeve end expands, it pushes against the borehole and holds the explosive gasses within, and also prevents the breaker from flying out of the borehole.

Abstract: A disposable point detachably mounted on the lower end of a vertically movable hole forming elongated member with the point having an explosive charge mounted therein in order for the disposable point and explosive charge to remain in the bottom of a hole formed by the elongated member and point when they are forced into a subsurface formation which is to be seismically explored with the elongated member then being retracted.

Abstract: A wet/dry explosive assembly for use with small diameter bore holes is disclosed. The device utilizes a small diameter watertight inner containment vessel to house a predetermined amount of blasting agent, such as ammonium nitrate with fuel oil (AN/FO). A rigid stiffener material surrounds the inner containment vessel and extends the length of an outer containment vessel. The outer containment vessel is of sufficient length and diameter to accommodate the inner containment vessel, the stiffener material and the blast detonation components necessary for proper detonation. The device is designed to accommodate bore holes of one inch (1") to three inches and one half (3.5") in diameter and up to one hundred feet (100') in length.

Abstract: There is disclosed, according to the present invention, an apparatus and method for loading explosives exhibiting little water resistance into water filled blast holes without contamination of the explosives by water. A pressure charger vessel, capable of being filled with bulk explosives of low density and low water resistance, such as ammonium nitrate fuel oil, is connected to a flexible plastic sleeve. A pneumatic plug fixedly connects the lower portion of the pressure charger vessel to the plastic sleeve. The plastic sleeve is lowered into a blast hole by means of a weight. Compressed air is then introduced into the pressure charge vessel and a valve means located between the sleeve and the pressure charger vessel is opened, permitting pressurized ammonium nitrate fuel oil to be pushed downwardly into the flexible plastic sleeve. Projections and recesses on the outer surface of the plastic sleeve facilitate the expulsion of water from the blast hole.

Abstract: In accordance with an illustrative embodiment of the present invention, a perforating gun apparatus for forming holes in a well casing through which cement can be circulated includes a mandrel, four arm-mounted, shaped charge carriers on the body, and bow springs on the body in the plane of each carrier for biasing the carriers outward into sliding contact with the well casing. The charges form evenly distributed series of vertically arranged holes the casing, without damage to an outer casing string, so that cement can be circulated through the holes and into the annulus without channeling.

Abstract: A hydraulically actuated firing head for a tubing conveyed well perforating system includes an actuating piston responsive to a differential between tubing pressure and a sealed low pressure zone contained within the firing head. The actuating piston releases a firing piston which initiates a firing sequence.

Abstract: An improved method for reducing misfires in large diameter unlined blastholes by fitting on the primer used in the blasthole a centering device comprised of a semi-conducting plastic material.

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: Apparatus for the pyrotechnic cutting of a submerged tube.The apparatus, which is introduced into the tube, comprises in a conventional manner a chassis on which is mounted a support for a pyrotechnic charge, a shield in the upper part of the chassis and a compressed air intake for producing an air pocket below the shield. According to the invention, the apparatus also comprises a ballast for facilitating its lowering to a considerable depth and the charge is a detonating cord with a hollow charge extending continuously over the support, the clearance between the charge and the inner wall of the tube being of minimum size and the same throughout.

Abstract: A barrier breaching device that is designed primarily for opening holes in interior walls of buildings uses detonating fuse for explosive force. The fuse acts as the ribs or spokes of an umbrella-like device that may be opened up to form a cone. The cone is placed against the wall so that detonating fuse that rings the base of the device and which is ignited by the spoke-like fuses serves to cut a circular hole in the wall.

Abstract: An improved process is provided for blasting in situ oil shale retorts, and oil and gas wells. In the process, a specially formed concrete plug is installed at a desired depth in a bottomless blast hole and an explosive charge is placed upon the plug and detonated to blast the underground formation. The plug is accurately and reliably set by lowering a canister, which releasably houses a bag support assembly supporting a bag of concrete slurry, to a desired depth into the blast hole. The bag support assembly and bag of wet concrete are subsequently dropped a fixed distance below the canister. The bag of concrete expands, dries, and hardens against the walls of the blast hole to form a permanent stationary plug across the blast hole. In the preferred process, the bag support assembly is formed by casting a concrete disc around a drainpipe, and the bag support assembly is lowered and released from the canister with the aid of an electrically powered sequencer.

Abstract: A plugging apparatus is provided to reliably plug a bottomless blast hole in underground oil shale retorts and oil and gas wells. The plugging apparatus has a special electrically powered sequencer which automatically lowers and releases a bag of cementatious slurry, supported by a drainpipe-reinforced concrete disc, from a canister to form a composite blasting plug in the blast hole.

Abstract: A tapping apparatus and method for making connections to pipelines and vessels while they are in service and contain fluid under pressure. The tapping apparatus and method includes an explosively driven punch that is operated to penetrate the pipeline. A tensile force is applied to retract the punch, and allow the fluid to pass from the pipeline through the apparatus and into the service connection.

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: An improved seismic explosive charge loader and anchor for loading and anchoring explosives in cylindrical containers in bore holes is disclosed, which includes a snap in spring band shaped anchor which effectively anchors the loader in the well bore against upward movement, one aspect of the invention includes a snap lock threaded connection for securing an explosive container having interrupted threads to the loader and anchor, and the loader and anchor is constructed and arranged to maintain a detonator in place in the explosive container thereby assuring detonation of the explosive.