Abstract: Subterranean oil and gas producing formations are fractured by providing one or more combustion gas generating units using rocket fuel type propellants disposed in a well casing at preselected depths. The well casing is filled with a compressible hydraulic fracturing fluid comprising a mixture of liquid, compressed gas, and propant material and precompressed to a pressure of about 1,000 psi or more greater than the fracture extension pressure at the depth of the zone to be fractured. At least one of the gas generating units is equipped with perforating shaped charges to form fluid exit perforations at the selected depth of the fracture zone. The gas generating units are simultaneously ignited to generate combustion gasses and perforate the well casing. The perforated zone is fractured by the rapid outflow of an initial charge of sand free combustion gas at the compression pressure followed by a charge of fracturing fluid laden with propant material and then a second charge of combustion gas.

Abstract: An oil or gas well is completed by cementing a casing string in a well having a special joint providing incipient perforations therein. The incipient perforations are closed during the cementing of the casing string in the well bore and are opened after the cement sets up. Preferably, the incipient perforations are opened concurrently with the fracturing of the cement sheath and the formation from which production is desired. The perforations of this invention are quite large and bear a ratio with the quantity of propellant in which there is at least 14 square inches of casing openings per cubic foot of propellant.

Abstract: The fixation of a packer or other borehole device is provided by explosively bonding the device to the borehole casing in the desired location. The explosively set packer is oriented in the borehole casing on a setting tool which preferably includes a casing scraper to clean the interior surface of the borehole casing, a removable packer to trap a gas pocket in the area where the explosive bonding is to occur and a gas transfer apparatus to form a gas pocket below the removable packer after the removable packer has been set.

Abstract: A method of fracturing subsurface formations is provided which utilizes a mixture of a propellant and a propping agent. According to another aspect a mixture of a combustible material such as a propellant and a propping agent along with another composition which includes a combustible material are deposited in a borehole from a conduit system which is raised continuously through the borehole. After such deposition, the deposited compositions are ignited so as to cause fracturing of the formation around the borehole.

Abstract: A system for perforating a well with an annulus pressure firer is provided by the present invention. A pressure responsive means is positioned in a tubing string uphole a packer and includes a piston movable in response to a pressure differential between the upper annulus pressure and the pressure inside the tubing string. The movement of the piston is transferred through a second, concentric tubing string to a firing head on a perforating gun below the packer. The system includes a means for simultaneously decoupling the concentric tubing strings below the packer to drop the perforating gun to the bottom of the well.

Abstract: Subterranean oil and gas producing formations are fractured by providing one or more combustion gas generating units using rocket fuel type propellants disposed in a well casing at preselected depths. The well casing is filled with a compressible hydraulic fracturing fluid comprising a mixture of liquid, compressed gas, and propant material and precompressed to a pressure of about 1,000 psi or more greater than the fracture extension pressure at the depth of the zone to be fractured. At least one of the gas generating units is equipped with perforating shaped charges to form fluid exit perforations at the selected depth of the fracture zone. The gas generating units are simultaneously ignited to generate combustion gasses and perforate the well casing. The perforated zone is fractured by the rapid outflow of an initial charge of sand free combustion gas at the compression pressure followed by a charge of fracturing fluid laden with propant material and then a second charge of combustion gas.

Abstract: Methods and apparatus are provided for detonating high explosive devices downhole in a well. A high explosive device includes a detonating cord having a first end and a second end. A first device is provided for initiating a detonation of a detonating cord at its first end and a second device is provided for initiating a detonation of the detonating cord at its second end.

Abstract: An apparatus which comprises an upper sub for connectable engagement with the wire line, a microprocessor component for directing the various functions of the overall apparatus down hole; a motor section having a plurality of thrust directional motors and ball screw assembly for movement of steering gates; a motor driven impeller means for providing thrust and flow through a portion of the apparatus and in combination with the flow gates providing steering in a certain direction; an electrical transducer portion for providing ultrasonic vibrations around the circumference of the apparatus in discongealing molecular substrate adjacent the apparatus; a mechanical vibration coil assembly means on the lower end of the apparatus for discongealing larger areas of congealing in a substrate around the apparatus, and a lower sub for connectably engaging the electrical logging unit to be steered down hole.

Abstract: An explosive perforating tool has an elongated barrel having a piston disposed substantially within. A radial passage extends from the outer surface of the barrel into the longitudinal cavity, thereby allowing the piston to be explosively driven from the tool through the radial passage. The piston has a longitudinal opening therethrough. When an explosive charge is set off increasing the pressure of a lubricating fluid within the longitudinal cavity, pressure is uniformly built up all around the piston and is the primary mode of force propelling the piston against the tubing. Vent openings are provided in the elongated chamber to allow the lubricating fluid to escape, thereby regulating the rate of pressure dissipation within the cavity to control the force with which the piston is propelled against the tubing. Spacers of varying size can be attached to the barrel to allow the tool to be used in different sizes of tubing.

Abstract: A chemical cutting apparatus for use within a well bore is disclosed. The apparatus of the present invention includes a tubular casing adapted to be lowered into a well bore. The tubular casing contains an internal chamber containing a chemical cutting fluid. A remotely operated explosive charge pressurizes the chamber of chemical cutting fluid and simultaneously forces chemical cutting fluid out through a discharge passage and erects a plurality of slips which anchor the tubular casing within the well bore. After a cutting operation has taken place, pressure buildup within the tubular casing which occurs as a result of a clogged discharge passage may be vented or bled off by the selective opening of a second discharge passage, thus preventing undesired engagement of the anchor slips during removal of the apparatus. In a preferred embodiment of the present invention, an interlock is provided which prevents the opening of the second discharge passage prior to ignition of the explosive charge.

Abstract: A device for actuating an explosive charge downhole in a wellbore. The device includes a combustive reaction initiator actuated in response to a first pressure condition in a portion of the wellbore and an explosive charge actuator. A time delay device is provided wherein a combustive reaction is initiated by the initiator and continues for a time delay period providing sufficient time for an operator to alter the first pressure condition to a second pressure condition desired at the time of explosive actuation. The delay device is operative at the end of the time delay period after initiation to actuate the explosive charge.

Abstract: Discloses an improved tool and method for cutting material by expelling a jet stream of liquid chemical reactant into forceful flowing connection and chemical reaction with a designated area of the material. Applies a force to at least one mass of reactant to move the mass through at least one jet orifice into flowing connection with material to be cut. Improvement is provision of a double rupture membrane adapted to confine the reactant mass until force is applied.

Abstract: Two or more spaced formations located downhole in a borehole are completed by employment of a string of perforating guns and by making a single trip to the wellbore. An upper and a lower gun device are tied together by a connecting tubing. The length of the tubing spaces the guns apart a selected amount. The gun string is run downhole and actuated, whereby the casing is perforated adjacent to the two spaced formations. Detonation of the upper gun forces an upper movable member associated with the connecting tubing to generate a pressure wave which is received by a lower movable member located at the upper end of the lower gun. The lower member is connected to cause detonation of the lower gun.

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 cord 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: An apparatus for plugging a wellbore with a solid gel plug stem in high impulse or high energy fracturing. This apparatus facilitates the removal of the propellant canister support means, the propellant ignition means, as well as any debris adhering thereto. By this apparatus, damage to the wellbore and formation is minimized.

Abstract: A time-delayed ignition system for a down-hole explosive tool such as a wireline cutter. The ignition system preferably includes: (a) a longitudinal housing; (b) means for supplying electrical current to the housing; (c) an electrical igniter located in the housing and operable to activate the down-hole tool by applying the electrical current to the igniter, and (d) means for delaying application of the current to the igniter until a predetermined period of time has elapsed. Preferably, the time-delay means are electronic and disposed within the housing.

Abstract: An apparatus is provided for use in detonating explosives positioned in a well. The apparatus includes a first coupling member and a second coupling member. The first coupling member is joined to a housing containing explosives. Both the first coupling member and the second coupling member have conductor wire joined thereto. The first coupling member is hollow and of a size to matingly receive the second coupling member therein. Each coupling member is separately located near a desired location in the well. Then the coupling members are matingly joined together and electrical energy is delivered to the conductor wire of the second coupling member. By means of inductive coupling, electrical energy is provided to the conductor wire of the first coupling member. The electrical energy is used to detonate the explosives to produce a hole in a well casing at the desired location.

Abstract: A sonic fracing process and means to enhance production of oil and gas wells, increasing formation permeability by creating sonic waves that cracks and loosens the formation interstices. The sonic waves are created by a series of directed detonations and harmonic pulsations. The explosive material is placed inside the well bore and detonated from the surface. Two methods commonly used to increase formation permeability are known as Acidizing and/or Hydraulic Fracturing. The Sonic Frac has been designed to complement these fracing processes.Three inherent benefits are derived by using the Sonic Frac Process. First, and most important, is that the fine formation fissures are cracked and "opened" to allow flow of oil or gas to migrate from pores that would otherwise not be affected by conventional fracing processes. Second the pressure pulsations, which are created by the expansion of the gas utilized in conjunction with the Sonic cause the fluid in the wall bore to oscillate through the perforated zones.

Abstract: A back-off tool comprising an explosive contained in a tubular housing which will disintegrate into fine particles upon detonation of the explosive. The explosive may be in the form of pellets so as to have the capability to vary the amount of explosive force by employing different diameter pellets and different numbers of pellets in the housing. A pressure compensation arrangement may be employed.

Abstract: A tool for actuating a subsurface well tool located within a well bore by metering the force applied by hydrostatic pressure within the well bore is disclosed. The tool is actuated in response to an external signal whereby hydrostatic pressure is applied to a hydraulic fluid contained within the tool. The hydraulic fluid is metered to apply a prescribed actuating force to a piston with a metering orifice determining the rate at which force is applied to the actuating piston and to the well tool.

Abstract: An apparatus for stimulating a subterranean formation uses a gas generating propellant placed in the well adjacent the formation to be stimulated. The propellant is ignited to generate gas at sufficient pressure and in sufficient volume to fracture the formation to thereby improve its permeability or productivity. The device is designed to generate an initial pressure pulse of substantial amplitude to initiate fractures in the formation. Shortly, the pressure generated by the device falls off to a lower value and is sustained at that value for a relatively substantial length of time.

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 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: An apparatus which comprises an upper sub for connectable engagement with the wire line, a microprocessor component for directing the various functions of the overall apparatus down hole; a motor section having a plurality of thrust directional motors and ball screw assembly for movement of steering gates; a motor driven impellar means for providing thrust and flow through a portion of the apparatus and in combination with the flow gates providing steering in a certain direction; an electric transducer portion for providing ultrasonic vibrations around the circumference of the apparatus in discongealing molecular substrate adjacent the apparatus; a mechanical vibration coil assembly means on the lower end of the apparatus for discongealing larger areas of congealing in a substrate around the apparatus, and a lower sub for connectably engaging the electrical logging unit to be steered down hole.

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 downhole chemical cutting tool having an improved cutting section. The tool comprises an elongated tool body adapted for insertion into a well bore and includes anchoring means actuatable between a deployed position in response to the application of fluid pressure and a retracted position in response to the release of such pressure. The tool further includes a chemical section and a cutting section located in front of the chemical section. The cutting section has a longitudinally extending bore which is in fluid communication with the chemical section at the rear of the cutting section and in fluid communication with the exterior of the tool body at the front of the cutting section. The cutting section is provided with one or more cutting ports through which the cutting fluid passes when the tool is fired. A piston is slidably disposed in the bore of the cutting section at a location between the ports and the chemical section.

Abstract: A safety joint for use in a pipe string, particularly one incorporating testing tools, comprising a substantially tubular outer housing with an automatic J-slot cut into the interior surface thereof. A mandrel having a spline radially protruding therefrom along its upper longitudinal extent and a J-slot lug also protruding therefrom below the spline and to a greater radial extent is slidably contained within the housing and is initially prevented from sliding within it by a tension sleeve which is designed to part in response to a predetermined tensile force. To operate the safety joint, the pipe string is set down and right-hand torque applied, after which tension is applied to the pipe string until the tension sleeve parts, whereupon the mandrel moves upwardly with respect to the housing, the J-slot lug being constrained to follow the path of the J-slot. The right-hand torque and upward pipe string movement causes a mandrel retaining nut at the top of the housing to back off therefrom.

Abstract: A self powered downhole tool anchor device (10) preattached to a downhole tool (T) and unitarily supported by a drill string (DS) for a single trip into a well bore, actuated by forceful engagement with the bottom or plug (P) in the well bore and attachment to a well bore casing (C). The anchor device comprises an inner mandrel (20) and lower cone (34) containing a piston (30) and fluid (F) for axially displacing an outer mandrel and piston (44) connected thereto by shear screws (46). An upper cone (20) on the outer mandrel is connected by shear pins to a slip housing (50) containing radially expandable slips (38) keyed to the lower cone (34).

Abstract: Discloses a method and apparatus to help provide fluid pressure in a well bore sufficient to overcome in situ earth formation pressures by perforating a circulation port through the sidewall of a drill collar above the drill bit to provide circulation of weighted drilling fluid down through the drill spring and back up the well annulus. Includes the lowering of a chemical reactant wireline perforating tool to a designated position within a drill collar, placing a single chemical flow jet into position addressing the sidewall of the drill collar, forcing the chemical reactant through the jet under high pressure and at high temperature to react with the drill collar metal and thereby remove a portion of the metal with the remaining metal defining a fluid circulation port through the drill collar wall, and pumping fluid through the port to establish circulation.

Abstract: Method and apparatus in which a hydrocarbon-bearing well formation penetrated by a borehole is fractured with apparatus located outside the well by injecting gases into the well to elevate the pressure and temperature within the well formation and to maintain the elevated pressure and temperature until the formation is fractured, the apparatus including a gas generator of the type in which a fuel, such as hydrogen peroxide, is decomposed by a catalyst to form high temperature decomposition gases, such as steam and oxygen, and an air compressor for injecting compressed air into the well to aid in raising the pressure within the well formation so as to pack the decomposition gases into the formation and to maintain the raised pressure until the formation is fractured.

Abstract: Downhole well tools and anchoring means therefore including a chemical cutting tool having improved slip actuating and slip array assemblies. The cutting tool includes a slip shaft provided with fluid passageway and having a slip array slidably disposed thereon. The tool further includes slip expansion means secured to the shaft adjacent to the slip array. A piston sleeve is slidably disposed on the shaft and connected to the slip array and defines a piston chamber in fluid communication with the shaft passageway such that the application of fluid pressure drives the piston sleeve and slip array to a deployed position in which the slip array is expanded. Biasing means located externally of the piston sleeve function to bias the piston sleeve to a retracted position upon release of fluid pressure. The slip array is comprised of spaced slip segments which are biased inwardly by means of cantilever springs secured to a structural member of the logging tool.

Abstract: An improved downhole steam injector has an angled water orifice to swirl the water through the device for improved heat transfer before it is converted to steam. The injector also has a sloped diameter reduction in the steam chamber to throw water that collects along the side of the chamber during slant drilling into the flame for conversion to steam. In addition, the output of the flame chamber is beveled to reduce hot spots and increase efficiency, and the fuel-oxidant inputs are arranged to minimize coking.

Abstract: A portion of an earth well bore is sealed off, and a combustible mixture of gaseous oxidizer and fuel is introduced into a sealed length of the well bore and ignited with substantial momentary pressure rise, fracturing the earth formation adjacent the well bore to increase the flow of fluid from the surrounding earth into the well. A check valve intermediate of the sealed well bore length functions to segregate the well bore into upper and lower sealed portions. By igniting a fuel gas mixture within the first sealed length, there is created a momentary high pressure wave within the sealed volume that is transmitted as a standing pressure into the second sealed volume. Successive firings of combustible mixtures in the first sealed volume create a steady pressure in the second sealed volume nearly equivalent to the peak transitory pressures realized in the first sealed volume during the individual firings.

Abstract: Process and apparatus for electrohydraulic recovery of crude oil wherein an explosive, ablative electric spark is generated at or near a subsurface oil bearing formation and which generates shock waves and hydraulic waves that radiate or propogate outwardly into the formation and cause forcible migration of oil toward adjacent collection wells. Electrical energy, which is well within the load-carrying capacity of an electrical service cable extending into the well, is stored at or near the level of the oil bearing formation by a capacitor bank. A spark gap across electrodes is broken down by discharging current from an injector capacitor bank after which a current of substantial magnitude is discharged from a main capacitor bank into the broken down spark gap, thus generating the explosive spark.

Abstract: A method and apparatus for cleaning openings in a borehole casing, slotted liner, screen or the like, cleaning subsurface earth formations and/or stimulating the flow of fluids through subsurface earth formations surrounding a borehole in which a plasma is generated adjacent the area to be treated by the gasification and ionization of a gasifiable and ionizable material, such as, water, petroleum or similar fluids and/or solids, such as, a consumable metal wire, thereby creating an intense shock wave which passes into or through the material being treated. The plasma region is created by any means adapted to gasify and ionize the gasifiable and ionizable material, such as, a high voltage, high current electrical discharge of short duration.

Abstract: A method of fabrication and the resulting structure for an economical and reliable anchor assembly to retain a conventional bridge plug within the production casing of an oil or gas well. The anchor assembly is efficiently loaded into the well and interfaced with the bridge plug via a packer and tubing, thereby eliminating the necessity of employing an expensive workover rig, which is common to many conventional well plugging techniques. The preferred method includes the step of deforming (i.e. perforating) the production casing for interlocking the anchor assembly therein. By virtue of the instant anchor assembly, a reliable plug may be installed to effectively plug back a depleted zone of an oil or gas well, while withstanding the generally large differential pressures that may be encountered at relatively deep subsurface production zones during a subsequent stimulation of the well.

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

Abstract: Natural gas deposits vented by oil or gas wells may pressurize a well beyond the capacity of installed apparatus to contain damage in the event of equipment failure, blow-out, or fire with the result that a well may flow out of control. The means and method of this invention provide for emergency action to shear a well casing together with internal piping or tubing and to seal a well if blow-out preventers otherwise provided do not prove effective. The apparatus of this invention may be self-powering.

Abstract: Discloses an improved tool and method for cutting material by expelling a jet stream of liquid chemical reactant into forceful flowing connection and chemical reaction with a designated area of the material. Applies a continuing force to a designated first stage mass of reactant to move the first mass through a designated linear distance to accelerate the first mass and thereby provide the first mass with kinetic energy. Causes the first mass to encounter and join with a second stage mass of chemical reactant to form an aggregate mass with the aggregate mass then moving at a velocity attained by the kinetic energy of the first mass, as applied to the aggregate mass, and at a rate of acceleration generated by the continued application of said force to the aggregate mass. Passes the aggregate mass through a medium adpated to heat the said aggregate reactant mass to a substantially elevated temperature.

Abstract: An explosive-containing casing is provided with a cap to which a nipple is secured. The nipple supports a rigid rod which extends the length of the casing and which in turn supports a detonation train for the explosives within the casing. An electrical connector arrangement is joined to the nipple to permit a conductive path to be established to a detonator which forms part of the detonation train. The nipple is secured to the cap in a manner which prevents the entry of water or other undesirable substances into the casing.

Abstract: A wire line well tool is connected to a fluid gun which is run into the hole along with the tool. Should the tool become stuck, the gun is actuated, e.g. electrically, to direct mud active fluid around the stuck tool and the inside of the well bore, to destroy the pressure imbalance about the tool and to exert a radial force pushing the tool toward the center of the hole to free same.

Abstract: An apparatus for retrieving drill collars in an earth boring drill string when stuck. A sub is connected between two drill collars at various points. Each sub is a cylindrical member with a reduced annular or notched area at one point that is no greater in wall thickness than the drill pipe. A locator is secured to a wire line and lowered into the drill string to the vicinity of one of the subs located above the stuck point. The locator carries an explosive charge of capacity sufficient to cut drill pipe. The locator has a pivotal dog that engages a landing in the sub. The landing is spaced above the annular area a distance selected to position the explosive charge adjacent the annular area when the dog engages the landing.

Abstract: In the several representative embodiments of selectively-operable well bore apparatus disclosed herein for dependently coupling a well tool to a suspension cable, a collapsible assembly of two or more retaining members is arranged within an enclosed chamber and operatively positioned for normally retaining upper and lower tool-support members in a position where they are tandemly coupled or interconnected. In each of the several embodiments of the invention disclosed herein, electrically-responsive securing means normally maintaining the collapsible assembly in its initial position are cooperatively arranged to be selectively failed so as to allow collapse of the retaining assembly should it become necessary to separate the cable from the well tool while it is in a well bore. Provisions are also made for admitting well bore fluids into the enclosed chamber upon collapse of the retaining assembly so as to assure release of the cable even under extreme well bore pressures.

Abstract: There is disclosed an arming and disarming device which is run into a well bore on a wireline and which is part of an explosive tool to conduct some type explosive operation in the well bore. In the disarmed configuration, the arming sub acts to separate the hot lead in the wireline from the explosive tool, to short circuit the hot and ground leads of the explosive well tool together and to connect the short circuited tool leads to ground. In one mode of use of the arming sub, hydrostatic pressure applied to the tool as it is being run into the well bore acts to move a piston inside the device. As the piston moves, the hot lead of the wireline is electrically connected to the short circuited hot and ground connections of the explosive tool. Continued movement of the piston breaks the short circuit between the hot and ground connections of the explosive tool thereby arming the tool.

Abstract: A method of producing fractures or gaps in geological formations of crystalline rocks in order to utilize the heat of the earth surrounding the gaps, comprises, drilling at least one bore into the rock, producing a pressure fluid in the bore adjacent the rock by introducing pressure gas-producing propellants into the bores to a location within the rock formation and reacting the pellants after they have been sealed off from the top of the bore and discharging the fluid pressure into the bore to put the rock under a pressure above its breaking limit so as to produce a large surface gap. The apparatus advantageously comprises a pressure gas generator which operates from a monergolic propellant which is decomposed catalytically and which includes a sealing bellows arranged around a reaction chamber at the bottom of the bore which is sealed at the upper end or to the rear and is connected with the pressure gas chamber and an outlet into the forming gap having a non-return valve therein.

Abstract: An improved chemical cutting apparatus for cutting objects in well bores such as, for example, tubing in the bore of an oil or gas well. The apparatus is properly positioned relative to the object to be cut by means of a casing collar locator, and an igniter is fired which in turn activates a gas generator. Pressure from the gas generator axially displaces a slidable piston having suitable anchor means connected thereto. Movement of the piston causes the anchor means to move into contact with the object to be cut, thereby anchoring the apparatus relative to such object. Pressure generated in the gas generator is communicated through a passageway in the slidable piston and forces a chemical cutting agent into a chamber containing a reactant. The reaction of the chemical cutting agent and reactant increases the pressure and temperature within the chamber thereby displacing along the axis a second slidable piston.

Abstract: Method of and apparatus for fracturing and creating multiple fissures in hydrocarbon impregnated rock. The invention uses a sequence of explosive charges involving a main, centrally located high velocity, shape charge shot directed out horizontally into the stratum to be fractured, and two supplemental charges of bulk explosives of a lower detonation velocity positioned above and below the main shot and simultaneously detonated following the main charge, the purpose of the sequence and the physical arrangements being to effect greater penetration of the stratum. In the preferred embodiment a metal shaped charge containing a liquid explosive is used for the centrally located main shot comprising a number of longitudinally extended tined spokes directed radially outward from a common center (note FIG. 3). The diameter of the shaped charge can be varied to fit and preferably generally fills up the diameter of the well bore.

Abstract: A chemical cutting apparatus and method for cutting objects in well bores such as, for example, tubing in the bore of an oil or gas well. The apparatus is properly positioned and an igniter is fired activating a gas generator. The resultant pressure axially displaces a slidable piston having one or more wedges pivotally connected thereto. Movement of the piston anchors the apparatus relative to the object to be cut. The pressure is then communicated through the slidable piston forcing a chemical cutting agent into a chamber containing a reactant. The resultant reaction increases the pressure and temperature thereby displacing along the axis a second slidable piston. Movement of the second slidable piston exposes radial exhaust orifices thereby allowing the reacting elements in the chamber to escape with great velocity and to contact the object to be cut. The second slidable piston is then held firmly in place.

Abstract: An earth fracturing apparatus has a casing of reactive metal containing a central, double ended charge load that is simultaneously detonated from both ends; and a pair of opposed end charges at opposite sides of the central charge load, the end charges being concavely dished toward the central charge load and having a liner of reactive metal on the dished face. The end charges are simultaneously peripherally initiated to explode with a collapsing detonation wave toward the central charge load. Void spaces between each end charge and the central charge load contain an oxidizer that may be under pressure. In a modified form of the apparatus, the end charges are omitted and the central charge load alone acts as a perforator for well pipe.

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.