Department of Petroleum Engineering, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
Center for Integrative Petroleum Research, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
Molecules. 2020 Jul 2;25(13):3030. doi: 10.3390/molecules25133030.
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 T 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.
凝析油在气井附近的聚集会导致烃类产量减少高达 80%。为了减轻凝析油的损害并提高天然气的产量,人们采用了许多方法。化学处理、气体回收和水力压裂是应对凝析油堵塞最有效的技术。然而,注气技术仅能暂时回收凝析油,对提高天然气产量的效果有限。水力压裂被认为是一种昂贵的处理凝析油堵塞问题的方法。在本研究中,开发了一种新合成的双子表面活性剂(GS),以防止凝析气藏中形成凝析油堵塞。用 GS 冲洗近井地带将改变岩石润湿性,从而由于 GS 在岩石表面的强吸附能力而降低保持凝析油的毛管力。在本研究中,进行了多项测量来评估 GS 在减轻凝析油堵塞方面的性能,包括岩心驱替、相对渗透率、相态和核磁共振(NMR)测量。结果表明,GS 可以将毛管压力降低多达 40%,将凝析油的流动性提高 80%以上,从而将凝析油堵塞减轻多达 84%。相态测量表明,在不同盐度水平下,向油盐水体系中添加 GS 不会引起任何乳状液。此外,NMR 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 GS 前后,T 弛豫曲线没有观察到任何变化。最终,这项工作提出了一种新颖有效的处理方法,可用于减轻凝析油堵塞。该新处理方法在降低液体饱和度和提高凝析油相对渗透率方面表现出了有吸引力的性能。