晚三叠世延长期鄂尔多斯为陆相坳陷盆地,主要发育湖泊三角洲相沉积,油藏主要为低-特低渗透岩性油藏。研究表明,长7生烃作用形成的异常高压是石油向低渗透储层运移的主要动力,运移方式主要为幕式运移。通过成藏物理模拟手段分析不同压力条件下低渗透成藏过程及成藏特征,同时对比不同注入压力、不同充注方向下幕式成藏特征及与稳态成藏的差异。实验结果表明,无论烃源岩向上还是向下排烃,异常压力越大越有利于低渗透储层成藏,成藏效率越高,含油饱和度越高。 During the late Triassic, Ordos Basin was a continental depression basin. It mainly developed lacustrine delta deposits. The reservoirs are mainly low-ultra-low permeability lithologic reservoirs. The study shows that the abnormal high pressure formed by Chang 7 hydrocarbon generation is the main driving force for the migration of petroleum to low permeability reservoirs, and the migration mode is mainly the curtain migration. By means of reservoir physical modeling, the process of low-permeability reservoir formation and reservoir forming characteristics under different pressure conditions were analyzed. The differences between the reservoir forming characteristics and the steady-state reservoir forming under different injection pressures and different charging directions were compared. The experimental results show that whether the hydrocarbon source rocks exhausted up or down, the more the abnormal pressure is, the more favorable to the formation of reservoirs with low permeability. The higher the hydrocarbon accumulation efficiency is, the higher the oil saturation is.