应用氩离子抛光-场发射环境扫描电子显微镜对其孔隙特征进行描述,统计不同孔隙孔径分布范围,同时结合其样品粘土矿物成分、含量测试实验,分析不同孔隙成因。针对18口取芯井,共399.04m岩心进行样品采集,通过对鄂尔多斯盆地延长组长7段典型陆相页岩储层105块岩石薄片样品及83块铸体薄片样品进行测试分析的结果表明,鄂尔多斯盆地延长组陆相页岩油气地层,有机质演化程度中等,RO在0.6%~1.3%之间,其孔隙类型主要分为基质孔隙和有机质孔隙两大类,其一为基质孔隙,包括有原生晶(粒)内、间孔及晶间隙和次生的晶间溶孔,主要是与蒙脱石转化为I/O混层或伊利石时脱水形成的微孔隙,同时见有少量经过溶蚀孔形成的晶间溶孔;其二为有机质孔隙,主要是在有机质不同演化阶段排烃形成的出油孔和出气孔,及演化到大规模成气阶段的“气孔群”。孔隙尺度统计结果表明,该套陆相页岩油气地层的微孔隙大小主要分布在0.02μm~100μm之间。基质孔隙尺度分布较宽,平均尺度相对较大,微米级孔隙占约23%左右,纳米级孔隙占约77%;有机孔隙尺度相对较小,主要分布在20nm~750nm之间,以纳米级孔隙为主。分析认为鄂尔多斯盆地延长组陆相页岩气地层微孔隙体系的形成与(泥)页岩的成岩演化及有机质的热演化成熟度有关,不同演化阶段形成不同微孔隙类型。 The pore characteristics were characterized by scanning electron microscopy (SEM) and field emission scanning electron microscopy (SEM). The distribution of pore size distribution was calculated. The clay mineral composition and content of the samples were measured and the origin of different pores was analyzed. A total of 399.04m cores were sampled from 18 coring wells. Through the test and analysis of 105 rock samples and 83 samples of castings in the typical 7-member shale reservoir of Yanchang Formation in Ordos Basin, The lithofacies of continental shales in the Yanchang Formation of Yanchang Formation in the Ordos Basin are medium-scale with RO ranging from 0.6% to 1.3%. Their pore types are mainly divided into two types: matrix pores and organic pores, one of which is the matrix pore, Intergranular and intercrystalline interstitial and intergranular intergranular dissolved pores are mainly micro-pores formed by the dehydration of montmorillonite into I / O mixed layer or illite, meanwhile, a small amount of dissolved pores The second is organic porosity, which is mainly the oil hole and air outlet formed by hydrocarbon expulsion in different evolution stages of organic matter, and the “stoma group” evolved to large-scale gas-forming stage. The statistical results of pore scale show that the micro-pore size of this continental oil and gas formation is mainly distributed between 0.02μm and 100μm. The pore size distribution of matrix is ​​wide and the average scale is relatively large. Microporous pores occupy about 23%, and nano-scale pores occupy about 77%. The organic pores are relatively small in size and are mainly distributed in the range of 20 nm to 750 nm, Mainly. It is concluded that the formation of micro-pore system in the continental shale gas formations of Yanchang Formation in Ordos Basin is related to the diagenetic evolution of (shale) shale and the thermal evolution maturity of organic matter, with different microporosity types formed in different evolution stages.