鄂尔多斯盆地中部罗庞塬地区长7储层控油性及有利区评价OA北大核心CSTPCD

The characteristics of sand body thickness,lithology,storage space,and physical properties of the Chang 7 oil layers in the Luopangyuan area of the Ordos Basin were studied using data from logging,drilling,core analysis,mercury injection and oil testing.The type of oil reservoirs in the study area and the control effect of reservoir conditions on the distribution of tight oil were discussed.Favora-ble areas were evaluated.Research result shows that the average thickness of the Chang 7 sand bodies in the Luopangyuan area is 22.6 meters,and the reservoir lithology is mainly fine-grained feldspar sandstone.The storage space is mainly composed of intergranular dis-solution pores and intergranular pores,with an average porosity of 8.04％and an average permeability of 0.36 × 10-3 μm2.The study area develops small pore-fine throat,fine pore-fine throat and micro pore-micro throat reservoirs.The oil reservoir is a len-shaped tight oil reservoir,and the tight oil exhibits quasi-continuous distribution characteristics of clusters and zones.The distribution of tight oil is mainly controlled by the thickness of sand bodies,sand-to-clay ratio,porosity,permeability,and clay content of sandstone.Fine sand-stones with large sand body thickness,low shale content,and good physical properties are conducive to the enrichment of tight oil.Four Class Ⅰ and five Class Ⅱ favorable exploration areas were obtained using the comprehensive index evaluation method.