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

摘要： 根据铸体薄片、扫描电镜、碳氧同位素、物性、孔隙结构和声发射、岩心和测井分析和化验资料,对鄂尔多斯盆地白豹—华池地区长6砂岩储层特征进行的研究结果表明,该套储层储集空间以剩余原生粒间孔和次生粒间孔组合为主;储层物性较差,微裂缝对改善储层孔隙渗透性贡献不大;排驱压力和饱和度中值压力较高,孔喉半径小且分选性较差,歪度细,溶蚀作用对改善喉道连通性的效果不佳,孔隙结构参数总体较差。储层质量受沉积微相和成岩作用的综合影响,其中,由三角洲前缘滑塌形成的内-中扇较粗粒水道砂体为最有利储层发育的微相,成岩早期碳酸盐矿物和环边绿泥石胶结作用有利于部分原生孔隙和喉道的保存。利用储层物性和孔隙结构参数,将长6砂岩评价为4类储层,其中Ⅰ、Ⅱ类储层在目前的工艺技术条件下为可动用储层,是增储上产的首选储层。

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