鄂尔多斯西缘前陆盆地构造热事件与油气运移

应用构造学、岩石学、矿物学和古热史等研究方法,证实鄂尔多斯西缘前陆盆地在中生代晚期发生了强烈的构造热事件活动。生烃史表明,这次事件与烃源岩的主生烃期相吻合,它不仅使岩石产生大量裂缝,为烃源岩排烃和油气二次运移提供了极好通道,而且还产生强大动力,促进烃源岩排烃和驱动油气二次运移。结果,这次事件显著提高了烃源岩排烃率和油气运移效率,并控制了油气运移方向和分布规律。中生代晚期的构造热事件不仅是重要的生烃事件,也是重要的成藏事件。

Tectono-thermal event in west foreland basin of Ordos and its effects on oil-gas migration

The tectono-thermal event was demonstrated to have taken place in the west foreland basin of Ordos in the Meso-zoic by using the methodology related to tectonics, lithology, mineralogy and palaeothermal evolvement history. It was coe-val with the main time of hydrocarbon generation of source rocks in the basin. Moreover, this event not only produced agreat deal of fissures in source rocks, which provided good passages for hydrocarbon excluding from those rocks and oil ga-ses migrating within layers, but also served as a powerful drive to the oil gas migration. As a result, both of excluding andmigrating rates of hydrocarbon were increased greatly, and the migration and distribution of oil gases manifested certainlaws. This suggests that the tectono-thermal event acted as an important hydrocarbon-generating process as well as an im-portant oil-gas storing one.