Pump apparatus including a firing head for use with a perforating gun on a tubing string.

摘要

A perforating gun (44) having no firing head and no primary explosives is attached to a tubing string (30) and the tubing string is run into a borehole. A new pump apparatus (40), having a firing head (42c), is run into the tubing string until the pump firing head is adjacent the perforating gun. The firing head in the pump apparatus detonates, firing the perforating gun. If the firing head fails to detonate, one need only remove the pump apparatus from the tubing string in order to gain access to the firing head, for repair and replacement thereof. One need not remove the tubing string to gain access to the firing head.