In situ subsurface remediation has been widely used as an efficient means of cleaning up non-aqueous phase liquid (NAPL) from contaminated soils and aquifer. The use of tracer, surfactant and foam is often considered to keep track of the propagation of injected fluids in the medium, dissolve and mobilize contaminants trapped by capillary forces, and overcome the level of heterogeneity and improve displacement and sweep efficiencies. This study shows an actual remediation process to reduce NAPL within a military base in South Korea, by injecting tracer and surfactant solutions together for a duration of 10 days. The site consists of 5 m-by-5 m area with 3 m depth under the existing structure of fuel-distribution facility. The results show that (a) computer simulations can be successfully performed to history-match the production of tracer and oil species from three extraction wells during field tracer and surfactant injection tests and (b) such a successful match can be combined with identification of the major pattern of the heterogeneity in the site. With estimated foam strengths from separate column tests, this study further extends the scope to the use of surfactant–foam remediation processes to examine how foam with a reduced gas mobility (causing higher apparent foam viscosity and pressure gradient) helps mobilizing and producing more oil, hence leading to improved displacement efficiency. Surfactant/foam processes are shown to have potential in overcoming subsurface heterogeneity and thus improving overall in situ remediation performance.

中文翻译：

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使用示踪剂-表面活性剂-泡沫过程修复浅层地下环境：历史匹配和性能预测

原位地下修复已被广泛用作清除受污染土壤和含水层中的非水相液体 (NAPL) 的有效手段。示踪剂、表面活性剂和泡沫的使用通常被认为是跟踪注入流体在介质中的传播，溶解和移动被毛细管力捕获的污染物，克服不均匀性水平并提高置换和波及效率。该研究展示了通过将示踪剂和表面活性剂溶液一起注入 10 天的实际补救过程，以减少韩国军事基地内的 NAPL。该场地由现有燃料分配设施结构下的 5 m×5 m 区域和 3 m 深组成。结果表明，(a) 可以成功地进行计算机模拟，以在现场示踪剂和表面活性剂注入测试期间对来自三个提取井的示踪剂和油种的生产进行历史匹配，并且 (b) 这种成功的匹配可以与识别站点异质性的主要模式。根据独立柱测试估计的泡沫强度，本研究进一步将范围扩展到使用表面活性剂-泡沫修复过程，以检查具有降低气体流动性（导致更高的泡沫表观粘度和压力梯度）的泡沫如何帮助流动和生产更多的石油，从而提高置换效率。表面活性剂/泡沫工艺被证明具有克服地下不均匀性的潜力，从而提高整体原位修复性能。