Abstract: An end plate for securing and orienting a charge tube within a downhole-perforating gun. The end plate includes apertures for receiving locating tabs on the end of the charge tube to ensure the end plate is affixed to the charge tube in a specific orientation. The end plate includes an alignment tab that mates with a corresponding alignment groove in the perforating gun barrel for ensuring insertion of the charge tube into the perforating gun barrel in correct orientation to ensure the perforating charges exit through pre-designed scallops in the perforating gun barrel. A series of apertures may be present within the end plate to allow usage with one of a variety of sizes of charge tube. The end plate may include manipulation spaces along the circumference of the end plate to allow the end plate to be properly positioned or retrieved. The end plate may include an attachment system for attachment of an initiating device.

Abstract: A coupling device is described in which a connector is attached to each device to be coupled. The connectors are attached by way of collet fingers biased into recesses within the opposing connector by a slideable collar. The slideable collar may be locked into a coupling position by a locking mechanism such as a setscrew. To release the locking mechanism, a fluid pressure is applied to overcome the locking mechanism and drive apart the connectors.

Abstract: A firing head sub for use in explosive well perforation is described. The firing head initiates the firing of a charge within a downhole perforating gun, and also releases the firing head and perforating gun from the tubing string upon firing so as to avoid clogging of the perforating gun with sand and jamming of the perforating gun downhole. The firing head and perforating gun will only be released upon detonation of the charge. This is ensured by a feedback loop that returns spent detonation gas to the firing head to shift a sleeve, thereby unbiasing the firing head latches from their engagement with the tubing string connector, thereby releasing the firing head from the tubing string.