Control Factor and Reservoir-Forming Pattern of Lithologic-Stratigraphic Reservoirs in Raoyang Sag

Raoyang sag is a typical continental rifted sag richest in hydrocarbons in Jizhong depression and has good geological conditions for forming lithologic-stratigraphic reservoirs. Researches indicate that the forming and distribution of lithologic-stratigraphic reservoirs in this sag are controlled by four control factors,among which the structural setting and paleogeomorphology control extension of sedimentary system and sand body; the basement of carbonate platform and strong tilted block movement in Cenozoic and the sedimentary-reservoir facies belt and trough rich-in oil control definitively the distribution and abundance of lithologic-stratigraphic reservoirs. The reservoir-forming patterns of lithologic-stratigraphic reservoirs are established on the basis of reservoir-forming characters of steep belt,trough belt,central buried-hill structural belt and slope belt within the sag.