Abstract Hydraulic fracturing technology is the most effective stimulation method to develop hydrocarbons in tight reservoirs, but the invading of fracturing fluid into the reservoir matrix often causes permeability damage, resulting in reducing the effectiveness of the stimulation treatments. Therefore, in this paper, for tight cores with permeability of 0.10 × 10−3μm2, 0.05 × 10−3μm2 and 0.01 × 10−3μm2, the damage laws were studied through flow experiments. The results are as follows: taking cores with the permeability of 0.05 × 10−3μm2 as an example, the damage rate of water-sensitivity damage, water-locking damage, and solid-phase damage were 12%, 10% and 9%, respectively, indicating that water-phase damage was the major damage; as the initial core permeability decreases, the water-sensitivity damage rate and water-locking damage rate increase, while the solid-phase damage rate decreases slightly, but the total damage rate increases. In addition, the control methods of liquid-phase damage caused by the invading fracturing fluid were studied, and the results are as follows: increasing the flowback volume is effective to control water-locking damage, but has no obvious effect to water-sensitivity damage; for polymer clay stabilizer, the relative molecular weight (when changing from 1 × 104 to 11 × 104) affect the effect of water-sensitivity damage (the permeability damage rate increased by 141% for cores with the permeability of 0.05 × 10−3μm2), indicating that the molecular weight of clay stabilizer should be fully considered; for surfactant-based cleanup additive, when the oil/water interfacial tension (IFT) was reduced from 1.26 mN/m to 0.26 mN/m, the core damage rates were reduced by 44%, 36% and 34%, respectively, indicating that the reduction of IFT was beneficial to water-locking damage control. This paper is useful for further studying the damage law of fracturing fluid to tight reservoir and the control method of water-phase damage, and provide some references for the efficient development of tight hydrocarbon resources.

中文翻译：

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压裂液对致密储层基质的危害及控制方法研究

摘要 水力压裂技术是致密储层油气开发最有效的增产手段，但压裂液侵入储层基质往往会造成渗透率破坏，降低增产措施的效果。因此，本文针对渗透率为0.10×10-3μm2、0.05×10-3μm2和0.01×10-3μm2的致密岩心，通过流动实验研究了损伤规律。结果如下：以渗透率为0.05×10−3μm2的岩心为例，水敏损伤、水锁损伤、固相损伤的损伤率分别为12%、10%和9%，分别说明水相损伤为主要损伤；随着初始岩心渗透率降低，水敏破坏率和水锁破坏率增加，固相损伤率略有下降，但总损伤率增加。此外，研究了压裂液侵入造成液相损伤的控制方法，结果如下：增加返排量对控制水锁损伤有效，但对水敏损伤无明显影响。 ; 对于聚合物粘土稳定剂，相对分子量（从1×104变为11×104时）影响水敏损伤效果（渗透率为0.05×10−3μm2的岩心，渗透率损伤率增加141%） ，说明要充分考虑粘土稳定剂的分子量；对于基于表面活性剂的清洁添加剂，当油/水界面张力 (IFT) 从 1.26 mN/m 降低到 0.26 mN/m 时，核心损伤率分别降低了44%、36%和34%，表明IFT的降低有利于水锁损伤控制。该论文有助于进一步研究压裂液对致密储层的破坏规律和水相破坏的控制方法，为致密油气资源的高效开发提供参考。