Greenhouse gas emissions from marine decommissioned hydrocarbon wells: leakage detection, monitoring and mitigation strategies

Böttner, Christoph; Haeckel, Matthias; Schmidt, Mark; Berndt, Christian; Vielstädte, Lisa; Kutsch, Jakob A.; Karstens, Jens; Weiß, Tim

doi:10.1016/j.ijggc.2020.103119

Cited by 46 publications

(21 citation statements)

References 71 publications

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“…Vielstädte et al (2017) discuss that one-third of all wells may potentially leak and bring the awareness of a probably unrecognized methane emission pathway contributing to the greenhouse gas inventory. Supporting this estimate, Böttner et al (2020) could show that 28 out of 43 investigated wells in the United Kingdom sector of the North Sea release gas from the seafloor into the water column. Although our data including abandoned wells in the German EEZ do not replicate these FIGURE 10 | Map compiling data acquired at salt diapir Berta, where most of the flare findings were concentrated.…”

Section: Potential Gas Release Related To Abandoned Wellsmentioning

confidence: 81%

“…By extrapolating their observations to the roughly 11,000 abandoned well sites in the North Sea, Vielstädte et al (2017) estimated that 3-17 kt year −1 methane potentially escape from the seafloor, which highly exceeds naturally released methane in this area. A recent study by Böttner et al (2020) suggests that gas release from 1792 investigated decommissioned hydrocarbon wells in the United Kingdom sector of the North Sea is with 0.9-3.7 kt year −1 a major source of methane in the North Sea. Even larger amounts of methane are emitted through well site 22/4b that experienced a man-made blowout in 1990 (Leifer and Judd, 2015 and references therein;Rehder et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

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Seafloor Methane Seepage Related to Salt Diapirism in the Northwestern Part of the German North Sea

et al. 2021

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This study focuses on seafloor methane seep sites and their distribution in the northwestern part of the German North Sea. Methane seepage is a common phenomenon along marine shelves and known to occur in the North Sea, but proof of their existence was lacking in the study area. Using a ship-based multibeam echosounder we detected a minimum of 166 flares that are indicative for free gas releases from the seafloor in the German “Entenschnabel” area, which are not related to morphologic expressions at the seafloor. However, a group of small depressions was detected lacking water column anomalies but with indications of dissolved fluid release. Spatial analysis revealed that flares were not randomly distributed but show a relation to locations of subsurface salt diapirs. More than 60% of all flares were found in the vicinity of the salt diapir “Berta”. Dissolved methane concentrations of ∼100 nM in bottom waters were ten times the background value in the “Entenschnabel” area (CH4 < 10 nM), supporting the finding of enhanced seepage activity in this part of our study area. Furthermore, locations of flares were often related to acoustic blanking and high amplitude reflections in sediment profiler echograms, most prominently observed at location Berta. These hydroacoustic signatures are interpreted to result from increased free gas concentrations in the sediments. Electromagnetic seabed mapping depicts local sediment conductivity anomalies below a flare cluster at Berta, which can be explained by small amounts of free gas in the sediment. In our area of interest, ten abandoned well sites were included in our mapping campaign, but flare observations were spatially not related to these wells. Naturally seeping methane is presumably transported to the seafloor along sub-vertical faults, which have formed concurrently to the updoming salt. Due to the shallow water depths of 30 to 50 m in the study area, flares were observed to reach close to the sea surface and a slight oversaturation of surface waters with methane in the flare-rich northeastern part of the working area indicates that part of the released methane through seepage may contribute to the atmospheric inventory.

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Section: Potential Gas Release Related To Abandoned Wellsmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Seafloor Methane Seepage Related to Salt Diapirism in the Northwestern Part of the German North Sea

et al. 2021

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“…This is because the effect of legacy wells on leakage is debated, with the effects likely to depend on the age, type of cementation, type of plugging, overpressure and other failure conditions (Ide et al., 2006). In the Central North Sea, 28 of 43 studied decommissioned wells had evidence of leakage of gas into the water column (Böttner et al., 2020). Nevertheless, areas highlighted in this study with the greatest CC have relatively low well density. Gas artefacts.…”

Section: Discussionmentioning

confidence: 99%

A regional CO₂ containment assessment of the northern Utsira Formation seal and overburden, northern North Sea

et al. 2021

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Upscaling Carbon Capture and Storage requires identification of suitable storage sites, with robust reservoir seals. The Utsira Formation in the northern North Sea has been flagged as a target for further storage. However, there are no regional studies of seal variability addressing heterogeneities that could facilitate seal bypass. This study aims to: (a) identify, assess and map the elements that promote or restrict fluid migration, (b) develop a matrix to regionally map containment confidence (CC) and (c) rank the different areas for CO 2 containment across the Utsira Formation. The seal and overburden were mapped using a high-resolution, pre-stack depth-migrated Highlights• There is not a laterally-extensive and homogenous seal above the Utsira Formation.• Regional high-resolution data and modern interpretation approaches illuminate potential seal bypass systems.• A novel containment confidence matrix is used to rank the potential CO 2 storage areas.• The workflow for detailed seal and overburden assessment is highly applicable to other basins. | 1987 EAGE LLOYD et aL. F I G U R E 1 Study area with wells and data extent. (a) Context of the study area in the North Sea and the location of the Sleipner injection site. Satellite imagery from the World Imagery layer of ArcMap online. Bathymetry from EMODnet Bathymetry Consortium (2018). (b) A simplified map showing the main structural elements in the study area (modified from Faerseth et al., 1996). (c) Utsira Fm. thickness map (Eidvin et al., 2013) with seismic dataset extent (yellow box). Dots show wells used in this study, and data from those highlighted in white are presented in this study.Oil and gas fields in the region are also indicated. (d) Regional west-east profile of the Jurassic Rift and overlying stratigraphy split into groups to show main structural elements for reference. Inset shows the studied interval.

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“…Furthermore, extensive methane gas leaks have been reported in the North Sea from abandoned wells, [85,86].…”

Section: Natural Gas Perspectivesmentioning

confidence: 99%

Post COVID-19 Recovery and 2050 Climate Change Targets: Changing the Emphasis from Promotion of Renewables to Mandated Curtailment of Fossil Fuels in the EU Policies

Maniatis¹,

Chiaramonti

Heuvel³

2021

Energies

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The present work considers the dramatic changes the COVID-19 pandemic has brought to the global economy, with particular emphasis on energy. Focusing on the European Union, the article discusses the opportunities policy makers can implement to reduce the climate impacts and achieve the Paris Agreement 2050 targets. The analysis specifically looks at the fossil fuels industry and the future of the fossil sector post COVID-19 pandemic. The analysis first revises the fossil fuel sector, and then considers the need for a shift of the global climate change policy from promoting the deployment of renewable energy sources to curtailing the use of fossil fuels. This will be a change to the current global approach, from a relative passive one to a strategically dynamic and proactive one. Such a curtailment should be based on actual volumes of fossil fuels used and not on percentages. Finally, conclusions are preliminary applied to the European Union policies for net zero by 2050 based on a two-fold strategy: continuing and reinforcing the implementation of the Renewable Energy Directive to 2035, while adopting a new directive for fixed and over time increasing curtailment of fossils as of 2025 until 2050.

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Greenhouse gas emissions from marine decommissioned hydrocarbon wells: leakage detection, monitoring and mitigation strategies

Cited by 46 publications

References 71 publications

Seafloor Methane Seepage Related to Salt Diapirism in the Northwestern Part of the German North Sea

Seafloor Methane Seepage Related to Salt Diapirism in the Northwestern Part of the German North Sea

A regional CO₂ containment assessment of the northern Utsira Formation seal and overburden, northern North Sea

Post COVID-19 Recovery and 2050 Climate Change Targets: Changing the Emphasis from Promotion of Renewables to Mandated Curtailment of Fossil Fuels in the EU Policies

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Greenhouse gas emissions from marine decommissioned hydrocarbon wells: leakage detection, monitoring and mitigation strategies

Cited by 46 publications

References 71 publications

Seafloor Methane Seepage Related to Salt Diapirism in the Northwestern Part of the German North Sea

Seafloor Methane Seepage Related to Salt Diapirism in the Northwestern Part of the German North Sea

A regional CO2 containment assessment of the northern Utsira Formation seal and overburden, northern North Sea

Post COVID-19 Recovery and 2050 Climate Change Targets: Changing the Emphasis from Promotion of Renewables to Mandated Curtailment of Fossil Fuels in the EU Policies

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Product

Resources

About

A regional CO₂ containment assessment of the northern Utsira Formation seal and overburden, northern North Sea