FIELD OF THE DISCLOSURE

The disclosure relates generally to wellbore operations. Specifically, safer and more reliable downhole perforating systems and methods of use are described.

BACKGROUND OF THE DISCLOSURE

In a typical oil and gas operation, well casing is installed in a borehole drilled into subsurface geologic formations. The well casing prevents uncontrolled migration of subsurface fluids between different well zones, and provides a conduit for installing production tubing in the well. The well casing also facilitates the running and installation of production tools in the well.

It is common practice in the completion of oil and gas wells to perforate the well casing and the surrounding formation to bring a well into production by the downhole detonation of shaped charges, i.e. explosives of high velocity. A gun-assembled body containing a plurality of shaped charges is lowered into a wellbore and positioned opposite the subsurface formation to be perforated. Electrical signals are then passed from a surface location through a wireline to one or more blasting caps located in the gun body, thereby causing detonation of the blasting caps. The exploding blasting caps in turn transfer a detonating wave to a detonator cord which further causes the shaped charges to detonate. The detonated shaped charges form an energetic stream of high pressure gases and high velocity particles which perforates the well casing and the adjacent formation to form channels. The hydrocarbons and/or other fluids trapped in the formation flow into the channels, into the casing through the orifices cut in the casing, and up the casing to the surface for recovery.

Due to the explosive and dangerous nature of shaped charges, great care must be taken to assure safety in assembly and operation of the perforating guns while maintaining their reliability. As such, many industrial improvements have been made to prevent premature ignition before the perforating gun is properly positioned.

For instance, accidental detonation of explosive devices has been avoided by transferring tools to the well site in an unarmed condition. The arming step is then performed at the well site.

Safety regulations have also been enacted to reduce the amount of manual handling of the perforating guns on a drill rig or handling by inexperienced persons. The American Petroleum Institute (API) developed guidelines for safe handling of the explosives, including the suspension of all surface operations during the arming and connection of the gun sting.

Unfortunately, many of the devices that are designed to increase safety and reliability also add new levels of complexity to the perforating gun. This, in turn, increases the risk of human error and handling issues.

Thus, what is needed in the art are methods and devices to improve the safety and reliability of the perforating guns without making the guns or their assembly more complex. Although wellbore perforations are quite successful, even incremental improvements in technology can mean the difference between safe and cost-effective production and unintended surface explosions.

SUMMARY OF THE DISCLOSURE

The present disclosure includes any of the following embodiments in any combination(s) of one or more thereof:

In an embodiment of the present disclosure, a universal initiator for a perforating gun is provided. The initiator comprises an upper module having a detonator and a detonating cord affixed thereto. The initiator further comprises a lower module adapted for engagement of a wiring harness. The initiator further comprises a printed wiring assembly (PWA) between the upper module and the lower module.

In another embodiment of the present disclosure, the initiator comprises a multi-piece housing, a universal adaptor for engaging a loading tube affixed thereto at the downhole end of the housing, and a universal bulkhead at an up-hole end to engage a firing head. The multi-piece housing has an upper and lower module, each module having an inner and outer surface and an up-hole and downhole end, as well as upper and lower covers that attached to the outer surface of the upper and lower module. A detonator is installed during the manufacturing process and affixed to the outer surface of the upper module. A printed wiring assembly is between the upper and lower module. The printed wiring assembly has a least one microprocessor that is connected to the detonator and an RCA connector for connecting the initiator to the firing head.

This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

