针对西峰油田庄36 井区面临单井产量下降和含水上升较快的问题，应用测井资料、岩石薄片、扫 描电镜、X 衍射、粒度分析、压汞测定等资料，对长8₁储层的岩石学特征、物性特征和孔喉特征等进行了深 入分析。结果表明：庄36 井区长8₁储层属低孔—特低孔、特低渗—超低渗储层，岩性主要为细粒岩屑长 石砂岩，发育粒间孔和溶蚀孔，孔喉结构类型属小孔隙、微细喉道型，其储层物性主要受沉积作用和成岩 作用的共同影响，造成水下分流河道和河口砂坝物性明显好于河道侧翼。根据储层物性和孔隙结构参数， 将研究区储层分为4 类，即Ⅰ 类储层为好储层、Ⅱ类储层为较好储层、Ⅲ 类储层为较差储层、Ⅳ 类储层 为差储层。研究区含水上升井主要分布在Ⅲ 类和Ⅳ 类储层中，Ⅰ 类储层的单井产量高且稳产，分类结 果符合实际。

In view of the problems of the oil yield decline and the rapid water saturation in single well of Zhuang 36 well area in Xifeng Oilfield, Ordos Basin, the logging data, rock section, scanning electronic microscope, X diffraction, grain size analysis and mercury penetration were used to analyze the lithology characteristics, physical properties, pore throat of Chang 81 reservoir. The result shows that Chang 81 reservoir belongs to low-ultra low porosity and low-ultra low permeability reservoir; the main sandstone is fine-grained lithic arkose; the reservoir mainly developed intergranular pore and dissolved pores; the pore throat structure is the type of small pore and micro throat. Sedimentation and diagenesis have impacted on the reservoir properties together, which leads that the physical properties of subsea distributary channel and mouth bar were better than that of channel frank. According to the physical properties and pore structure parameters, the reservoir in the study area can be divided into four types. The typeⅠbelongs to the best reservoirs, The type Ⅱ belongs to the good, the type Ⅲ belongs to the bad and the type Ⅳ belongs to the worst. The water producing wells mainly distributed in the reservoirs of the type Ⅳand type Ⅲ, and the oil yield in the wells of the type Ⅰ is good and stable.