Development of a strategic framework for the comparative assessment of pipeline decommissioning options: optimising environment and fishing interests

作为英国大陆架（UKCS）油气（O&G）开发的一部分，自20世纪60年代以来，已经安装了超过27,000公里的管道。迄今为止，只有2%的反应堆退役，而且很少有关于退役对其他行业和环境的影响的研究。在接下来的6-8年里，大约5600公里的管道将需要在英国大陆架上退役。管道的退役是在个案的基础上考虑的，通过对可用的退役方案进行比较评估。作为比较评估的一部分，运营商必须向监管机构（商业、能源和工业战略部- BEIS）证明，任何拟议的战略都符合确保捕鱼安全和保护海洋环境的国际义务。为此，需要一个全面的证据基础和战略框架，以评估管道关闭对渔业和环境利益的影响。商业捕鱼业是英国大陆架（UKCS）的最大用户之一，众所周知，在管道基础设施和捕鱼区之间存在大量的空间重叠。根据管道类型、海床类型、捕捞强度和渔具类型，海底存在未卸石的退役管道，对渔民存在潜在的钩钩风险。UKCS还包含许多国际上重要的保护特征（栖息地和物种），例如欧盟栖息地指令中列出的（例如冷水珊瑚）和指定海洋保护区内的物种。这些保育特征/物种（CF/S）由于物理影响、沉积物干扰和硬基质的移除而对管道关闭可能很敏感，硬基质为CF/S提供了额外的栖息地和/或保护它们免受拖网捕捞的破坏。本项目将量化所有管道退役方案对渔业和环境的风险/效益，并整合这些风险，以找到每条管道的最佳退役解决方案（从渔民/环境的角度）。这将通过以下方式实现：结合和整理从分析管道录像片段中获得的物种-管道关联的知识（该行业定期收集以监测完整性），关于捕鱼模式和钩断事件的空间数据以及关于CF/S.2的分布和敏感性的数据。开发可灵活组合的空间“风险层”，以评估和最小化所有英国大陆桥管道中所有可行的退役方案对保护利益和渔民的相对风险。将结果评估嵌入退役协议。影响和受益者该项目的主要受益者将是英国政府、他们的顾问、渔民和石油和天然气行业，他们将从所有部门共享的增强的证据基础中受益。该项目的产出将促进与管道退役有关的成本效益，快速，一致和透明的决策。参考文献[1]英国石油天然气公司（2013年）、[2]英国石油天然气公司（2014年）、[3]能源和气候变化部（2011年）、《石油法案》下海上油气设施和管道的退役》[4]PipeFish——针对英国大陆架规模的商业捕鱼优化油气管道的退役。苏格兰海洋和法定自然保护机构，如苏格兰自然遗产和自然英格兰

BackgroundAs part of the exploitation of UK Continental Shelf (UKCS) oil and gas (O&G), more than 27,000 km of pipelines have been installed since the 1960s. To date, only 2% have been decommissioned and there has been little research on the consequences of decommissioning to other industries and the environment [1]. Over the next 6-8 years, approximately 5,600 km of pipelines will require decommissioning on the UKCS [2]. Pipeline decommissioning is considered on a case-by-case basis, by the comparative assessment of the available decommissioning options [3]. As part of the comparative assessment, operators must demonstrate to the regulator (the Department for Business, Energy and Industrial Strategy - BEIS) that any proposed strategy meets international obligations to ensure the safety of fishing and protection of the marine environment. In order to do so, a comprehensive evidence-base and a strategic framework for assessing pipeline decommissioning with respect to fishing and environmental interests is required.The commercial fishing industry is one of largest users of the UK continental shelf (UKCS), and it is known that there is substantial spatial overlap between pipeline infrastructure and fishing [4]. The presence of decommissioned pipelines on the seabed, without rock dump, presents a potential snagging risk to fishers, according to the type of pipeline, seabed type, fishing intensity and gear-type. The UKCS also contains a number of internationally important conservation features (habitats and species), such as those listed in the EU Habitats Directive (e.g. cold-water corals) and those that are included within designated marine protected areas. These conservation features/species (CF/S) are potentially sensitive to pipeline decommissioning as a result of physical impacts, sediment disturbances and the removal of hard substratum which provides additional habitat for the CF/S and/or protection from trawling damage. ObjectiveThis project will result in the quantification of the risks/benefits of all pipeline decommissioning options to both fishing and the environment and the integration of these risks to find the optimal decommissioning solution for each pipe (from the fisher/environmental perspective). This will be achieved by:1. Combining and collating knowledge of species-pipeline associations gained from analysis of video footage of pipelines (collected routinely by the industry for integrity monitoring), spatial data on fishing patterns and snagging incidents, and data on the distribution and sensitivities of CF/S.2. Developing spatial 'risk-layers' that can be flexibly combined to evaluate and minimise the relative risks to conservation interests and fishers, across all UKCS pipelines, from all feasible decommissioning options.3. Embedding the resulting assessment into decommissioning protocols.Impacts and beneficiariesThe main beneficiaries of the project will be the UK Government, their advisors [5], fishers and the oil and gas industry who will benefit from an enhanced evidence-base that is shared across all sectors. The outputs of the project will facilitate cost-effective, rapid, consistent and transparent decision-making in relation to pipeline decommissioning.REFERENCES[1] Oil and Gas UK (2013), Decommissioning of pipelines in the North Sea region[2] Oil and Gas UK (2014), Decommissioning Insight 2014[3] Department for Energy and Climate Change (2011), Decommissioning of Offshore Oil and Gas Installations and Pipelines under the Petroleum Act[4] PipeFish - Optimising the decommissioning of oil and gas pipelines with respect to commercial fishing at the scale of the UK continental shelf. NE/N019369/1[5] Marine Scotland and statutory nature conservation bodies such as Scottish Natural Heritage and Natural England