Trabajo presentado en el 24 WGC. Disponible en CD en la biblioteca. Solicite este trabajo por email a biblio@iapg.org.ar

In Algeria south-western basins, situated in the north west of the Hoggar-Shield (fig 1), gas fields are the main discoveries. Even the proven gas reserves are important, they are trivial compared to those generated and expulsed which were evidenced by geochemical studies. To be able to prove more and more reserves, geologists have to work in both frontier and semi mature basins. In order to investigate some hypotheses, we used different approaches to understand the deformation process especially with examples in frontier basins and modelling in the more mature basins. Theselatter are more concerned by predicting the facies changes and the fractured zones, building the discrete model of fractures network, constructing the workflow from seismic to simulation of the fluidflow and finally estimating the reserves. These approaches combine several methods, including acoustic impedance, facies determination, statistics rules, often related with fractal behaviour of fault families, ante tracking analysis of fractures, and workflow from seismic to simulation