Abstract:

By focusing on Xinglongtai buried hills in the western sag of Liaohe depression,this article summarizes the distribution characteristics of multileveled interior reservoirs in metamorphic buried hills,analyzes the controlling factors,such as lithologic characteristics,tectonic movements,source rocks,oil charging "window" and sealing system,upon the formation of interior reservoirs in buried hills,and establishes hydrocarbon accumulation pattern of interior reservoirs in metamorphic buried hills.It concludes that the development of fractures is jointly controlled by tectonic movements and dominant lithology;the existence of various lithologic combinations in me-tamorphic buried hills makes it possible for an alternate distribution of reservoirs and barriers;and the lateral charging "window" for oil migration is the key to the formation of interior reservoirs and its extent determinates the vertical range of oil/gas pools.These understandings effectively guide the exploration in deep buried hills in Liaohe depression.

Key words: metamorphic rock, dominant lithology, tectonic movement, fractured reservoir, composite hydrocarbon-generating system, interior reservoir in buried hills, Liaohe Depression