Methods include positioning a downhole completion assembly in a tubular conduit of a downhole tubular of a hydrocarbon well. The downhole completion assembly includes a downhole sub-assembly and an uphole sub-assembly. The methods also include forming a fluid seal within the tubular conduit with the downhole sub-assembly, decoupling the uphole sub-assembly from the downhole sub-assembly, translating the uphole sub-assembly in an uphole direction, perforating the downhole tubular with the uphole sub-assembly, translating the uphole sub-assembly in a downhole direction, coupling the uphole sub-assembly to the downhole sub-assembly, ceasing the fluid seal, and translating the downhole completion assembly in the uphole direction.

An apparatus and method according to which a perforating gun includes a volume fill body. The volume fill body is positioned in the space between a charge tube and a carrier tube. The fill body occupies at least part, and sometimes all, of the free volume space between the charge tube and carrier tube thereby reducing the free volume space. In certain downhole applications, large free volume space can lead to significant reductions in wellbore pressure, causing dynamic underbalance, which is undesirable. The presence of the volume fill body prevents, or at least reduces, dynamic underbalance and its effects. Also, the volume fill body aligns the charge tube with the carrier tube, further assisting perforation.

A perforating gun and method according to which a perforating charge of the perforating gun is detonated. Detonating the perforating charge produces shock waves. In some embodiments, detonating the perforating charge also perforates a wellbore proximate a subterranean formation. After detonating the perforating charge, first and second components of a binary energetic of the perforating gun are fragmented by the shock waves, mixed by the shock waves, and activated by the shock waves to increase an internal energy of the perforating gun. In some embodiments, increasing the internal energy of the perforating gun after detonating the perforating charge delays and/or decreases wellbore pressure drawdown.

An apparatus and method according to which a perforating gun includes a volume fill body. The volume fill body is positioned in the space between a charge tube and a carrier tube. The fill body occupies at least part, and sometimes all, of the free volume space between the charge tube and carrier tube thereby reducing the free volume space. In certain downhole applications, large free volume space can lead to significant reductions in wellbore pressure, causing dynamic underbalance, which is undesirable. The presence of the volume fill body prevents, or at least reduces, dynamic underbalance and its effects. Also, the volume fill body aligns the charge tube with the carrier tube, further assisting perforation.

A perforating gun apparatus comprising a bulkhead connector located between an upper gun body thread and lower gun body thread. The bulkhead connector has seals in sealing arrangement with an upper gun body and a lower gun body with a support sleeve in contact with an inner groove support shoulder on the lower gun body. The support sleeve is radially deformable into the inner groove by a shockwave produced by firing the charges in the lower gun section. The deformation of the support sleeve attenuates the impact of the shockwave on the threaded connection. The bulkhead connector isolates the threaded connection from the pressure spike. The deformed support sleeve attenuates the shockwave from the charges firing in the upper gun section and transfers the resultant force away from the threaded connection.

Downhole completion assemblies and methods for completing a hydrocarbon well are provided. The downhole completion assemblies include an uphole sub-assembly having a perforation device, a downhole sub-assembly having a sealing structure, and a coupler configured to repeatedly couple and decouple the downhole sub-assembly and the uphole sub-assembly to one another. The methods include positioning a downhole completion assembly in a tubular conduit of a downhole tubular of a hydrocarbon well. The downhole completion assembly includes a downhole sub-assembly and an uphole sub-assembly. The methods also include forming a fluid seal within the tubular conduit with the downhole sub-assembly, decoupling the uphole sub-assembly from the downhole sub-assembly, translating the uphole sub-assembly in an uphole direction, perforating the downhole tubular with the uphole sub-assembly, translating the uphole sub-assembly in a downhole direction, coupling the uphole sub-assembly to the downhole sub-assembly, ceasing the fluid seal, and translating the downhole completion assembly in the uphole direction.

A technique facilitates mitigation of shock loads. Subterranean communication systems may comprise components susceptible to various shock loads. A shock mitigation system is physically coupled with the subterranean communication system to mitigate such shock loads. The shock mitigation system comprises components selected to enable reduction of various effects of shock loads, e.g. shock loads resulting from perforating procedures, which could otherwise be detrimental to continued operation of the subterranean communication system.

A method and apparatus according to which a perforating gun includes a first detonation train and a second detonation train. The first detonation train is detonable to perforate a wellbore proximate a subterranean formation. The first detonation train includes a first detonating fuse and a perforating charge ballistically connected to the first detonating fuse. The second detonation train is detonable to increase an internal energy of the perforating gun after detonation of at least a portion of the first detonation train. The second detonation train includes a second detonating fuse ballistically connected to the first detonating fuse. In some embodiments, increasing the internal energy of the perforating gun after detonating the at least a portion of the first detonation train decreases and/or delays pressure drawdown within the wellbore.

A single-trip method and system for perforating casing allows displacement of a heavier completion fluid from the perforation zone by a lighter formation-compatible treatment fluid without the need for an extended rat hole or repositioning the working string. The perforating system includes bridge subs located above and below a perforating gun. The bridge subs bypass treatment fluid around the gun through one or more conduits located along the exterior of the gun into a discharge flow port located immediately below the lower bridge sub. The system may be hydrodynamically designed to maintain efficient fluid displacement characteristics of the discharge flow port. The external conduits are positioned to not interfere with perforation operations and may include parallel conjoined tubes. The perforating system may be lowered to a perforation position in the wellbore, and treatment fluid pumped through the discharge flow port to displace completion fluid prior to perforation operations.

Provided are compositions, methods, and systems that relate to use of viscoelastic surfactant gels in well perforation. A method for well treatment comprising: introducing a viscoelastic surfactant gel into a wellbore; and forming one or more perforation channels in an interval of the wellbore while the viscoelastic surfactant gel is disposed in the wellbore. A method for well treatment comprising: introducing a viscoelastic surfactant gel into a wellbore over an interval of the wellbore to be perforated; disposing a perforating gun into the wellbore such that the viscoelastic surfactant gel is disposed between the perforating gun and a casing of the wellbore; and forming one or more perforation channels in the interval of the wellbore. A downhole perforating system comprising: a perforating gun disposed at a distal end of a work string; and a viscoelastic surfactant gel.