Abstract: A perforating system for completing subsurface formations transversed by a borehole. A sub with a plurality of closed vent ports and a perforating gun are run into a borehole on the end of a tubing string. To initiate the perforating system an impact member is dropped through the tubing string. The impact member strikes a percussion firing head which initiates a detonation wave in a detonator cord. The detonation wave detonates an explosive pellet within the sub, the resulting explosion initiating a pressure wave which forcibly opens the vent ports and fluidly communicates the well bore to the tubing annulus. The detonation wave continues on in the detonator cord to actuate the perforating gun.

Abstract: Method and apparatus for automatically separating a wireline conveyed through-tubing perforating gun from a cable assembly. The gun is joined to a hollow sleeve on the cable assembly by a sub closely received in each end retained thereto by shear members. The force of the explosion upon firing the gun shears the shear members and drives the sub into the sleeve, allowing the gun to drop into the well.

Abstract: A detonation shock wave perforating system for use in perforating subsurface earth formations traversed by a borehole. The system includes a plurality of mechanically serially connected perforating gun sections, each section of which may contain a plurality of shaped charges mounted therein and a length of detonator cord. To provide coupling of the detonation shock wave between housing sections, a booster is coupled to the detonator cord and mounted proximate a shaped charge having its axis of perforation aligned along the longitudinal axis of the gun. Detonation of the shaped charge results in a jet which detonates a quantity of explosive material in the subsequent gun section the detonation of which transfers a detonation shock wave into a detonator cord, thereby detonating any explosive connected thereto. An alternate embodiment provides for coupling of the detonator wave without using a shaped charge unit.

Abstract: A detonation shock wave perforating system for use in perforating subsurface earth formations traversed by a borehole. The system includes a plurality of mechanically serially connected perforating gun sections, each section of which may contain a plurality of shaped charges mounted therein and a length of detonator cord. To provide coupling of the detonation shock wave between housing sections, a booster is coupled to the detonator cord and mounted proximate a shaped charge having its axis of perforation aligned along the longitudinal axis of the gun. Detonation of the shaped charge results in a jet which detonates a quantity of explosive material in the subsequent gun section the detonation of which transfers a detonation shock wave into a detonator cord, thereby detonating any explosive connected thereto. An alternate embodiment provides for coupling of the detonator wave without using a shaped charge unit.

Abstract: Method and apparatus for firing perforating apparatus in a borehole. A mechanically operated firing assembly is run into the borehole on the end of a cable and latched onto a perforating apparatus. Tension is pulled on the cable. At a predetermined tension force a firing rod is automatically released and as a result of force exerted by a compression spring driven into impactment with a percussion firing head to thereby detonate the perforating apparatus. Additionally, the firing assembly can be reset by application of downward force thereto.

Abstract: An explosive safe/arm system for use in a perforating gun includes a selectively rotatable member mounted intermediate a detonator and a length of detonator cord. The rotatable member includes a transversely oriented bore which is selectively rotatable into and out of axial alignment with the detonator and the detonator cord. Mounted within the bore is an explosive element for transferring an explosive detonation wave from the detonator to the detonator cord when the bore is in axial alignment.

Abstract: Method and apparatus for completing subsurface formations traversed by a borehole. A perforating gun and a firing head assembly are run into the borehole on the end of a tubing string. A percussion firing assembly subsequently is lowered through the tubing string and latches into the firing head assembly. To initiate the firing system an impact member is dropped through the tubing string. Should ignition fail to occur the percussion firing assembly and a portion of the firing head assembly can be detached and removed from the borehole. An electrical firing assembly can be lowered through the tubing string into engagement with the remaining portion of the firing head assembly and an electrical control signal used to detonate the perforating gun. Should ignition again fail the electrical firing assembly is removed leaving a perforating system having no primary explosives therein, which can be removed from the borehole by pulling the tubing string.