Patent ID: 7913603

Claim:
An apparatus for perforating a wellbore, comprising: a gun train formed by serially coupling a plurality of gun, the gun train including at least a first gun set and a second gun set; a tubular connector connecting the first gun set to the second gun set; an activator operatively coupled to the tubular connector, the activator being configured to detonate in response to a firing of the first gun set and to thereby generate a pressure pulse as an activation signal; a detonator associated with the second gun set, the detonator being responsive to the activation signal that is conveyed via the connector to the second gun set, the detonator firing the second gun set after receiving the initiation signal; and a vent positioned along the tubular connector, the vent being configured to admit a fluid into the tubular connector and isolate the fluid in the tubular connector from the fluid in the wellbore, wherein the activator is connected to a bottom end of the first gun set and includes a chamber wherein an energetic material is disposed; wherein the connector includes an isolated fluid, and wherein the energetic material is configured to cause a pressure change in the isolated fluid.