P511 CERCINA OIL FIELD TUNISIA – PETROLEUM GEOCHEMISTRY AND BASIN MODELLING 1 M. SAIDI Z. DEY and A. BOUHLEL ENTREPRISE TUNISIENNE D’ACTIVITES PETROLIERES Exploration Studies Department 27 Bis Av. K. Pacha 1002 Le Belvedere Tunis Tunisia. The purpose of this study based on the analytical and well data (RE 13 C for oil GC-MS determinations for biomarkers hydrocarbon composition of oils bottom hole temperature) integrated with the structural model and tectonic history is to determine the origin of the oils the timing of hydrocarbon generation and expulsion from the source rock and the most likely pathways of HC migration. Cercina