Condensate accumulation in the vicinity of the gas well is known to curtail hydrocarbon production by up to 80%. Numerous approaches are being employed to mitigate condensate damage and improve gas productivity. Chemical treatment, gas recycling, and hydraulic fracturing are the most effective techniques for combatting the condensate bank. However, the gas injection technique showed temporary condensate recovery and limited improvement in gas productivity. Hydraulic fracturing is considered to be an expensive approach for treating condensate banking problems. In this study, a newly synthesized gemini surfactant (GS) was developed to prevent the formation of condensate blockage in the gas condensate reservoirs. Flushing the near-wellbore area with GS will change the rock wettability and thereby reduce the capillary forces holding the condensate due to the strong adsorption capacity of GS on the rock surface. In this study, several measurements were conducted to assess the performance of GS in mitigating the condensate bank including coreflood, relative permeability, phase behavior, and nuclear magnetic resonance (NMR) measurements. The results show that GS can reduce the capillary pressure by as much as 40%, increase the condensate mobility by more than 80%, and thereby mitigate the condensate bank by up to 84%. Phase behavior measurements indicate that adding GS to the oil–brine system could not induce any emulsions at different salinity levels. Moreover, NMR and permeability measurements reveal that the gemini surfactant has no effect on the pore system and no changes were observed in the T2 relaxation profiles with and without the GS injection. Ultimately, this work introduces a novel and effective treatment for mitigating the condensate bank. The new treatment showed an attractive performance in reducing liquid saturation and increasing the condensate relative permeability.

中文翻译：

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使用新合成的 Gemini 表面活性剂缓解冷凝水库的新方法

众所周知，在气井附近聚集凝析油会减少多达 80% 的碳氢化合物产量。正在采用多种方法来减轻冷凝水损坏并提高气体生产率。化学处理、气体回收和水力压裂是对抗凝析油最有效的技术。然而，注气技术显示出暂时的凝析油回收和气体生产率的有限提高。水力压裂被认为是处理凝析油淤积问题的昂贵方法。在这项研究中，开发了一种新合成的双子表面活性剂 (GS)，以防止在凝析气藏中形成凝析油堵塞。用 GS 冲洗近井区会改变岩石的润湿性，从而由于 GS 在岩石表面的强吸附能力而降低了保持凝析油的毛细管力。在这项研究中，进行了多项测量以评估 GS 在减轻凝析油堤方面的性能，包括岩心溢流、相对渗透率、相行为和核磁共振 (NMR) 测量。结果表明，GS 可将毛细管压力降低多达 40%，使凝析油流动性提高 80% 以上，从而减轻凝析油高达 84%。相行为测量表明，将 GS 添加到油-盐水系统中不会在不同盐度水平下引起任何乳液。而且，核磁共振和渗透率测量表明，双子表面活性剂对孔隙系统没有影响，并且在注入和不注入 GS 的情况下，T2 弛豫曲线未观察到任何变化。最终，这项工作引入了一种新的有效的处理方法来缓解凝析油。新处理在降低液体饱和度和增加凝析油相对渗透率方面表现出有吸引力的性能。