为研究不同低渗油田采收率差异的本质原因,对大庆扶余与长庆长6低渗透岩心分别进行润湿性实验、驱油实验,并利用岩心微观解剖方法求取孔隙参数并计算含油饱和度,找到影响剩余油主要因素,解释两油田采收率差异原因.实验结果表明,低渗透岩心以水湿为主,长庆油田低渗岩心采收率高于大庆油田,其中岩心2-2采收率比岩心1-1高3.9个百分点;同级别低渗岩心大庆油田孔隙表现出形状和连通状况的复杂性与不规则性;相同孔喉比、配位数、迂曲度和形状因子条件下,长庆油田低渗透岩心含剩余油孔隙比例更小,驱油效果更好,该研究为低渗透油藏的进一步开发提供理论支持.%In order to study the essential reasons of oil recovery differences in different low permeability oilfields, wettability tests and oil displacement experiments were carried out respectively for low permeability cores of Daqing Fuyu and Changqing, Chang6. Core micro-anatomy experiment was used to calculate the pore parameters and oil saturation, meanwhile, the main factors affecting remaining oil were found out. Thus reasons of oil recovery differences in two oilfields were explained. The experiment results show that, the low permeability core is mainly water-wet core, oil recovery rate of Changqing oilfield low permeability core is higher than that of Daqing oilfield, and the core 2-2 recovery rate is 3.9% higher than the core 1-1 recovery rate; For the same permeability core, the core of Daqing oilfield is more complex and irregular in shape and connectivity;Changqing oilfield has better oil displacement effect and smaller ratio of remaining oil in cores under the same pore throat ratio, coordination number, tortuosity and shape factor condition. The study provides theoretical support for further development of low permeability reservoirs.
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