Abstract: A well perforating gun provides a full bore passage for fluids and tools through the discharged gun without increasing the normal exterior diameter of the gun. The full bore passage is disposed eccentrically within a tubular housing and the perforating guns are mounted in a longitudinally spaced array on one or more elongated strips disposed adjacent elongated slots in the wall of the housing opposite the eccentric portion of the full bore fluid passage.

Abstract: An insulation jacket and method are provided for a tubing carried perforating gun for a subterranean well. A tubular housing is secured at one end to a tubular conduit with a firing head disposed interiorly within the housing. A perforating gun is activated by the firing head and carried by the housing. A tubular heat shield is concentrically disposed around the exterior of the housing and is sealingly secured relative to an end of the housing. An annular area is defined between the interior of the heat shield and the exterior of the housing with a fluid passageway extending from the interior of the housing through the annular area and communicating with the exterior of the heat shield. The heat shield configuration may also be utilized to provide an annular wash area for washing particulate matter away from the perforating gun as it is being introduced into the well.

Abstract: An electrically operated firing piston is provided for effecting the firing of a perforating gun in a subterranean well. The electrical firing system is disposed within a hollow housing which is detachably secured to the gun and is subject to the fluid pressures surrounding the perforating gun. The electrical firing system is armed through the application of a fluid pressure to the exterior of the housing which is in excess of the well hydrostatic pressure, thereby preventing premature firing of the perforating gun before insertion at its desired position in the well. The generation of an electrical firing pulse is controlled by a microprocessor which is preset to be responsive only to a selected value of fluid pressure surrounding the control housing. Thus, the pressure surrounding the perforating gun may be reduced to a selected under-balanced condition before the firing of the gun can be effected.

Abstract: An improved shaped charge is provided for well perforating guns utilized in hydrocarbon recovery operations. An increased diameter entry hole through the casing may be formed by the shaped charge, which is particularly beneficial when perforating gravel packed formations. The explosive powder within the charge case is initiated utilizing a multi-point discharge insert which channels the shock waves from the primer cord of the gun to multiple points each radially spaced from the center line of the charge case. A plasticizer charge is utilized to fill the relatively small diameter channels formed by the insert, and an insert material having a relatively low speed of sound is preferred to prevent detonation of the explosive powder through the insert material. By changing the configuration and the size of the insert channels, the entry hole size and depth of penetration formed by the shaped charges of the gun may be easily and inexpensively modified.

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: Method and apparatus for recording data downhole in a borehole. A recorder having a data memory is lowered into a data recording position in the borehole. A signal is transmitted downhole into the borehole and the recorder is initiated to begin recording data at an ascertainable memory location of the data memory in response to a downhole stimulus produced in response to the transmitted signal. Also, a downhole recorder for use in detecting the firing of an explosive device downhole in a borehole is provided. After an attempt is made to actuate the explosive device, the recorder is retrieved to the surface where the contents of its memory are analyzed to determine whether the explosive device has been actuated.

Abstract: An explosive booster which contains a secondary high explosive material of such density that it is capable of receiving a detonation from one secondary high explosive mass, across a discontinuity, and of then detonating and transmitting the detonation to another secondary high explosive mass. The explosive booster is produced by compacting the secondary high explosive material to a density such that the booster is capable of acting as both an acceptor and donor of a detonation. The explosive booster may be used to transfer a detonation from one secondary high explosive mass to another such mass as for example in detonating a string of perforating guns within wellbores in the oil and gas industry.

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: 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: A primer mix which contains from 26 to 66 weight percent titanium and from 74 to 44 weight percent potassium perchlorate having a density of from 68 to 81 percent of crystal density such that the mix is stable at high temperature up to 525.degree. F. for more than 100 hours without degradation and requires a relatively high amount of impact energy greater than 4 ft.-lbs. in order to ignite it. Alternatively, the primer mix contains from 40 to 74 weight percent zirconium and from 60 to 26 weight percent potassium perchlorate having the above density. The primer mix is used in a percussion primer for initiating combustion or in a percussion initiator for detonating a high-order explosive, as used for example within wellbores in the oil and gas industry.