This project will design, fabricate and test new shaped or fracture charges to more efficiently sever platform structural members. The goal is to develop a system which uses much less explosive than the current practice in offshore platform removals. Hydrodynamic code modeling will be used to evaluate the proper amount of explosive material and help design the casings. After fabrication, several charges will be tested at the Defense Research Establishment Suffield proving ground. Next, additional test charges will be tried on simulated platform structure targets at Explosive Service International’s test facility. Finally, additional charges will be used in the Gulf of Mexico during an actual platform removal. An optional task was added in the final proposal to instrument the platform used to demonstrate the explosive charge. The purpose is to make measurements of pressure waves and other explosive energy introduced into the adjacent water column and substrate around the platform leg during an actual removal.
The final report was accepted in June 2004. The general conclusions of this study are that the values of peak overpressure, impulse and energy flux density obtained from both the engineered and the bulk charges generally follow the accepted exponential shape when presented as a function of the distance from the blast charge divided by the cube root of the charge weight. These values are also closer to those computed with the Conner similitude equation than those obtained with the ARA model which can be expected based on the method used to obtain the equations and the conservative assumptions used to develop the ARA model. The limit values of 12 psi for the peak overpressure and 182 dB (re 1 uPa2-sec) for the energy flux density are obtained at half the distance for the 4.05 pounds engineered charge than the 50 pound bulk charge. Additional experiments should be performed to confirm more precisely the results obtained.