鄂尔多斯盆地西部陆内前陆盆地的晚期发育与油气聚集

Later Stage Development and Hydrocarbon Accumulation of Intracontinental Foreland Basin in Western Ordos Basin

鄂尔多斯西部前陆盆地结构主要出现于晚侏罗世芬芳河期,新生代以来遭受改造并定型,形成现今地震剖面或沉积剖面上所见到的具有类似于前陆盆地的构造特征,但其与典型前陆盆地具有明显的区别。它形成和定型的时间主要在中生代末期到新生代以来,它促进了盆地靖边—乌审旗气田区的形成,也成为鄂尔多斯本部晚期成藏的重要动力来源。同时,它形成和主要发育时期与鄂尔多斯盆地天然气的主生烃期一致,也促成了盆地西部不同类型有利圈闭的形成。

Foreland basin structure in western Ordos mainly appeared in Fenfanghe Stage in Late Jurassic.It was regenerated and fell into a pattern,forming the structural characteristics of similar to foreland basin,which can be seen on current seismic cross section or sedimentary cross section.But it is different from typical foreland basin.Its time of formation and patterning is from the end of Mesozoic to after Cenozoic.It promoted the formation of Jingbian-Wushenqi Gas Field area,and was important driving source of later reservoir formation of Ordos area.Meanwhile,its main development time was accordant with the main gas generation time in Ordos Basin,and promoted formation of different types of favorable traps in Western Ordos Basin.