Dresser Industries, Inc.

Thomas D Ricles

John A Barton

Richard M Ward

Robert A Turney

Donald R Forehand

Max M Murray

Gary R Domstead

A firing apparatus for use with a tubing-conveyed perforating apparatus is disclosed. Wellbore pressure applies an upward force to a first piston connected by a shearable coupling to a firing piston. At a predetermined pressure the coupling shears, allowing the first piston to move upward. The first piston moves upward until the firing piston is in fluid communication with the pressure. The firing piston is forced downward by the pressure, firing the perforating apparatus.

Subsurface well pressure actuated and fired apparatus

A downhole pressure attenuation apparatus is provided by which the explosive and hydraulic peak pressure and quasi-static pressure pulses generated by perforating gun detonation are attenuated by one or more fluid-free chambers having initially closed vent ports which are opened substantially contemporaneous with gun detonation so as to provide one or more free volume, pressure absorbing cavities. The pressure attenuation apparatus is made up of at least one fluid-free chamber and one or more pressure relief vents. Each pressure relief vent includes at least one charge port assembly having a prestressed port and an explosive filled shaped charge. The number of charge port assemblies used in each vent is determined by the surface area to be opened and the size of the vent chamber. Each of the charge port assemblies of the relief vent is operatively connected to a common explosive filled, detonating cord which forms part of the perforating gun detonating cord, or an extension thereof depending on the location of the pressure attenuating apparatus with respect to the perforating gun or guns. As the detonating cord fires, it causes each of the charge ports to sequentially fire and blow out the prestressed area of each port so as to open one or more vent holes leading to the vent chamber. The amount of explosive in each of the shaped charges of the charge ports is limited so that the detonation of the charge ports in the relief vent does not damage surrounding tubular bodies in the well.

Downhole pressure attenuation apparatus

Hydraulic cylinder apparatus, including a ram and attached piercing element is chained and secured around a perforating gun. A hydraulic cylinder is pressurized to thereby drive the piercing element through the sidewall of the perforating gun. The piercing element is tapered so that it is self-sealing during penetration of the gun sidewall. The piercing element is allowed to retract in a controlled manner so as to control the depressurization of the perforating gun.

Perforating gun pressure bleed device

A running tool and method for the use thereof in locating apparatus in a well bore includes an elongated hollow tool body and outer sleeve encircling the body; a mandrel disposed within the body and sleeve and carrying a collet on the lower end thereof which, in the running position of the tool, is enclosed within the sleeve; and a sealed chamber having a substantially incompressible fluid therein which is metered through a flange located on a tool mandrel to control the time required to move the mandrel between the running and release positions, thus controlling the force and time required for actuation of the tool to avoid inadvertent release of the well apparatus being lowered into the well bore.

Running tool for use in well bores

A unitary dual firing assembly includes a high explosive detonation cord with ends, each actuable by a different firing mechanism. The ends of the high explosive detonation cord are adjacent respective bulkhead membranes which, if broken, are effective to transfer a shockwave to detonate the high explosive cord. An intermediate section of the high explosive cord is effective to detonate perforating gun apparatus. A hydraulic firing head is located adjacent the membrane at one end of the high explosive detonating cord, while a mild explosive detonating cord is located adjacent the membrane at the other end of the high explosive detonating cord. An upper end of the mild explosive detonating cord terminates in a stem cap assembly which is responsive to an impact for detonating the high explosive cord, via a lower end of the mild explosive detonating cord. Mechanical or fluid inputs can thus be applied to reliably detonate one or the other of the firing mechanisms to trigger the perforating gun.

Dual firing system for a perforating gun

A perforating gun assembly and universal perforating charge clip apparatus in which a universal design of the charge and the charge clip include trapping of the detonating or firing cord, a lock-in position of the charge in both the raidal and transverse directions and vertical support of the shaped charge in the gun assembly.

Perforating gun assembly and universal perforating charge clip apparatus

In a preferred embodiment of the invention, a pressure actuated firing assembly for use in connection with a tubing conveyed perforating system is provided. The firing assembly is connected to a cable and lowered into engagement with the tubing conveyed perforating apparatus set within the well. The cable is removed and pressure is applied to the tubing annulus. At a predetermined pressure a shear member breaks, arming the firing assembly. Force is exerted upon an impact firing rod by a spring member causing fluid to move from a reservoir through a flow path traversing a piston attached to the impact firing rod. In one embodiment, the flow path may be restricted to provide a time delay before the impact firing rod is released whereby the force exerted by a spring forces the firing rod into a percussion firing assembly to thereby detonate the percussion firing assembly and the attached perforating apparatus. Alternatively no flow path may be provided to give instantaneous firing. Unloading members in the form of collets on the piston, prevent the spring's stored energy from being applied to the shear member. Additionally, a keeper key is inserted to prevent relative rotation of the shear member and the torsional forces which may accompany such rotation.

Apparatus for firing borehole perforating apparatus

Perforating gun automatic release mechanism wherein the perforating gun is linked to the drilling string by a coupling member. The coupling member includes a plurality of collet fingers, by which said coupling member is attached to the drilling string. The heads of the collet fingers, when inserted into the bottom of the drilling string engage a circumferential groove therein. A slidable locking sleeve, coaxially disposed within the coupling member prevents the inward radial movement necessary for the collet finger heads to disengage the groove. The locking sleeve sits on a slidable piston, which is contained inside the coupling member on top of the explosive charge which detonates the perforating gun. Upon detonation, the resulting shock wave traveling upward pushes the piston and locking sleeve to a position where the collet finger heads are free to disengage the groove, which the weight of the perforating gun then causes, dropping the gun, coupling member and all attachments away from the drilling string.

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Kingwood, TX, United States of America

Thomas D Ricles