Abstract:
The foreland region of the Oriente Basin, which has suffered multiple stages of differential tectonic deformation under continuous EW compression, is critical for hydrocarbon accumulation and has become a predominant factor for a dynamic oil pool in the basin. This study shows an oil pool in the foredeep axis area of this basin using detailed 2D seismic sequence boundaries with a tilted oil-water contact, which is not controlled by the current simple nose structure but by a paleo-anticline trap from the earlier stage. In addition, reservoir dynamics, such factors as the current low dip formation, heavy oil property, as well as the perpendicular relationship between the NS trending nose structure and the sandstone distribution in the EW direction, are all unfavorable for hydrocarbon re-migration, which has eventually formed a metastable oil pool whose planar oil-bearing area mismatches with the current trap area.