Abstract: An improved drag string unit is shown for use with well bore drill stem test tools of the type which have an inflatable packer and an integral pump. The drag spring unit has an outer drag spring housing and an inner mandrel slidably received within the drag spring housing. Ratchet surfaces associated with the outer housing and inner mandrel are positionable between an engaged position which allows the pump to be activated to pump up the packers and a disengaged position which prevents activation of the pump. Vent means are alignable between the inner mandrel and outer housing when the ratchet surfaces are disengaged allowing the packers to vent to the well bore.

Abstract: An emergency deflation tool intended for use in an inflatable packer system. The mechanism comprises a cylindrical axially extending member adapted to be fixed against axial movement, another hollow cylindrical member surrounding a portion of the length of said member with a vent through the wall thereof, an inflation fluid passageway, and an expendable tension sleeve joining the two members.

Abstract: A check/relief valve intended for use in an inflatable packer system. The valve comprises a hollow cylindrical longitudinally extending inner member surrounded by a spring loaded relief piston and a spring loaded check valve poppet, all surrounded by a hollow longitudinally extending outer member.