SEDIMENTOLOGICAL MODELS AND SIMULATION OF SEDIMENTARY BASIN EVOLUTION: CASE STUDY OF THE PRECASPIAN DEPRESSION

Heat-flow density of the Precaspian Depression increases from north to south and from east to west. The regional thermal background is normal. Lateral and vertical variations of heat-flow density are explained by many factors. One of the most important characteristic features of the Precaspian Depression is the existance of a salt layer. For simulation of the heat-flow density distribution,the thermomechanical model of a multilayer,highly viscous fluid was used. Forma-tion and evolution of the Precaspian Depression are explained by upwelling of a mantle diapir. The existance of a dtapir is confirmed by geophysical data. Thermomechanical modelling shows that the salt layer and the salt diapirs are the positive factors of the formation and preservation of oil and gas generation zones. Thermomechanical modelling gives the possibility to locate the migration of the oil window during the process of sedimentary basin evolution. Variations of heat-flow density are explained by the characteristics of layers and the history of the basin evo-lution.