In view of the difficult problems encountered in the development of tight oil reservoirs, using natural gas as an energy supplementary agent and adopting Huff-N-Puff (HNP) production methods have shown great application potential in the development of such reservoirs. In this study, we took the Chang-7 tight oil cores as the research object. Then, we choose natural gas (methane or the associated gas) as the injection agent and used an experimental simulation device to perform natural gas Huff-N-Puff experiment in tight cores. Finally, we analyzed the factors that affect the enhanced oil recovery factor through parallel comparative experiments. The results show that the natural gas HNP development method can effectively increase oil production based on primary depletion production, and its effective production periods were concentrated in the 1st and 2nd rounds. The flooding mechanism of natural gas HNP process focuses on interfacial aggregation and interfacial slippage of crude oil, which are conducive to enhance oil production. Moreover, when the gas agent was CH₄, it was not necessary to reserve too long soaking time during CH₄ HNP process; when the gas agent was associated gas, a longer soaking time could be appropriately reserved. Additionally, the higher pressure CH₄ injection would aggravate asphaltene precipitation, which will hinder migration of oil and gas in the pore throat of tight cores. Besides, we established the corresponding numerical model via using CMG software. Generally, the CH₄ HNP process with higher gas injection pressure had higher oil recovery. However, the ultimate oil recovery under 30 MPa gas injection pressure was lower than that under 28 MPa gas injection pressure. Therefore, the appropriate gas injection pressure should be selected in accordance with reservoir conditions during CH₄ HNP process, making its benefits overweigh its harms.

鉴于致密油藏开发中遇到的困难问题，使用天然气作为能量补充剂并采用Huff-N-Puff（HNP）生产方法已显示出在此类油藏开发中的巨大应用潜力。在本研究中，我们以长7致密油岩心为研究对象。然后，我们选择天然气（甲烷或伴生气）作为注入剂，并使用实验模拟装置在致密岩心中进行天然气Huff-N-Puff实验。最后，我们通过平行比较实验分析了影响提高采油率的因素。结果表明，天然气HNP的开发方法可以在一次消耗的基础上有效地提高石油产量，其有效生产期集中在第一轮和第二轮。天然气HNP过程的驱油机理主要集中在原油的界面聚集和界面滑移上，有利于提高原油产量。此外，当气体代理为CH时₄，在CH ₄ HNP工艺过程中不必预留太长的浸泡时间；当气体试剂是伴生气时，可以适当保留更长的浸泡时间。另外，较高压力的CH ₄注入将加剧沥青质沉淀，这将阻碍油气在致密岩心的孔喉中迁移。此外，我们使用CMG软件建立了相应的数值模型。通常，CH ₄具有较高注气压力的HNP工艺具有较高的采油率。但是，在30 MPa气体注入压力下的最终采油量比在28 MPa气体注入压力下的最终采油量低。因此，在CH ₄ HNP工艺过程中，应根据储层条件选择合适的注气压力，以使其利大于弊。