The SCOPE 3 model (Shell Code for Overpressure Prediction in gas Explosions) has been developed to predict the overpressures which could be generated by gas explosions in vented enclosures, such as offshore modules. SCOPE 3 attempts, wherever possible, to model the underlying physical processes in an explosion. This phenomenological approach gives greater confidence in predictions for full-scale events than methods based simply on correlations of experimental data. (C) 2000 Shell International Oil Products.