In the present document, we report the development of an analytical method consisting of a sequential direct-immersion/headspace solid-phase microextraction (DI-HS-SPME) followed by gas-phase chromatography and tandem mass spectrometry (GC-MS/MS) for simultaneous analysis of 4-chlorobenzyl alcohol, 2,6-dichlorobenzyl alcohol, 4-methoxybenzyl alcohol, 3,4-dimethoxybenzyl alcohol, pyridine, and 2,3-dimethylpyrazine in oilfield production waters. These compounds are under evaluation for use as phase-partitioning tracers in oil reservoirs. To the best of our knowledge, this is the first time SPME has been applied to the analysis of these compounds in production waters, or any other type of matrix where the compounds targeted are the base for a technical application. Relevant extraction parameters, such as the adsorbent phase of the fiber, direct immersion or headspace, addition of salt, temperature and time of extraction were investigated. The final optimal operation conditions consist on extracting 5 mL of sample at pH 9.0 with 1.8 g of NaCl with constant stirring during 5 minutes of DI-SPME followed by 15 minutes of HS-SPME at 70 °C using a DVB/CAR/PDMS (50/30 µm) fiber. The limits of quantification (LOQ), linearity, precision and accuracy of the method were evaluated. Analyses of the tracer compounds and recovery studies were also performed on production waters from 8 different oilfields of the Norwegian continental shelf. LOQs between 0.080 and 0.35 µg L⁻¹ were obtained. The recovery yields of the method were consistently higher than 85% and RSDs less than 13%. None of the tracer compounds was found in the real samples processed, which is consistent with one of the requirements for an artificial tracer in an oilfield: absence or constant and low background in the traced fluid. The performance of the method developed, combined with its easiness to automate, introduce a new, accurate and cost-efficient technique to process the hundreds of samples required by an inter-well tracer test.

在本文档中，我们报告了一种分析方法的发展，该分析方法包括顺序直接浸入/顶空固相微萃取（DI-HS-SPME），然后进行气相色谱和串联质谱（GC-MS / MS）用于在油田生产水中同时分析4-氯苄醇，2,6-二氯苄醇，4-甲氧基苄醇，3,4-二甲氧基苄醇，吡啶和2,3-二甲基吡嗪。这些化合物正在评估中，以用作油藏中的相分区示踪剂。据我们所知，这是SPME首次用于生产水或任何其他类型基质中的这些化合物的分析，其中目标化合物是技术应用的基础。相关的提取参数，例如纤维的吸附相，直接浸入或顶空进样，研究了盐的添加，提取的温度和时间。最终的最佳操作条件包括在5分钟的DI-SPME中不断搅拌下用1.8 g的NaCl提取5 mL pH 9.0的样品，然后在70°C下使用DVB / CAR / PDMS在15分钟的HS-SPME（ 50/30 µm）光纤。评价了该方法的定量限（LOQ），线性，精密度和准确性。还对挪威大陆架8个不同油田的采出水进行了示踪化合物的分析和回收研究。LOQ在0.080和0.35 µg L之间 在DI-SPME的5分钟内持续搅拌的同时，在70°C下使用DVB / CAR / PDMS（50/30 µm）纤维在15分钟的HS-SPME中持续搅拌8 g NaCl。评价了该方法的定量限（LOQ），线性，精密度和准确性。还对挪威大陆架8个不同油田的采出水进行了示踪化合物的分析和回收研究。LOQ在0.080和0.35 µg L之间 在DI-SPME的5分钟内持续搅拌的同时，在70°C下使用DVB / CAR / PDMS（50/30 µm）纤维在15分钟的HS-SPME中持续搅拌8 g NaCl。评价了该方法的定量限（LOQ），线性，精密度和准确性。还对挪威大陆架8个不同油田的采出水进行了示踪化合物的分析和回收研究。LOQ在0.080和0.35 µg L之间获得^-1。该方法的回收率始终高于85％，RSD低于13％。在实际处理的样品中未发现任何示踪剂化合物，这与油田对人工示踪剂的要求之一是一致的：被示踪流体中不存在本底或本底恒定且低。所开发方法的性能，加上其易于自动化的特点，引入了一种新的，准确且经济高效的技术，可处理井间示踪剂测试所需的数百个样品。