Abstract: A detonation system for a perforating gun assembly. The detonation system includes a tandem sub having a first end and a second opposing end. Each of the first and second ends is connected to a respective perforating gun. The tandem sub has an inner bore, and a switch housing residing within the inner bore. The tandem sub also has an addressable switch residing within the switch housing with the switch being configured to receive instruction signals from a surface by means of an electric line. The addressable switch is in communication with a signal transmission pin and a detonator pin. The detonator pin sends a detonation signal from the addressable switch to a detonator in an adjacent perforating gun. The wiring connections for the pins may be pre-assembled before the perforating guns are delivered to the field.

Abstract: A bulkhead assembly for transmitting current to a downhole tool such as a perforating gun. The bulkhead assembly comprises a tubular bulkhead body having a bore therein. The bulkhead assembly also includes an electrical contact pin. The contact pin comprises a shaft having a first end and a second end. The shaft is fabricated substantially from brass and comprises a plurality of grooves. At the same time, the bore comprises a profile for mating with and receiving the plurality of grooves. This grooved, mating arrangement increases shear strength of the bulkhead assembly. Preferably, a first end of the electrical contact pin is in electrical communication with a wire within a wellbore. The wire transmits electrical signals from an operator at the surface. The shaft comprises a conical portion proximate the first end that frictionally fits into a mating conical profile of the bore. A tandem sub having an improved electrical communication is also provided herein.

Abstract: A detonation system for a perforating gun assembly. The detonation system includes a tandem sub having a first end and a second opposing end. Each of the first and second ends connects to a respective perforating gun. The tandem sub has an inner bore, and an electronic switch assembly residing within the inner bore. A contact pin also resides within the inner bore of the tandem sub, with the contact pin having a head that extends into the electronic switch assembly and is configured to transmit instruction signals from the surface. A dart is provided near the first end of the tandem sub, with the dart having a base portion and a tip. The dart resides within an end plate, wherein the base portion has an outer diameter that is greater than an inner conduit of the end plate. The dart is configured to seal against the inner bore of the end plate in response to a pressure wave generated by detonation of charges in an adjacent perforating gun, thereby sealing off the tandem sub.

Abstract: A bulkhead assembly for transmitting current to a downhole tool such as a perforating gun. The bulkhead assembly comprises a tubular bulkhead body having a bore therein. The bulkhead assembly also includes an electrical contact pin. The contact pin comprises a shaft having a first end and a second end. The shaft is fabricated substantially from brass and comprises a plurality of grooves. At the same time, the bore comprises a profile for mating with and receiving the grooves. This grooved, mating arrangement increases shear strength of the bulkhead assembly. Preferably, a first end of the electrical contact pin is in electrical communication with a wire within a wellbore. The wire transmits electrical signals from an operator at the surface. The shaft comprises a conical portion proximate the first end that fits into a mating conical profile of the bore. A tandem sub having an improved electrical communication is also provided.

Abstract: A perforating gun orienting system. The orienting system comprises a first perforating gun and a second perforating gun, with each defining a gun barrel housing having a first end and an opposing second end. The orienting system also includes a tandem sub, with the tandem sub having first and second opposing ends defining a threaded connector, and each end having a side port configured to receive an alignment screw. A first slot resides at the second end of the first perforating gun, and a second slot resides at the first end of the second perforating gun. The slots are configured to align with the side ports, allowing the operator to access alignment screws within the side ports while aligning charges of the two guns. A method of aligning shots in a perforating gun assembly using the orienting system is also provided.