| CPC E21B 43/119 (2013.01) [E21B 43/117 (2013.01); F42B 3/02 (2013.01); F42B 3/103 (2013.01)] | 20 Claims |

|
1. A tandem sub, used to connect one or more perforating gun assemblies, comprising: a first rotational mechanism disposed within a first sleeve located at a first end, wherein the first rotational mechanism is adapted to engage with a first charge tube in a first perforating gun and allow the first charge tube to rotate freely; a second rotational mechanism disposed within a second sleeve located at a second end, wherein the second rotational mechanism is adapted to engage with a second charge tube in a second perforating gun and allow the second charge tube to rotate freely; and an outer tandem housing, wherein the outer housing is adapted to engage a first outer gun housing of the first perforating gun and engage a second outer gun housing of the second perforating gun; and a feed through bulkhead installed within a through passage, wherein the feed through bulkhead provides an electric contact between the first perforating gun and the second perforating gun while further providing a pressure seal between the first perforating gun and the second perforating gun.
|