Quantifying residual oil saturation (S_OR) in the inter-well region of oil and gas reservoirs is key for successfully implementing EOR solutions. Partitioning inter-well tracer tests (PITTs) has become a common method for quantifying S_OR. A new group of seven chemicals – pyridine, 2,3-dimethyl pyrazine, 2,6-dimethyl pyrazine, 4-methoxybenzyl alcohol, 3,4-dimethoxybenzyl alcohol, 4-chlorobenzyl alcohol, and 2,6-dichlorobenzyl alcohol – have been proposed as potential partitioning tracers for quantifying S_OR. Using these tracers can lead to their environmental release in the marine environment through produced water discharges, with currently limited knowledge on impacts in the marine ecosystem. The primary objective of the present study is to assess the environmental risk of discharging the tracer compounds in the marine environment. We investigated the fate and effect of these tracers in the marine environment. Biodegradability in seawater was measured to understand the fate of tracers in the marine environment. The acute toxicity of tracers was measured in terms of the percent cell viability of a rainbow trout gill cell line (RTgill-W1) and growth inhibition of the algae Skeletonema costatum. The ecotoxicological information obtained from these experiments was used in the dynamic risk and effects assessment model (DREAM) to calculate the tracers’ contribution to the environmental impact factor (EIF). The results from the DREAM simulations suggest no contribution towards EIF values from any of the tracers at the expected back-produced concentrations. Results from simulations at higher concentrations suggest that both pyrazines have the lowest environmental risk, followed by 3,4-dimethoxybenzyl alcohol, 4-methoxybenzyl alcohol, and pyridine; while both chlorobenzyl alcohols show the highest environmental risk.

量化油气藏井间区域的剩余油饱和度 (S _OR ) 是成功实施 EOR 解决方案的关键。分区井间示踪剂测试 (PITT) 已成为量化 S _OR的常用方法。一组新的七种化学品——吡啶、2,3-二甲基吡嗪、2,6-二甲基吡嗪、4-甲氧基苯甲醇、3,4-二甲氧基苯甲醇、4-氯苯甲醇和2,6-二氯苯甲醇建议作为量化 S _{OR的潜在分区示踪剂}. 使用这些示踪剂可以通过采出水排放导致它们在海洋环境中的环境释放，目前对海洋生态系统影响的了解有限。本研究的主要目的是评估在海洋环境中排放示踪化合物的环境风险。我们调查了这些示踪剂在海洋环境中的命运和影响。测量海水中的生物降解性以了解示踪剂在海洋环境中的命运。示踪剂的急性毒性是根据虹鳟鱼鳃细胞系 (RTgill-W1) 的细胞活力百分比和藻类Skeletonema costatum 的生长抑制来测量的。从这些实验中获得的生态毒理学信息用于动态风险和影响评估模型 (DREAM)，以计算示踪剂对环境影响因子 (EIF) 的贡献。DREAM 模拟的结果表明，在预期的反生产浓度下，任何示踪剂对 EIF 值没有贡献。较高浓度的模拟结果表明，两种吡嗪的环境风险最低，其次是 3,4-二甲氧基苯甲醇、4-甲氧基苯甲醇和吡啶；而这两种氯苯甲醇都表现出最高的环境风险。