沉积盆地演化的沉积学模式和模拟：前里海凹陷实例研究

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

前里海凹陷的热流密度从北向南、从东向酉增加，区域热背景值正常。诸多因素均可解释热流密度的侧向和垂向变化。前里海凹陷最重要的特征之一是盐层的存在。本文利用多层高粘滞流体的热机模式对热流密度的分布进行了模拟，并根据地馒底辟的上升解释了前里海凹陷的形成和演化。地球物理资料已证实底辟的存在。热机模拟表明，盐层和盐底辟是油气生成带形成和保存的确定性因素。热机模拟指出了沉积盆地演化过程中确定油窗迁移位置的可能性。本文还根据盐层的特征和盆地演化的历史解释了热流密度的变化。

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.