To inform cost-effective monitoring of offshore geological storage of carbon dioxide (CO₂), a unique field experiment, designed to simulate leakage of CO₂ from a sub-seafloor storage reservoir, was carried out in the central North Sea. A total of 675 kg of CO₂ were released into the shallow sediments (∼3 m below seafloor) for 11 days at flow rates between 6 and 143 kg d^-1. A set of natural, inherent tracers (¹³C, ¹⁸O) of injected CO₂ and added, non-toxic tracer gases (octafluoropropane, sulfur hexafluoride, krypton, methane) were used to test their applicability for CO₂ leakage attribution and quantification in the marine environment. All tracers except ¹⁸O were capable of attributing the CO₂ source. Tracer analyses indicate that CO₂ dissolution in sediment pore waters ranged from 35 % at the lowest injection rate to 41% at the highest injection rate. Direct measurements of gas released from the sediment into the water column suggest that 22 % to 48 % of the injected CO₂ exited the seafloor at, respectively, the lowest and the highest injection rate. The remainder of injected CO₂ accumulated in gas pockets in the sediment. The methodologies can be used to rapidly confirm the source of leaking CO₂ once seabed samples are retrieved.

为了对二氧化碳 (CO ₂ )的海上地质储存进行经济有效的监测，在北海中部进行了一项独特的现场实验，旨在模拟海底储存库中 CO _{2 的}泄漏。在 6 到 143 kg d ^-1之间的流速下，总共 675 kg CO ₂被释放到浅层沉积物（海底以下约 3 m）达 11 天。一组注入的 CO ₂和添加的无毒示踪气体（八氟丙烷、六氟化硫、氪、甲烷）的天然固有示踪剂（¹³ C、¹⁸ O）用于测试它们对 CO ₂的适用性海洋环境中的泄漏归因和量化。除¹⁸ O之外的所有示踪剂都能够归因于 CO ₂源。示踪分析表明，沉积物孔隙水中的CO ₂溶解范围从最低注入率的 35% 到最高注入率的 41%。对从沉积物释放到水体中的气体的直接测量表明，22% 到 48% 的注入 CO ₂分别以最低和最高注入速率离开海底。其余注入的 CO ₂积累在沉积物中的气穴中。一旦检索到海底样本，这些方法可用于快速确认泄漏的 CO ₂的来源。