DUC MINH NGUYEN
Pilots at Collins St, Arlington, TX

6295912, Oct 2, 2001

May 20, 1999

9/315692

John D. Burleson - Denton TX
Joseph A. Henke - Lewisville TX
Duc B. Nguyen - Arlington TX
James M. Barker - Mansfield TX

Halliburton Energy Services, Inc. - Dallas TX

C06C 506

89 115

Redundant explosive transfer between two explosive carrier devices is accomplished by inserting into a transfer sub or gun head a non-moveable explosive means for receiving the detonating cord which, at its first end, establishes a gap from an adjacent positive alignment insert (PAI) and wherein the length of explosive means is sufficient to assure detonation between the explosive means and the detonating cord in the event that the detonating cord shrinks due to the temperature of well applications. In the preferred embodiment of the present invention, a positive alignment insert consists of an aluminum insert housing having an annular region of imbedded explosive. The annular region of the explosive-filled insert is typically annularly lined with an aluminum sleeve for protecting the explosive within and maintaining an annular region of sufficient diameter to allow for the passage and placement of the detonating cord and booster. A positive alignment insert is inserted into both the crossover pin-and-box and the grooved tandem, or into similar transfer subs, or into gun head adapters. A stop is provided in the crossover sub, which maintains the minimum gap required to transfer a high order detonation from the explosive in the first positive alignment insert to the explosive in the second positive alignment insert.