关键词: 鄂尔多斯盆地, 延长组, 储层特征, 滑塌浊积扇, 孔隙结构, 储层评价

Abstract: The characteristics of Chang 6 sandstone reservoir in Baibao-Huachi region of Ordos Basin were investigated by the data of core analysis,log,scanning electron microscope,isotope analysis,porosity and permeability analysis,acoustic emission test and mercury injection test.The pore space of reservoir mainly includes the primary residual intergranular pores and secondary intergranular pores.The microfractures and dissolution only limitedly improve the petrophysical property of reservoir and connectivity of pore throat of Chang 6 sandstone reservoir with low permeability and porosity,high displacement and saturation median point pressure,small pore throat radius,poor pores throat sorting and fine skewness.The quality of reservoir was affected by sedimentary microfacies and diagenesis.Distributary channel coarse grain sandstone of slump turbidite fan was the best microfacies for the reservoir development.The carbonate minerals and the agglutination of authigenic chlorite in the early stage of diagenesis were favorable for protection of primary pores and throats in sandstone reservoirs.According to the petrophysical properties of reservoir and pore structure parameters,Chang 6 sandstone reservoir was classified into four types.The type Ⅰ and type Ⅱ reservoirs are the available reservoirs under the current process conditions and can be taken as the major target zones for increasing reserves.

Key words: Ordos Basin, Yanchang Formation, reservoir characteristics, slump turbidite fan, pore structure, reservoir evaluation