Abstract

Successful decommissioning of subsea oil and gas infrastructure requires a safe and effective approach to assess and manage waste products. These products, often present as scale on internals of pipelines, include naturally occurring radioactive materials (NORM) and trace metals. Understanding the potential effects of these contaminants on marine fauna is crucial to managing global decommissioning. This review is composed of two aspects: 1) a systematic review was conducted to synthesize literature on all contaminants associated with decommissioned offshore structures and the effects of NORM contaminants on marine organisms; 2) a critical review of current environmental regulations for decommissioning and characterization of petroleum scale and NORM components. Studies defining the chemical and radiological contaminants associated with decommissioned structures were very limited. The main source of contaminants was identified from offshore platforms, with none from subsea structures. Only three studies measured variable chemical effects of radium to organisms from scale materials in subsea oil and gas infrastructure. No studies measured effects on organisms from other NORM, such as lead-210 and polonium-210. Currently, there are no international regulations on subsea pipeline closure, with NORM being underreported and not addressed in environmental impact assessments. This review highlights research gaps from environmental monitoring and characterization of NORM associated with decommissioned structures. Key recommendations for future research include characterizing NORM scale and assessing effects of scale to marine organisms through direct organism exposure experiments. This review emphasizes the need to incorporate ecotoxicology into environmental risk assessment for offshore petroleum decommissioning.

摘要

海底石油和天然气基础设施的成功退役需要一种安全有效的方法来评估和管理废物。这些产品通常以管道内部结垢的形式出现，包括天然存在的放射性物质 (NORM) 和微量金属。了解这些污染物对海洋动物群的潜在影响对于管理全球退役至关重要。本综述由两个方面组成：1) 进行了系统综述，综合了与退役海上结构相关的所有污染物以及 NORM 污染物对海洋生物的影响的文献；2) 对当前用于石油规模和 NORM 成分的退役和表征的环境法规进行严格审查。定义与退役结构相关的化学和放射性污染物的研究非常有限。污染物的主要来源是海上平台，没有来自海底结构。只有三项研究测量了海底石油和天然气基础设施中的水垢材料中镭对生物体的可变化学影响。没有研究测量其他 NORM 对生物体的影响，例如铅 210 和钋 210。目前，没有关于海底管道关闭的国际法规，NORM 被低估并且没有在环境影响评估中得到解决。本综述突出了与退役结构相关的环境监测和 NORM 表征的研究空白。对未来研究的主要建议包括表征 NORM 尺度和通过直接生物暴露实验评估尺度对海洋生物的影响。本综述强调需要将生态毒理学纳入海上石油退役的环境风险评估中。