Abstract: The invention relates to an apparatus for severing tubular members and is provided with a carrier, which carries a sparging assembly and an explosive assembly downwardly into the tubular member to be severed. The outlet of the sparging assembly is below the lower end of the carrier and is at a level adjacent to the level of the explosive charge carried by the explosive assembly. The sparging assembly dislodges and agitates the debris accumulated within the tubular member and evacuates it from the level, wherein it is deployed, simultaneously allowing progression of the explosive assembly downward along the interior of the tubular member.

Abstract: A method of charging waterlogged boreholes with water-resistant particulate explosive material, comprises inserting a pneumatic line with upwardly directed nozzles at the lower end thereof and a material supply line into a borehole, blowing compressed air through the pneumatic line such that at least a portion thereof is directed through the nozzles to form a substantially water-free air pocket around the lower end of the supply line, supplying particulate explosive material through the supply line to a charging zone in the vicinity of the lower end thereof, and gradually withdrawing said line as the borehole fills up with explosive material.

Abstract: In the preferred embodiment of the new and improved perforating apparantus that is described herein, a set of end closure members are cooperatively arranged to be inserted into the open ends of a length of typical piping and expanded radially outwardly into contact with the rough and irregular internal wall surface in each end of the pipe. Anchor members and sealing members are arranged on each and closure member for releasably securing and sealingly engaging these end closure members in the ends of the pipe when the end closure members are respectively expanded outwardly so that no machining operations are required to prepare the internal wall surfaces of the pipe before it can be employed as an expendable perforating carrier.

Abstract: The invention provides a process for converting subterraneous ore overlain by an adjacent formation of porous rock into an enclosed zone of fragmented ore by first blasting a void space in the porous rock and secondly explosively expanding the ore into the void space. The invention also provides a process for the extraction and recovery of values from a subterraneous ore overlain by an adjacent formation of porous rock. The invention is particularly useful for the extraction and recovery of carbonaceous values from subterraneous oil shale.

Abstract: An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

Abstract: A rock breaking method includes drilling a hole in rock, filling the hole with water, inserting a short barrel of a rock breaking tool into the hole entrance, covering the tool with a recoil restraining mat, and discharging a cartridge down the barrel.

Abstract: The method of breaking rock by blasting comprises drilling of boreholes, loading of a blasting charge with a means of initiation therein and stemming. The stemming is made up of a phlegmatized low-velocity explosive.

Abstract: A metal tube is expanded by means of an explosive charge into engagement with a surrounding tubular metal member which is supported externally by a surrounding metal die member spaced from the metal member, the intervening space being filled with a shock transmitting liquid such as water. The metal die member is readily separated from the expanded tube and is reusable indefinitely without maintenance. Its use is therefore more economical than the split die hitherto used. The method is especially useful for expanding large diameter tubes, for example expanding oil-well drill pipes into pipe coupling members.

Abstract: The invention relates to a rock breaking tool having a barrel insertable into a pre-drilled, water-filled hole of the rock. The rock breaking tool utilizes a firing chamber to discharge a cartridge into the barrel. A blast absorbing mat is located over the tool to retain the tool in position in the hole during discharge. The invention also relates to the method of using the rock breaking tool.

Abstract: An expansive demolition agent prepared by crushing a clinker for manufacturing powdered expansive demolition agent obtained by sintering, which is capable of hydrating and expanding in a hole drilled in a brittle material to demolish the brittle material, the maximum particle diameter of the agent being one-third or less the diameter of the hole, and containing 10% or less of fine particles having a particle diameter of 0.3 mm or less.

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: The invention relates to an apparatus for explosively severing tubular members at a pre-designated severance level. The apparatus is designed to deliver a detonation signal to a ring-shaped explosive charge, to an annularly formed detonation signal receiving locations, so that explosion takes place substantially simultaneously about the circumference of the explosive charge about internal periphery of the tubular member at the severance level.

Abstract: A method for the electrical sequential initiation of explosions in which a series of detonators (D1-D11) is located in association with a series of explosive charges spaced from one another and in which a shot initiator 12 is used sequentially to initiate firing of the detonators at selected intervals to detonate the explosive charges, characterized in that each detonator is fired without the provision of a delay between the initiation of firing of the detonator at the shot initiator and the actual commencement of firing of the detonator, further characterized in that the interval between the firing of successive detonators is selected from a range of 5 ms to 40 ms.

Abstract: A method for carrying out wire bolting for bolting a rock, in which method drill holes are drilled in the rock through an ore body, and a wire is pushed into the holes. In order that the wires would not hamper the emptying of the ore body, the wire is weakened before it is passed into the hole at least at one point in such a manner that the wire breaks at the weakened point when the ore is blasted.

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 method of sinking shafts comprising excavating a series of lifts wherein each lift is excavated by drilling a pattern of blast holes for the full depth of the lift including boring a large diameter hole and creating a chamber at the lower end of the large diameter hole, blasting the walls of the chamber to deposit rock material into the chamber, extracting at least a portion of the rock material created by the blast and repeating the blasting and extraction step throughout the length of the lift wherein on the volume of said lift being blasted the remaining rock broken material is extracted.

Abstract: A method of smooth wall rock blasting is provided in which an alignment of boreholes for explosive charging is drilled into rock and a single, smaller diameter empty borehole is drilled close and parallel to, and on each side of each charged borehole. Upon detonation of the charged boreholes, the rock is cracked smoothly along the plane coincident with the axes of the holes. The method reduces drilling costs to a minimum and provides improved results over the previous pre-shearing and other known methods.

Abstract: A subterranean formation containing oil shale is prepared for in situ retorting by forming a fragmented permeable mass of formation particles containing oil shale in an in situ retort site. The retort is formed by excavating a lower level drift adjacent a lower portion of the retort site and excavating an upper level void adjacent an upper portion of the retort site. An undercut is excavated below a zone of unfragmented formation remaining within the retort site above the lower level drift. The undercut can be free of roof-supporting pillars. Explosive is loaded in the zone of formation from access provided by the upper void, and the zone of formation is blasted downwardly toward the undercut for forming the fragmented mass. The volume of the void space within the undercut prior to explosive expansion is similar to the void volume within the principal portion of the fragmented mass being formed.

Abstract: The method is especially useful for producing rock caverns for the storage of liquids such as water and oil. The method includes intersection blasting in accordance with the sublevel stopping method for at least one drift near the bottom of the intended rock cavern to produce at least one upwardly widening part section of the cavern. The cavern is then formed to its final cross-section by excavating rock above the part section through successive drilling and blasting of rock layers. The last-mentioned drilling is fan-shaped downwardly directed drilling to obtain an essentially lentiform cross-section of the cavern above the part section.

Abstract: The method produces an elongated rock cavern tunnel, or shaft, preferably with a large cross-sectional area. At least one drilling drift is first driven in the longitudinal direction of the cavern. From that drilling drift first drill holes are drilled in successive planes extending transversely to the longitudinal axis of the intended cavern. Charging and blasting is carried out in the first drill holes for excavating the cavern layer by layer.The first drill holes are drilled in an essentially ring or fan-shaped pattern and partially outside the intended contour of the cavern. Rock strengthening means is inserted beyond the contour in the drill holes prior to blasting so that the cavern walls and roof have such a degree of stability that work for reinforcing the walls and roof subsequent to blasting can be carried out within the cavern, or that the cavern can be used for its intended purpose, for example for storing liquids, without any further reinforcement following the removal of the blasted rock.

Abstract: The horizontal orientation of a rocket moving in a liquid is achieved by an arrangement in which a magnet is attached to the rocket body. The axis of the rocket and the magnetic axis of the magnet form an azimuthal angle .alpha., which determines the direction of the rocket relative to the geomagnetic meridian.

Abstract: A charging apparatus includes a charging hose, one end part of which is arranged to be connected to at least one supply of particulate or liquid explosive, and the other end part of which is arranged to be inserted into a drill hole to deliver thereto explosive fed through the charging hose from the forementioned supply; a guide sleeve for guiding the charging hose; a hose-feeder arrangement for displacing the charging hose longitudinally in the guide sleeve; and an aligning and adjusting means for carrying the guide sleeve and placing the aforementioned one end of the sleeve in a position for guiding the other end part of the charging hose into the drill hole. The wall of the guide sleeve is provided with a closeable opening arranged to enable bodies of solid explosive or cartridged explosive to be introduced into the guide sleeve when the charging hose is at least partially withdrawn out of the guide sleeve.

Abstract: To prevent the rapid escape of high-pressure explosion gases when an explosive charge is initiated in a borehole, the hole is stemmed with chunks of readily liquefiable and/or vaporizable solid material, preferably chunks of ice and/or chunks of dry ice, piled up one upon the other so as to form a columnar bed of pre-solidified stemming material. The column remains in place during the explosion, and thereafter disappears by melting and/or subliming on absorbing heat from the surrounding formation. A preferred stemming column comprises a combination of ice chunks and chunks of dry ice, e.g., wherein the ratio of dry ice to ice in the column decreases with distance from the explosive charge.

Abstract: An in situ oil shale retort is formed in a retort site in a subterranean formation containing oil shale. The in situ retort contains a fragmented permeable mass of formation particles containing oil shale within top, bottom and generally vertically extending side boundaries of unfragmented formation. Formation is excavated to form at least one void in the subterranean formation while leaving zones of unfragmented formation above and below such a void and at least one support pillar of unfragmented formation in the void. Such a pillar of unfragmented formation extends between the zones of unfragmented formation above and below the void and is explosively expanded by use of techniques which minimize shock damage to the zones of unfragmented formation. The techniques, which can be used individually or in various combinations, include placing explosive charges into the top, bottom and middle portions of the pillar.

Abstract: A method for forming an in situ oil shale retort in a subterranean formation containing oil shale is provided. The in situ retort contains a fragmented permeable mass of formation particles within top, bottom, and generally vertically extending side boundaries of unfragmented formation. A lower portion of the fragmented permeable mass of formation particles having a nonlevel top surface is initially formed in the retort. A void space is left within the retort boundaries extending between the nonlevel top surface of the fragmented mass lower portion and a generally horizontally extending free face of an overlying layer of unfragmented formation. Thereafter, the overlying layer of unfragmented formation is explosively expanded into the void space to thereby form the remaining portion of the fragmented mass in the retort. The overlying layer is expanded in a plurality of separate horizontally spaced regions with a time delay between explosive expansion of each successive region.

Abstract: An in situ oil shale retort containing a fragmented permeable mass of formation particles having a generally uniform permeability across horizontal cross-sections of the retort is provided. To form the retort, underground formation is explosively expanded by explosive charges placed in a selected pattern. The combination of spacing distance and powder factor of central explosive charges is selected to produce a center portion of the fragmented permeable mass having a first average particle size (d.sub.1) and a first average void fraction (e.sub.1). The powder factor for perimeter explosive charges and the spacing distance between central charges and adjacent perimeter charges are selected to produce a perimeter portion of the fragmented permeable mass having a second particle size (d.sub.2) and a second void fraction (e.sub.2). The second average particle size (d.sub.2) and the second average void fraction (e.sub.2) are related to the first average particle size (d.sub.

Abstract: A method that produces a uniformly rubblized oil shale bed of desirable porosity for underground, in-situ heat extraction of oil. Rubblization is the generation of rubble of various sized fragments. The method uses explosive loadings lying at different levels in adjacent holes and detonation of the explosives at different levels in sequence to achieve the fracturing and the subsequent expansion of the fractured oil shale into excavated rooms both above and below the hole pattern.

Abstract: Apparatus and method for digging deep trenches having parallel generally vertical walls in solid rock such as limestone. The apparatus includes a transport means for providing support and for moving along a traverse on the earth's surface while cutting a trench along that traverse. The transport carries a boom which may be articulated into the ditch being cut and a pair of rock cutterwheels carried on the end of the boom and assembled so that the outermost cutter teeth are wider than any other part of the boom assembly. The apparatus further includes means for aligning the flat surfaces of the rock cutter wheels parallel to and between the walls of the ditch and for maintaining alignment of the wheels with the trench as the transport moves along the traverse so that repeated cuts may be made to extend the trench to any desired depth.

Abstract: An in situ oil shale retort containing a fragmented permeable mass of formation particles having a generally uniform permeability across horizontal cross-sections of the retort is provided. To form the retort, a void is excavated in a subterranean formation within the boundaries of the retort site, while at least one zone of unfragmented formation is left adjacent the void. A plurality of explosive charges are placed in the zone of unfragmented formation in a selected pattern; an array of central explosive charges and a plurality of perimeter charges arranged in rows surrounding the central charges. The spacing distance between each row of perimeter charges and an adjacent outer row of central charges is about equal. The combination of spacing distance and powder factor of the central charges is selected to produce a center portion of the fragmented permeable mass having a first average particle size (d.sub.1) and a first average void fraction (e.sub.1).

Abstract: A two-piece, telescopic climber, which is insertable into a drillhole behind cylindrically shaped explosive charges, alternately advances one and then the other of its two telescopic pieces in the direction of the drill hole thereby to urge the charges forwardly thereof into the hole. Each piece has thereon means which expands outwardly against the wall of the drill hole to hold that piece stationary while the other piece advances. At least one of the two pieces can be removed from the drill hole to be used repeatedly.

Abstract: A method of charging upwardly extending, large diameter boreholes with cylindrical explosive cartridges is provided employing a longitudinally inflating flexible tube as the pushing mechanism. A fluid-impervious flexible tube is turned over or everted at one end and secured. A fluid, preferably air, at about 3 psi is passed into the tube causing the tube to elongate and the everted tube face to travel along the length of a borehole. An explosive cartridge mounted against the tube face is carried to a desired location in the borehole after which the tube is partly deflated and withdrawn from the borehole.

Abstract: A method of reducing a highwall or sharp cliff like exposure at a mining site to gradable rubble for the purpose of reclamation is disclosed. The method includes the steps of placing a series of non-directional explosive charges at specific preselected locations on the floor of cavities created by mining, such cavities being auger holes, longwall mine areas or the like. The charges are then detonated within the cavities to create rubble. Preferably, each cavity is sealed proximate its opening on the highwall with stemming to maintain pressure within the associated cavity during the blast and to alternate the expulsion of air blast emissions. The charges are detonated to attenuate the horizontal force vectors, and to enhance the vertical force vectors such that the major effect of the blasts is exerted on the overburden to assure breakage. An improved charge for carrying out the method of the present invention is also disclosed.

Abstract: The present invention comprises a high-density perforating gun in which the shaped charges carried thereby are oriented so that the jets emanating therefrom substantially intersect the axis of the gun. The shaped charges may be vertically spaced by a distance less than the diameter of the charges, but sufficient for each charge jet to pass unobstructed by other jets emanating from the charges immediately above and below.

Abstract: A method for loading explosive charges into blastholes in a subterranean formation for forming a fragmented permeable mass of formation particles in an underground cavity in the formation is provided. Upper and lower voids spaced apart vertically from each other by unfragmented formation are excavated into the subterranean formation. A generally vertical blasthole is formed in the unfragmented formation between the voids. Upper and lower explosive charges, separated from one another by stemming, are formed in the blasthole. Each such explosive charge includes at least one primer operationally connected to an explosive initiating lead that extends from the charge. The explosive initiating lead of the upper explosive charge extends from the top of the blasthole into the upper void and the explosive initiating lead of the lower explosive charge extends from the bottom of the blasthole into the lower void.

Abstract: This system develops an ore body in two lifts, driven from opposite ends (at different times) and utilizes the concept of lane pillars rather than square block pillars. These conditions generate a new ventilation system that is flexible and well suited for the varying air requirements in oil shale mining.The ore handling system is load-haul-dump (LHD) to portable crushers to belts to surface. The layout of this method introduces unique functions for this system by creating two directional ore flow from the workings, which optimize logistics and material handling methods.

Abstract: An explosive charging apparatus for charging controlled amount of explosives sequentially to bores drilled in a rock surface. The charging apparatus includes an explosive charging pipe, a boom mechanism carrying the explosive charging pipe, boom actuators for actuating the boom mechanism so that the explosive charging pipe is moved to a desired position, a control circuit for controlling the boom actuators and the explosive charging pipe.

Abstract: This invention relates to an automatically controlled rock drilling apparatus which performs rock drilling operations as well as post-drilling operations such as explosive charging. Memory means are used during the drilling operation and reused during subsequent operations for follow-up work, specifically the charging of explosive to the drilled bores.

Abstract: Steep dip strong-coal deposits can be broken in an explosive mine environment utilizing a succession of explosive units each of which comprises a core tube surrounded by a body of explosive material which, in turn, is surrounded by an arc-suppressing heat-dissipating fluid. Igniters in the explosive charges have conductors which are lead back out of the bore hole through the tubes of the explosive units which are anchored at spaced locations along the bore hole.

Abstract: A method for controlling the average particle size of a fragmented permeable mass of formation particles formed in an in situ retort in a subterranean formation containing oil shale is provided. At least one void is excavated in the subterranean formation, leaving zones of unfragmented formation above and below the void. Such a zone of unfragmented formation has naturally occurring cleavage planes and a substantially horizontal free face adjoining the void. An array of a plurality of substantially vertical blastholes is formed in at least one of the zones of unfragmented formation and each such blasthole is loaded with explosive for forming a substantially horizontal array of explosive charges. The spacing distance between adjacent blastholes or explosive charges in the array is from about 10 to about 15 times the average distance between cleavage planes when the oil shale formation has an average grade of more than about 20 gallons per ton.

Abstract: The invention provides a container for explosive material comprising a rigid tube (10 FIGS. 1-4, 18 FIGS. 5-8) a closure (13,14; 19,20) at each end of the tube, said tube having a recess (12; 21) in its wall between its ends to receive a detonating cartridge.

Abstract: Cartridge for bulling mine holes, which is of cylindrical shape, is made of n elastic material and possesses a zone 7 capable of deforming axially and a zone 6 capable of deforming radially, under the effect of an axial or radial pressure exerted on the cartridge or under the effect of an internal pressure variation, in which cartridge the volume of the zone 7 capable of deforming axially is greater than the volume of the zone 6 capable of deforming radially.

Abstract: A method for forming an in situ oil shale retort in a retort site in a subterranean formation containing oil shale and having at least one set of naturally occurring cleavage planes is provided. The in situ oil shale retort contains a fragmented permeable mass of formation particles formed within top, bottom, and side boundaries of unfragmented formation. A void is excavated in the subterranean formation within the boundaries of the retort site, while a zone of unfragmented formation is left within the retort boundaries adjacent the void. A plurality of rows of horizontally spaced apart explosive charges is formed in the zone of unfragmented formation where each such row is in a line about perpendicular to the strike of the major cleavage plane set in the formation.

Abstract: A subterranean formation containing oil shale is prepared for in situ retorting by forming a fragmented permeable mass of formation particles containing oil shale in an in situ retort site. The retort is formed by excavating a lower level drift adjacent to a lower portion of the retort site and excavating an undercut within the retort site below a zone of unfragmented formation remaining within the retort site above the undercut. The bottom of the undercut slopes downwardly toward the lower level drift which opens into one side of the undercut, the slope being generally at the natural angle of slide of oil shale particles. The remaining zone of unfragmented formation is blasted downwardly toward the undercut in a series of lifts in sequence progressing upwardly in the retort site. The mass of formation particles formed during such blasting in lifts tends to slope downwardly toward the side of the retort adjacent the lower level drift.

Abstract: Following the conventional mining of rich oil shale for conventional above ground retorting, by horizontally extensive room and pillar mining operations, additional shale oil and related product may be secondarily recovered from the oil shale formation by in-situ retort formation and combustion. The secondary recovery steps would involve initially the identification of a large horizontally extending area, normally located between barrier pillars, which may be blocked off for the in-situ retort. Suitable shale oil drain arrangements may then be provided along one lower edge of this in-situ retorting area. Along the opposite lower edge of the in-situ retorting area, conduits may be provided for withdrawing product gas from the retort area. The retort area may then be sealed, and rubblized by blasting the pillars and caving in the roof to provide the appropriate 15% to 30% void volume for in-situ retorting.

Abstract: An in situ oil shale retort is formed in a subterranean formation containing oil shale by excavating one or more horizontally extending voids across a retort site, leaving a zone of unfragmented formation having a horizontal free face adjacent such a horizontal void. In one embodiment, such a horizontal void is excavated across less than the entire width of the retort site, leaving "side pillars" of unfragmented formation spaced inwardly from adjacent side boundaries of the retort site at opposite sides of such a horizontal void. This reduces the maximum span of the horizontal void, when compared with supporting overburden above the void with one or more interior isolated pillars spaced inwardly from the side boundaries of the retort. The side pillars are explosively expanded. Then such a zone of unfragmented formation is explosively expanded toward such a horizontal void for forming a fragmented permeable mass of formation particles containing oil shale in the retort.

Abstract: A process for gaining access to the coal of very deep seams, and for extracting this coal with the aid of a conveying liquid, which is fed to the seams via boreholes and is thence brought back again to the surface with coal which has been detached, wherein agents for detaching and breaking up the coal are admixed to the liquid.

Abstract: A device for breaking monolithic structures or pulsating by inducing pressure in a liquid filling a pre-drilled hole in the monolithic structure to be shattered comprises a tubular housing having a cavity for accommodating an explosive charge. Provided in the lower portion of the housing is a partition of an elastomeric material and a pipe serving to locate the device in a mouth of the hole and be filled with the liquid so as to form an air gap between the partition and the surface of the liquid. In order to retain the device inside the hole a means is provided connected to the housing and fashioned as an inertia element disposed outside the hole.

Abstract: A method for forming an in situ oil shale retort in a subterranean formation containing oil shale is provided. The in situ oil shale retort has top, bottom, and generally vertically extending side boundaries of unfragmented formation and contains a body of expanded oil shale formation that completely fills the retort to its top boundary. The retort is bulked full by explosively expanding a layer above a fragmented permeable mass of formation particles forming part of the body of expanded formation in the retort. The layer is expanded with an available void fraction of no more than about ten percent.

Abstract: An in situ oil shale retort is formed in a subterranean formation containing oil shale. The formation comprises at least one region of relatively richer oil shale and another region of relatively leaner oil shale. According to one embodiment, formation is excavated from within a retort site for forming at least one void extending horizontally across the retort site, leaving a portion of unfragmented formation including the regions of richer and leaner oil shale adjacent such a void space. A first array of vertical blast holes are drilled in the regions of richer and leaner oil shale, and a second array of blast holes are drilled at least in the region of richer oil shale. Explosive charges are placed in portions of the blast holes in the first and second arrays which extend into the richer oil shale, and separate explosive charges are placed in portions of the blast holes in the first array which extend into the leaner oil shale.

Abstract: Subterranean mineral deposits, such as oil shale or the like, are prepared for in situ retorting by selectively mining out an area at the base of the deposit leaving an overlying deposit supported in a suitable manner such as by a plurality of pillars. The overlying deposit is expanded in any suitable manner into the underlying area in a fashion to create a predetermined distribution of permeability from an area of low permeability to an area of high permeability. An inlet is provided at the low permeability area and an outlet at the high permeability area. A suitable medium is introduced into the deposit at the low permeability end for extracting and forcing mineral values from the deposit toward the outlet end for recovery. .Iadd.