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

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.