Automatic Gun Release

These include: avoiding the gun string sanding in when perforating weak sands, allowing efficient post perforation cleanup in permanent completions and eliminating the complications of dropping guns in highly deviated wells.

The pressure created by a gun after detonation causes the shifting sleeve to move and come in contact with the retainer ring. The brass retainer screws shear and allow the shifting sleeve and retainer ring to continue moving upwards freeing the finger release sub. This allows free movement of the mandrel as well. The chamber of atmospheric pressure between the mandrel and shifting sleeve, causes the mandrel to be sucked into the shifting sleeve which effectively pushes the gun out of the release sub. This dual action allows for minimal gun weight to successfully release the assembly.

The gun string and firing head then drop, exposing the wireline entry guide. The tubing pressure and rathole pressure must be equalized such that the guns string does not become hydraulically locked into the release sub.

The dropped gun string and firing head assembly has a slick fishing profile allowing it to be fished at a later time.