PERFORATING GUN FIRING TOOL

摘要

A tool for activating the firing head of a perforating gun located below a packer by applying pressure to the upper well annulus while maintaining an unimpeded bore between the perforating gun and the pipe string. The tool is provided with a flow valve to prevent flow through the flow bore when closed, and a circulation valve which permits fluid flow from the upper annulus into the flow bore when open and a means of switching the valves so that when one is open the other is closed. A method of using the tool to complete a well is also disclosed.