Abstract: A device is provided for producing an acoustic signal in a liquid medium. The device includes a pneumatic chamber to contain a compressed gas volume, at least one pneumatic exhaust port allowing the compressed gas volume to be released out of the pneumatic chamber, and a shuttle movable along a translational axis during an opening phase, between two positions: a closed position in which the compressed gas volume is enclosed within the pneumatic chamber, and an open position in which the compressed gas volume is released out of the pneumatic chamber through the pneumatic exhaust port, to produce the acoustic signal in the liquid medium. A hydraulic brake is used to brake the shuttle during the opening phase. The hydraulic brake includes a hydraulic chamber and having a hydraulic exhaust area of a hydraulic volume out of the hydraulic chamber, and includes a control for controlling the acoustic signal.

Abstract: An improved seismic exploration system and method involves an overpressure wave generator for generating an overpressure wave and a coupling component for converting a pressure of said generated overpressure wave into a force that produces a conducted acoustic wave in a target media. The coupling component includes a coupling chamber, a push plate assembly including a top plate, piston rod, and an earth plate, a movement constraining vessel including a stabilizing component for constraining movement of the push plate assembly and a sealing component for substantially sealing the coupling component, and a stop component for preventing the movement constraining vessel from striking the earth plate.

Abstract: An air, fuel, and water mixture is injected into a resonance chamber forming micro-packets. The micro-packets are ignited forming micro-explosions in a combustion chamber containing a central resonance chamber creating a standing wave interfering with a standing wave in the resonance chamber generating the micro-packets. The interfering waves are in phase aiding in the disassociation of molecules, including hydrogen and oxygen, in the air, fuel and water mixture. Efficient combustion is achieved with a nearly zero carbon emissions. The heat generated from the combustion may be used to produce work by any conventional device, such as a steam engine or turbine or generate heat for a building.

Abstract: A seismic gun system for surveying underground geological topology, the seismic gun system comprising a projectile, a seismic gun body, a barrel, and a guide tube. The projectile includes an outer tubular jacket and a frangible material in its interior. A exterior surface of the tubular jacket is textured to regulate tubular jacket disruption. The barrel includes a breach end and a muzzle end. The breach end is connectable to the seismic gun body for receiving the projectile into said barrel and said muzzle end directing the projectile towards the bottom of a bore hole. The guide tube has an upper end and a terminal end. The upper end of the guide tube is connectable to the muzzle end of the barrel. The guide tube has walls to direct the projectile towards the bottom of the bore hole when aimed therein.

Abstract: An improved system and method for generating and controlling conducted acoustic waves for geophysical exploration are provided. A plurality of overpressure waves are generated by at least one overpressure wave generator comprising at least one detonation tube having an open end that may be directed away from, parallel to, or towards a target media. Recoil forces of the at least one overpressure wave generator, produced shear forces, or the forces of the plurality of overpressure waves are coupled to the target media to generate conducted acoustic waves. The timing of the generation of the plurality of overpressure waves can be in accordance with a timing code and can be used to steer the conducted acoustic waves to a location of interest in the target media.

Abstract: An improved system and method for generating and controlling conducted acoustic waves for geophysical exploration are provided. A plurality of overpressure waves are generated by at least one overpressure wave generator comprising at least one detonation tube having an open end. The at least one overpressure wave generator is oriented so the plurality of overpressure waves are not directed directly towards a target media. The recoil force of the at least one overpressure wave generator occurring during generation of the plurality of overpressure waves is coupled to the target media to generate conducted acoustic waves. The timing of the generation of the plurality of overpressure waves can be in accordance with a timing code and can be used to steer the conducted acoustic waves to a location of interest in the target media.

Abstract: An improved system and method for generating and controlling conducted acoustic waves for geophysical exploration are provided. A plurality of overpressure waves are generated by at least one overpressure wave generator comprising at least one detonation tube having an open end that may be directed away from, parallel to, or towards a target media. Recoil forces of the at least one overpressure wave generator, produced shear forces, or the forces of the plurality of overpressure waves are coupled to the target media to generate conducted acoustic waves. The timing of the generation of the plurality of overpressure waves can be in accordance with a timing code and can be used to steer the conducted acoustic waves to a location of interest in the target media.

Abstract: An improved system and method for generating and controlling conducted acoustic waves for geophysical exploration are provided. A plurality of overpressure waves are generated by at least one overpressure wave generator comprising at least one detonation tube having an open end. The at least one overpressure wave generator is oriented so the plurality of overpressure waves are not directed directly towards a target media. The recoil force of the at least one overpressure wave generator occurring during generation of the plurality of overpressure waves is coupled to the target media to generate conducted acoustic waves. The timing of the generation of the plurality of overpressure waves can be in accordance with a timing code and can be used to steer the conducted acoustic waves to a location of interest in the target media.

Abstract: An improved system and method for controlling and directing sound waves is provided. A fuel-oxidant mixture is supplied to at least one detonator having at least one spark initiator. The fuel-oxidant mixture flows through the at least one detonator and into the closed end of at least one detonation tube also having an open end. The timing at least one spark initiator is controlled to initiate at least one spark within the at least one detonator while the fuel-oxidant mixture is flowing through the at least one detonator thereby initiating a detonation wave at the closed end of the at least one detonation tube. The detonation wave propagates the length of the at least one detonation tube and exits the open end of the at least one detonation tube as a sound wave. When multiple detonation tubes are detonated with controlled timing, the resulting sound waves are directed to a desired location. Sound waves can be directed from groups of detonation tubes and from a sparse array of detonation tubes.

Abstract: An improved system and method for ignition of a gaseous or dispersive fuel-oxidant mixture is provided where a gaseous or dispersive fuel-oxidant mixture is supplied to a detonator tube having a fill point and an open end and an igniter placed at an ignition point within the detonator tube is ignited while the gaseous or dispersive fuel-oxidant mixture is flowing through the detonator tube. A detonation impulse is produced at the ignition point that propagates to the open end of said detonator tube where it can be supplied to a detonation tube having an open end, to an internal combustion engine, a combustion chamber, and to a pulse detonation engine.

Abstract: A seismic gun assembly comprising a barrel and guide tube assembly for delivering a projectile to the bottom of a bore hole with a non-line-of-sight section. The guide tube being either a large diameter guide tube or a tight fitted guide tube. The large diameter guide tube allowing the projectile to perform shallow angle bounces to reach the bottom of a non-line-of-sight bore hole. The tight fitted guide tube allows the projectile to ride the inner wall of the guide tube to reach the bottom of a non-line-of-sight bore hole. The projectile comprises an outer jacket and a frangible core. The seismic gun barrel assembly additionally comprises a fluid exclusion puck for preventing fluids from entering the guide tube, a suppressing collar for suppressing seismic noise, and a method for modulating recoil.

Abstract: An improved system and method for ignition of a gaseous or dispersive fuel-oxidant mixture is provided where a gaseous or dispersive fuel-oxidant mixture is supplied to a detonator tube having a fill point and an open end and an igniter placed at an ignition point within the detonator tube is ignited while the gaseous or dispersive fuel-oxidant mixture is flowing through the detonator tube. A detonation impulse is produced at the ignition point that propagates to the open end of said detonator tube where it can be supplied to a detonation tube having an open end, to an internal combustion engine, a combustion chamber, and to a pulse detonation engine.

Abstract: An improved system and method for controlling and directing sound waves is provided. A fuel-oxidant mixture is supplied to at least one detonator having at least one spark initiator. The fuel-oxidant mixture flows through the at least one detonator and into the closed end of at least one detonation tube also having an open end. The timing at least one spark initiator is controlled to initiate at least one spark within the at least one detonator while the fuel-oxidant mixture is flowing through the at least one detonator thereby initiating a detonation wave at the closed end of the at least one detonation tube. The detonation wave propagates the length of the at least one detonation tube and exits the open end of the at least one detonation tube as a sound wave. When multiple detonation tubes are detonated with controlled timing, the resulting sound waves are directed to a desired location. Sound waves can be directed from groups of detonation tubes and from a sparse array of detonation tubes.

Abstract: A method of generating seismic waves in a rock mass surrounding a well comprises the steps of: (a) providing a packer and a fluid withdrawal line within the well, wherein the packer is located below the weathering zone and defines the upper limit of a working volume within the well, and the fluid withdrawal line is adapted to withdraw fluid from the working volume; and (b) providing and detonating an air-fuel mixture in the working volume to generate seismic waves, combustion products of the detonation being withdrawn from the working volume via the fluid withdrawal line.

Abstract: A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

Abstract: A sound mitigation system and method reduce the transmission of acoustic output from explosions underwater. The system is submerged to bottom terrain of a body of water and has at a series of gas-generating devices providing volumes of gas that are fed to refractory heat resistant tubing assemblies and flexible general tubing assemblies. The heat resistant and general tubing assemblies extend between adjacent gas generating devices and are provided with at least one row of holes to vent bubbles of gas and form a virtually continuous curtain of bubbles rising to the surface of the water between detonating explosives and areas of interest. The curtain of bubbles mitigates the effects of the explosions on marine mammals and endangered, threatened, or protected species within an area adjacent to the explosions.

Abstract: A sound mitigation system and method reduce the transmission of acoustic output from explosions underwater. The system is submerged to bottom terrain of a body of water and has at a series of gas-generating devices providing volumes of gas that are fed to refractory heat resistant tubing assemblies and flexible general tubing assemblies. The heat resistant and general tubing assemblies extend between adjacent gas generating devices and are provided with at least one row of holes to vent bubbles of gas and form a virtually continuous curtain of bubbles rising to the surface of the water between detonating explosives and areas of interest. The curtain of bubbles mitigates the effects of the explosions on marine mammals and endangered, threatened, or protected species within an area adjacent to the explosions.

Abstract: A method of generating seismic waves in a rock mass surrounding a well comprises the steps of:

Abstract: Disclosed are new apparatus and methods for transmitting and enhancing the propagation of acoustic signals through a well tubing while providing a vent port. The apparatus and methods can be used to control subsurface well tools without wire or line connections to the surface.

Abstract: A seismic pulse generator (1) has a chamber (4) pressurised with gas. The generator includes a solenoid valve (60) which can be actuated to cause the release to atmosphere of only a small amount of pressurised gas from a small control chamber (34) behind a main piston (30) to enable the piston to move away from a valve seat (32) around an outlet (26). This permits the abrupt release of the pressurised gas in the chamber (4) through the outlet and the “firing” of the generator. The arrangement maximises the use of the main pressurised gas for actual “firing” of the generator.

Abstract: A self-firing and self-propelling gas impulse device which includes a housing having a longitudinal axis, a gas inlet port, and one or more gas discharge ports; an inlet chamber, arranged for gas communication with a source of compressed gas via the inlet port and operative to receive compressed gas therefrom; a pressurization chamber arranged for gas communication with the inlet chamber thereby to facilitate a build-up of pressurized gas therein, and arranged for selectable gas communication with the one or more discharge ports; and a piston unit arranged along the longitudinal axis of the housing between the inlet chamber and the pressurization chamber.

Abstract: A well tool in accordance with the invention comprises an attenuation device which attenuates tube waves associated with an elastic wave emission and/or reception set (1, 12). The attenuation device comprises a bubble generator (2) which releases into the well a gas not readily soluble in the well fluid, slightly overpressured in relation to the hydrostatic pressure, in the form of calibrated bubbles which greatly attenuate the parasitic tube waves. The attenuation device is placed above or below the elastic wave emission and/or reception set having a plurality of pickups whose signals are acquired by a local electronic module (14) and/or a source of elastic waves such as a vibrator. A bubble trap (17) is preferably associated with the bubble generator (2) in order to limit the volume of gas to be generated in situ. The invention is applicable to VSP type seismic prospecting and acoustic logging.

Abstract: There is provided an acoustic source especially for use in seismic studies at sea. The acoustic source has a longitudinal axis and sound emitting surfaces adapted to be put into sound emitting movements towards and away from each other by use of a drive unit. The sound emitting surfaces comprise two curved plate members having upper and lower ends essentially symmetrically positioned in relation to the longitudinal axis of the acoustic source, and forming a convex cross section with their respective upper and lower edges converging towards each other. The upper and lower edges of the sound emitting surfaces, respectively, are connected to each other with two corresponding side elements, the side elements each being connected to at least one hinge stretching along at least a part of the length of the source.

Abstract: Acoustic source, especially for use in seismic studies at sea, with sound emitting surfaces adapted to be put into sound emitting movements toward and away from each other by use of a drive unit in a known manner, in which the sound emitting surfaces comprise two curved plate members essentially symmetrically positioned in relation to the longitudinal axis of the source, forming a convex cross section with their respective upper and lower edges converging towards each other, and the respective upper and lower edges of the sound emitting surfaces are flexibly connected to two corresponding side elements positioned between them, and that the source comprises a rigid frame for supporting the drive unit, comprising at least two rigid slide rods stretching through the side elements, and that rigid covers are mounted on the slide rods, covering at least the whole side elements, thus forming rigid, covering surfaces with a constant distance between the covers.

Abstract: A pulsed combustion acoustic wave generator includes a tubular barrel having an inlet end and an open outlet end, a fuel controller for metering a controlled quantity of fuel into the inlet end of the barrel, an oxidant controller for metering a controlled quantity of oxidant into the inlet end of the barrel and an igniter extending into the inlet end of the barrel that is controllable by an operator to ignite a mixture of fuel and oxidant in the inlet end.

Abstract: A two-phase shock wave generator including a combustion chamber including a first, combustion, portion having an input port and a second, detonation, portion downstream of the first portion and having an output aperture; an air-fuel supply line, operative to feed the input port with an air-fuel mixture, an igniter, associated with the air-fuel supply line, which ignites the air-fuel mixture in the supply line and initiates a burning front which propagates towards the input port and a turbulence stimulator, fixedly mounted in the combustion chamber, which enhances and controls burning of the air-fuel mixture and includes a first section, situated within the combustion portion of the combustion chamber and having a preselected first gas dynamic resistance and a second section, situated within the detonation portion of the combustion chamber and having a preselected second gas dynamic resistance, lower than the first resistance, wherein the first resistance is such that burning of the air-fuel mixture in the com

Abstract: A closed-cycle combustion low-frequency acoustic pulse source for use underwater. An elongated combustion chamber, having a first end and a second end and an elongated elastic sleeve, is filled with a stoichiometric mixture of oxygen and hydrogen from an electrolyzer. When the mixture is ignited at the first end of the chamber, a longitudinally traveling flame front is initiated at the first end of the chamber. The moving front results in a traveling thermal pressure pulse. The pressure pulse is communicated to the surrounding underwater medium producing a generally uni-directional acoustic pressure pulse along the longitudinal axis of the elongated chamber. An alternative embodiment utilizes an array of sources disposed along the generally horizontal longitudinal axis of the array.

Abstract: An impact-type surface seismic source utilizing a closed air system includes a heavy pistons supported above an earth contacting base plate partially within a hollow upstanding cylindrical housing, having a closed top and an open bottom. The housing side walls are provided with ports which communicate with a source of high pressure air. Preparatory to a firing operation, the piston blocks these ports, but upon a firing signal the piston is released and falls under gravity permitting high pressure air to enter the bore of the housing through the ports, thus driving the piston downwardly to strike the base plate. As the piston is retrieved and nears its original position, blocking the side ports, it mechanically actuates a valve so as to vent any air trapped above the piston within the housing bore. The vent remains open until the piston again falls.

Abstract: In the art of acoustic well sounding a gas-gun for the sudden discharge of a measured quantity of compressed gas, comprised of two chambers, viz. a discharge chamber closed at one end by a poppet, and on the opposite end by a power-head, the latter a cylinder including a sealed piston, with the poppet connected by sealed piston rod penetrating the cylinder head, and terminated at the piston. The entire assembly to be so proportioned that regardless of the position of the piston a gap remains between the piston and the cylinder-head penetrated by the piston rod. Means for connecting this gap to the inside of the discharge chamber through a check valve permits gas flow from the discharge chamber to the gap, but not in the reverse direction, and means for venting the gap to the atmosphere. A passage from the opposite side of the piston to the axial outlet of the discharge chamber, a spring or a positive locking device for pressing the poppet against the valve seat.

Abstract: An air gun is mounted in a reaction mass having an impulse-transmitting ground-contact plate movably mounted below the mass. This mass is in face-to-face contact with the plate over the major portion of the entire upper surface of the contact plate. Confined liquid is not employed. The air gun is charged with pressurized gas and fired, discharging the pressurized gas into the narrow horizontal interface region between reaction mass and plate. Rapid expansion of the discharged gas between mass and plate causes an intensely powerful seismic impulse to be transmitted into the earth. The air gun has a firing chamber for holding a charge of pressurized gas, a movable shuttle for suddenly discharging the pressurized gas, including upper and lower pistons with a hollow member connecting these pistons. A pedestal assembly carrying said shuttle is mounted from above to the reaction mass and extends down into the hollow shuttle member.

Abstract: A movable inner cylindrical valve member is rigidly attached to the upper end of an air powered impact projectile designed for striking a target to produce an acoustic pulse. By seating upwardly within the bore of a fixed outer valve member against spaced apart tapered valve faces, the cylindrical wall of the inner valve member covers intermediate air pressure ports in the bore wall. In operation, the axial separating movement between the inner and outer valve members will instantly admit air pressure adjacent the closed end of the bore of the outer valve member in order to exert an accelerating force to drive the projectile. At the same time, the operation of this valve can be made essentially pressure independent by proper selection and placement of the annular seals which contact the valve faces.

Abstract: Apparatus for generating an acoustic pulse in a medium wherein an impact piston is driven downwardly along a cylindrical housing by compressed gas to strike a rigid target positioned in contact with the earth. In its firing position, the tapered upper portion of the piston extends above the top of the housing within a container occupied by the compressed gas, the top of the piston being at the same time recessed within a gastight mating enclosure at the top of the container. In this position, the tapered piston surface is constantly exposed to circumferential gas pressure so as to provide a positive breakaway force. Upon release of suitable piston latch means, the piston is first urged downwardly by this breakaway force and thereafter accelerated more powerfully when the top of the piston separates from the enclosure and becomes exposed to gas flow uniformly from all directions.

Abstract: The shear wave source of this invention includes a housing and means for applying forces to the shot hole wall. The force applying means applies a number of forces to the shot hole wall along lines normal to a plane close to the shot hole. No pressure waves, but only shear waves are generated at distant points on the plane. At least one of the forces is applied in opposite direction to the other forces to reduce the net recoil of the housing.A first, second and third force are applied at three source points in the observation plane along three lines normal to the plane to generate respectively a first, second and third shear wave in the plane. The first and third forces are equal in magnitude and the second force has twice the magnitude of the first force. The first and third forces are applied along lines in the same direction, but the second force is applied along a line opposite in direction to the lines of the first and third forces.

Abstract: A gas gun assembly for measuring depths of reflectors in a well bore includes a housing having a central chamber and bottom bulkhead through which a first valve bore extends. Coupling structure is provided to connect the housing to the well. A cap closure for the chamber has a second valve bore therethrough of diameter larger than the diameter of the first valve bore and is located in axial alignment with the first valve bore. A valve stem has one end axially movable within the second valve bore while closing the same and the other end movable into and out of the first valve bore. A predetermined pressure condition is established across the bulkhead. The valve stem is then released for rapid equalization of pressure across the bulkhead to produce an acoustic pulse in the well bore.

Abstract: A transportable, acoustic pulse generator is described employing an impact mass suspended above a freely movable target plate positionable on the ground, the impact mass being forceably propelled downwardly to strike the target plate to generate an acoustic pulse adapted for seismic purposes. The generator housing is adapted to be mounted on the rearwardly extending rails of a conventional transport truck. In order to eliminate bouncing of the truck due to generator housing recoil on firing, the housing itself is jacked up by lift cylinders extending upward from the target plate so as to minimize or eliminate the spring suspension of the truck. Upstanding sleeve guides carried on the generator housing cooperate with the lift means to provide lateral stability and to establish a precise vertical separation between the impact mass and the target plate, thus insuring repeatable signal energy content and timing.

Abstract: Apparatus for generating an acoustic pulse in a medium including an upstanding cylindrical housing within which an impact piston supported by retainer springs is adapted to be propelled downwardly by high pressure expanding gas supplied from external high volume accumulators so as to a strike target plate resting on the ground adjacent the lower end of the housing. A small valve in the top of the cylinder is opened to supply sufficient gas pressure to overcome the spring bias and initiate piston motion. When the piston moves downward far enough to expose multiple large area ports in the housing side wall interconnected with the accumulators, the sudden inflow of gas pressure produces rapid piston acceleration and high energy impact with the target.

Abstract: Apparatus for generating an acoustic pulse in a medium including an upstanding cylindrical housing within which an impact piston retained in the upper end of housing by an electrically controlled latch is driven downwardly by compressed gas to strike a target plate positioned adjacent the bottom of the housing. The compressed gas is provided by high volume accumulators interconnected with large area ports penetrating the sidewall of the housing near its top. The tapered upper portion of the piston presses against static seals mounted on the correspondingly tapered housing bore above and below these ports. This taper enables the compressed air to exert a positive break away force on the piston. Quick release of the latch triggers the downward thrust of the piston to deliver a blow against the target plate.

Abstract: Apparatus for generating combined compressional and shear wave signals in the earth which employs a seismic source, such as a cylindrical gas exploder, having a free-moving wedge shaped base which tapers symmetrically downwardly to a thin blade. When the exploder is fired at an angle inclined to the vertical, a force is generated along its longitudinal axis which drives the base downwardly in the same direction so as to propagate seismic signals having a compressional component and a shear component. The blade is disposed transversely to the direction of the horizontal component of this applied force. The penetration achieved by the thin blade portion of the base insures sufficient earth coupling to generate high energy shear seismic signals and minimizes horizontal translation of the exploder under a wide range of soil conditions.

Abstract: A system for vibrating the earth in a location where seismic mapping is to take place, including forming a relatively shallow hole in the earth such as a hole 10 feet deep, placing a solid propellant in the hole, sealing a portion of the hole above the solid propellant with a device that can rapidly open and close to allow a repeatedly interrupted escape of gas, and igniting the propellant so that high pressure gas is created which escapes in pulses to vibrate the earth.

Abstract: A seismic land source for transmitting powerful seismic energy impulses into the earth comprising a dome-shaped bell within which is contained a substantially incompressible liquid and an air gun which can be fired for abruptly releasing pressurized gas into the liquid in the bell. A metal pan is positioned below the rim of the bell for engaging the surface of the earth below the bell and is mounted for downward movement with respect to the bell. A flexible elastomeric diaphragm extends across the bottom of the bell above the metal pan and extends upwardly beyond the bell rim between the rim and the pan. The diaphragm has a rounded shoulder portion with an upturned peripheral side wall portion extending upwardly around the exterior of the bell to an elevated level substantially above the bell rim, and the upper edge of the peripheral side wall of the diaphragm is clamped at said elevated level to a flange fixed to the outer surface of the bell.

Abstract: A seismic wave generator assembly with self-contained guidance and shock-absorbing means is confined within an elongated, upstanding cylindrical housing which may be lowered into position at the end of a lateral arm or a cable supported from a transport vehicle.

Abstract: Within a stationary upstanding cylindrical housing, a piston and a base member resting on the ground are separated by an expansible detonation chamber. Means are provided for feeding successive charges of a combustible gas mixture into the chamber at a rapid rate and initiating a corresponding series of gas explosions therein. Recoil of the piston following each explosion compresses a first air spring which then forcibly thrusts the piston downwardly. Piston recovery for the next cyclic operation is thereafter slowed by means of a second air spring-dashpot combination.

Abstract: The gas detonator is especially adapted for shallow, seismographic, land prospecting. It comprises a circular bottom plate having an inwardly-directed sloping side wall. An annular top plate is mounted over the bottom plate. Means, including a plurality of springs, interconnect and resiliently maintain the plates in touching relation with each other. A housing is mounted over the top plate and forms therewith a detonation chamber. The bore of the top plate serves as the vent port for the detonation chamber. The vent port is normally closed by the bottom plate. Following the detonation of a combustible gas mixture in the chamber, the plates momentarily separate and form therebetween a cylindrical cavity which opens the vent port. A container upwardly extends from and forms with the bottom plate a reservoir which, in use, is filled with water. The spent gases of combustion escape into this water, thereby muffling the sound of the detonator.

Abstract: Within a stationary, upstanding cylindrical housing, a piston and a base member resting on the ground are separated by an expansible detonation chamber. One or more gas inlets communicate with the chamber through which successive charges of a combustible gas mixture may be fed into the chamber at a rapid rate and thereafter ignited to initiate a corresponding series of gas explosions. Each gas inlet is connected to a main gas flow conduit which is supplied from at least two independent mixers through separate branching conduits. The mixers are supplied in rotation from sources of fuel gas and oxidizing gas so that only one branch conduit is in use at a time. Spark ignition occurs at each mixer in the same rotation. The branch conduits are connected to the main gas flow conduits in geometrical arrangements which prevent preignition even in long rapid fire shot sequences.

Abstract: Within the stationary, upstanding cylindrical housing of a rapid fire seismic gas exploder an expansible detonation chamber is formed between a base resting on the earth and a piston adapted to move reciprocally. A plurality of separate external gas entry conduits communicate with the detonation chamber at spaced apart inlets in the wall of the housing. Each conduit is supplied from its own separate gas mixer which in turn is interconnected with sources of fuel gas and oxidizing gas through a pair of remotely operable flow control valves. As the pairs of control valves are actuated in timed sequence at a desired rate of fire, successive charges of combustible gas mixture are injected into the detonation chamber, utilizing one mixer and its associated gas entry conduit at a time. Correspondingly timed spark ignition is provided in or adjacent each mixer, resulting in a series of gas explosions in the chamber which coordinates with the reciprocal movement of the piston.

Abstract: This invention concerns a device for emitting shock-waves, with adjustable capacity.Such a device comprises a valve, a barrel with a seat for this valve, barrel and valve being on the same axis, and forming between them an annular combustion chamber, which can be placed in communication with the outside atmosphere by axial movement of the valve, and which comprises means of admitting the oxidant-fuel mixture, the said valve forming a differential piston, one side of which forms a mobile wall of a pressurized fluid chamber, and part of the other side of which forms a mobile wall of the combustion chamber. In this device a fixed wall of the combustion chamber contains at least two regularly spaced apertures at its perimeter, into which fit removable plugs, each of which comprises a cavity opening into the combustion chamber, and which comprise means of admitting fuel and oxidant, and ignition means. The device generates compression waves for seismic exploration.

Abstract: A high-frequency, high-repetition gas detonator is provided which is adapted for shallow seismographic work. The detonator comprises a detonation chamber, a rigid bottom plate adapted to be coupled to the earth, and a top plate positioned over the bottom plate. A plurality of springs resiliently hold the plates together whereby the bottom plate covers a bottom vent port in the chamber when the plates engage. The bottom plate opens the chamber to the surrounding medium when the plates disengage. Fluid conduit means communicate with the interior of the chamber for supplying thereto a pressurized detonating fluid. Means are provided for detonating the fluid thereby causing the bottom plate to move downward and separate from the top plate. The compressive force of the bottom plate sends a downward seismic pulse into the underlying layers of the earth. The products of detonation from the detonation chamber are vented outside through the cavity formed between the top and bottom plates when the plates are separted.

Abstract: This invention describes an apparatus and method for generating seismic waves in the earth for seismic geophysical prospecting. It involves a slender pipe open at the lower end, which can be driven into the earth to a shallow depth. The upper end is closed. Means are provided for introducing oxygen and acetylene through a pair of control valves and check valves, for a selected period of time. The oxygen and acetylene are mixed in the pipe and flow downward through the pipe and through the perforations into the earth, and fill the voids and fissures in the shallow sediments. Means are provided in the top end of the pipe to detonate the gas mixture. The detonation wave travels down the pipe and eventually reaches the openings at the lower end, and detonates the gas in the pores and fissures of the earth. The resulting explosion opens up the fissures and provides a larger void space than was there before.

Abstract: An expandable ignition chamber within an upstanding cylinder is formed between its base and a massive free piston. Initial detonation of a combustible gas mixture within the chamber drives the piston upwardly to expose in sequence a series of vertically spaced gas inlets in the cylinder wall, through which the supply of gas is replenished to support a corresponding sequence of additional rapidly timed detonations. Repetitive seismic pulses are thereby supplied by the downward thrust of the base which is itself slidable with respect to the cylinder walls.

Abstract: Arms extending laterally from an upwardly moving weight, such as a rebounding seismic gas exploder, terminate in guide assemblies adapted to engage a plurality of parallel semi-rigid, resilient ropes connected between the top and the bottom of a supporting frame so that the weight must follow their path. Each guide assembly contacts its respective rope at several vertically spaced positions so as to distribute side loads along the rope resulting from eccentric exploder movement. The construction prevents the exploder from tilting sufficiently to catch or lock on the one or more ropes, thus avoiding pendulum movement of the exploder and abrasion of the ropes.