雅布赖中生代叠合盆地特征及勘探方向

Characteristics of the Yabulai Mesozoic Basin and its exploration strategy

雅布赖盆地位于河西走廊中段阿拉善地块北部,为一中生代叠合型盆地,主要经历了早、中侏罗世断陷成盆、晚侏罗世挤压隆升、早白垩世断陷成盆和晚白垩世挤压逆冲四个演化阶段。早、中侏罗世拉张断陷阶段控制了下侏罗统烃源岩及储集相带的分布,晚侏罗世的整体隆升形成局部反转构造圈闭。早白垩世拉张断陷成盆演化阶段促进了侏罗系烃源岩成熟演化,晚白垩世挤压逆冲阶段在盆地南缘发生基底卷入型逆冲活动,形成了一系列构造圈闭,是盆地油气聚集的主要时期。小湖次凹构造—岩性目标和南部冲断带小湖—红茨梁段构造目标是雅布赖盆地油气勘探的重点方向。

Located in the north of Alxa massif in the middle part of Hexi Corridor,the Yabulai is a Mesozoic superimposed basin.It mainly experienced four evolution stages:basin formation in early and middle Jurassic,compression uplift in late Jurassic,basin formation in early Cretaceous,and compression thrust in late Cretaceous.The distribution of source rocks and reservoir facies belts in Lower Jurassic was controlled by the extensional fault depression stage of Early and Middle Jurassic,and the overall uplift of Late Jurassic resulted in localinversion structural traps.The basin-forming and evolution stages of the Early Cretaceous extensional fault depression promoted the maturation and evolution of Jurassic source rocks,and the basement involvement thrusting occurred in the southern margin of the basin during the compression and thrust stages of the Late Cretaceous,forming a series of structural traps,which is the main period of hydrocarbon accumulation in the basin.Structurallithological targets of Xiaohu subsag and structural targets of Xiaohu-Hongciliang in the southern thrust belt are key objectives of the hydrocarbon exploration in the Yabulai Basin.