华152 井区外围是鄂尔多斯盆地城华油田重要的产油和扩建井区，其主力产层为延长组长3 油层组。研究该区长3 储层的孔隙发育特征，对于石油储层评价，乃至认识油藏的形成和预测油藏分布具有重要的意义。文中通过薄片观察、扫描电镜及孔喉图像分析得出，研究区长3 储层砂岩中与油气流体活动有关的孔隙以残余原生粒间孔为主，其次为各种次生溶蚀孔隙；喉道以片状为主，其次为缩颈型和管束状。同时，发现砂岩的沉积环境与孔隙特征具有一定的相关性，水下分流河道储层砂岩以中—细喉为主，而河口砂坝储层砂岩以中喉居多。利用压汞法对长3 储层毛细管压力特征进行了分析，发现孔喉分布既有较复杂的单峰型，也有简单的双峰型，毛细管压力曲线大致可分为Ⅰ，Ⅱ，Ⅲ 3 种类型。长3 储层孔喉分选程度总体相对较好，孔喉体积差别较大。总体上，砂岩孔隙结构及分布特征反映出该区长3 储层具有较好的储集能力，有利于油气聚集成藏。

The Outskirt area ofHua 152 well field is important oil producing region and major expansion well field, and Chang 3 reservoir is its principal producing formation. The research on the pore characteristics of Chang 3 reservoir is significant for the reservoir evaluation, the cognition of reservoir forming and reservoir distribution prediction. Based on thin section observation, scanning electronic microscope and pore throat image analysis, it is believed that residual primary intergranular pore is the main pore type in Chang 3 reservoir, followed by all kinds of secondary dissolution pores. Lamellar throat is the main type of throat, and secondly it is constriction pore and tubular throat. The pore features of the sandstone are related to the sedimentary environment. Medium to fine throat chiefly distributes in the sandstone reservoir of subaqueous distributary channel, and mediumthroat mainly distributes in the sandstone reservoir of river mouth bar. By means of mercury intrusion method, capillary pressure characteristics of Chang 3 reservoir are analyzed, and it is found out that there are complicated unimodal model and simply bimodal model of pore throat distribution. Capillary pressure curve can be approximately divided into typesⅠ, Ⅱ and Ⅲ. Pore throat sorting degree of Chang 3 reservoir is better on the whole, there is large difference among volume of pore throats. In brief, standstone pore structure and its distribution characteristics demonstrate that Chang 3 reservoir of the study area has fairly accumulation capability and is favorable for reservoir formation.