1. n. [Perforating]
A blank gun section or spacer installed between the top perforating-gun assembly and firing head in a TCP operation. The safety spacer serves to position the gun assembly a safe distance below the rig floor during arming and disarming operations. The spacer should be a minimum of 10 feet [3 m] in length. In some cases, a longer safety spacer will be required to ensure that the gun assembly is positioned safely below the living quarters or other occupied areas of the drilling rig.
See: rig floor