超低渗油藏储层物性差、非均质性强、注采比高、地层压力保持水平低，部分油藏驱替方案构建难度大、注入水易于沿裂缝窜留，因而水驱波及体积小且采收率低。为了解决该难题，开展了长8段超低渗油藏注采调整政策综合研究。首先对单砂体的测井识别标志、叠置样式、侧向接触模式和见水见效特征进行精细刻画，裂缝、高渗带对水驱有双重作用。通过微观可视化仿真模型对不同孔隙结构下剩余油赋存模式进行研究，超低渗油藏剩余油分布模式主要有分散状及连片状形式，其分布受孔喉尺寸、并联结构、驱替压差、毛管力等因素影响。最终将研究结果应用于地质建模，指导油藏小层精细注采调整，确定了周期注水方式和周期，形成了超低渗油藏全生命周期精细注采技术。将该技术指导华庆、环江油田超低渗油藏注采调整1.5万次左右，采油速度平均增加0.2%、缓解油藏递减1.2%、年均累计增油5万t以上。

In response to the poor physical properties, strong heterogeneity, high injection production ratio, and low formation pressure of ultra-low permeability reservoirs in the Ordos Basin, as well as the contradiction between the difficulty of establishing displacement in some reservoirs, the presence of injected water flowing along fractures, the small volume of water flooding and low recovery rate, the logging identification marks, stacking style, lateral contact mode, and water breakthrough characteristics of single sand bodies are first finely characterized. Secondly, a microscopic visualization simulation model was used to study the remaining oil occurrence patterns under different pore structures. Finally, the development of fractures and high permeability zones in the study area, as well as their water drive patterns, were summarized. The research results are ultimately applied to geological modeling to guide the fine injection and production adjustment of small reservoirs, determine the cyclic injection system and cycle, and construct a full life cycle fine injection and production technology for ultra-low permeability reservoirs. Guiding the injection and production adjustments of ultra-low permeability reservoirs in Huaqing and Huanjiang oilfields for about 15 000 times, with an average increase in oil recovery rate of 0. 2% , alleviating reservoir decline by 1. 2% , and an annual cumulative increase of over 50 000 tons of oil.