Taking the tight oil of the Zhongnan sag in the Ordos Basin, Jimusar sag in the Junggar Basin and Qingxi sag in the Jiuquan Basin as study objects, based on field survey, dissection of tight oil reservoirs, sample test, modeling experiment and comprehensive analysis, this study reveals that the tight oil accumulates at start-up pressure, advances under differential pressure, diffuses at alternating fast and low speeds, charges in stepped large area and migrates rapidly through fractures, and enriches in dominant fractures and pores. The root cause of ladder-like charge is the multiple scales of pores. The widespread source rock with high hydrocarbon generation intensity is the material basis for tight oil enrichment; the dominant source reservoir assemblage is the basic unit for tight oil enrichment; fractures and beddings are conducive to local rapid migration of tight oil; fractures and pores work together to control the enrichment of tight oil. Two typical accumulation models of tight oil are established, namely “source reservoir in coexistence, four optimal factors controlling enrichment around central area, and large-scale continuous distribution” for a large freshwater lake clastic rock basin and “source reservoir integration, four optimal factors controlling enrichment, central area distribution, small in size but high in enrichment degree “ for a small saline lake diamictite depression.

以鄂尔多斯盆地中南凹陷，准oil尔盆地吉木萨凹陷和酒泉盆地青溪凹陷的致密油为研究对象，在野外调查，致密油储层解剖，样品试验，建模实验和综合分析的基础上，这项研究表明，致密油在启动压力下聚集，在差压下前进，以快速和低速交替扩散，在阶梯状大面积中充注，并通过裂缝迅速迁移，并富集主要的裂缝和孔隙。阶梯状电荷的根本原因是孔隙的多个尺度。高烃生成强度的广泛烃源岩是致密油富集的物质基础。主导油藏组合是致密油富集的基本单元。裂缝和层理有利于致密油的局部快速迁移；裂缝和毛孔共同作用，以控制致密油的富集。针对大型淡水湖碎屑岩盆地，建立了两种典型的致密油成藏模型，即“共存源储，控制中心区富集的四个最优因子和大规模连续分布”和“源储整合，四个最优因子”。小型盐湖黑amic石凹陷的“控制富集，中心区域分布，规模小而富集度高”。