中文摘要：

建立环境扫描电镜观察与X射线能谱定量测定烃类碳含量相结合的实验方法,表征松辽盆地南部白垩系泉头组四段致密油微观赋存特征。对致密油7口典型井17块样品168个测点的观察与分析表明,致密油主要具有2种赋存形态：油珠与油膜,以油膜为主;具有3类微观赋存空间：粒间孔、粒内孔和微裂缝,以粒间孔为主。油膜平面尺寸主要为（1~5μm）×（1~5μm）,形状不规则,以浸染粘连状形态赋存于粒间孔或微裂缝中,含碳质量百分比主要集中在40%~90%;油珠平面尺寸主要为（0.2~1.0μm）×（0.2~1.0μm）,赋存空间相对较小,含碳质量百分比主要集中在15%~30%。储集层类型与孔喉分布控制致密油赋存状态：由Ⅰ类到Ⅲ类储集层,原油含碳质量百分比及赋存油膜厚度呈逐渐减小趋势,储集层中值孔喉半径与储集层质量系数控制含碳质量百分比与油膜厚度。

英文摘要：

Combined experiment method of Environmental Scanning Electron Microscope （ESEM） and Energy Dispersive Spectroscopy （EDS） was proposed to detect tight oil occurrence in micro- and nano-pores of fight sands in Member 4 of Cretaceous Quantou Formation. Observation and analysis of 168 measurement points and seventeen samples from seven typical wells shows that the fight oil occurrences in micro- and nano-pores have two main forms： oil film and oil droplet, oil film is dominant. Intra-granular pores, inter-granular pores and micro-fractures are three kinds of micro storage space, mainly inter-granular pores. The oil films in the intra-granular pores and micro-fractures are irregular and adhesive, and the size is about （1-5 μm） × （1-5 μm）, the carbon mass percentage ofoil films are mainly 40%-90%. The size of oil droplets is （0.2-1.0 μm） × （0.2-1.0 μm）, with relatively small occurrence space. The carbon mass percentage of oil droplets are mainly 15%-30%. Reservoir types and distribution of pores control tight oil occurrence. The carbon contents and thicknesses of oil film decrease from type Ⅰ to type Ⅲ reservoirs. The carbon mass percentage and thicknesses are controlled by the median pore throat radius and reservoir quality coefficient.