A top-down approach for quantifying methane and speciated VOC emissions from North Sea oil and gas facilities

Author(s):  
Shona Wilde ◽  
Ruth Purvis ◽  
James Lee ◽  
James Hopkins ◽  
Alastair Lewis ◽  
...  

<p>The North Sea is home to around 200 offshore platforms that extract oil and natural gas from beneath the sea. Total offshore emissions (carbon dioxide (CO<sub>2</sub>), nitrogen oxides (NO + NO<sub>2</sub> = NO<sub>x</sub>), nitrous oxide (N<sub>2</sub>O), sulphur dioxide (SO<sub>2</sub>), carbon monoxide (CO), methane (CH<sub>4</sub>) and total VOCs) from upstream oil and gas production in the UK increased by 7 % from 2016 to 2017. Therefore, the accurate measurement and analysis of leakage is critical for global emissions inventories and in terms of mitigating climate change. A recent study (Riddick et al., 2019) showed that on average methane leakage during normal operations is more than double what is reported to the UK National Emissions Inventory (NAEI) for each installation. Here we provide a top-down emissions estimation methodology from which emissions of CH<sub>4</sub> and up to 30 individual volatile organic compounds (VOCs) can be estimated for point-source platforms. We apply a direct integration technique, and use VOC measurements obtained within downwind plumes as a tool for source identification. A total of 16 research flights were conducted as part of a joint project between the UK National Centre for Atmospheric Science (NCAS), BEIS, the UK Offshore Petroleum Regulator for Environment and Decommissioning (OPRED) and Ricardo Energy & Environment to characterise emissions from platforms in the North Sea. The hydrocarbon to ethane enhancement ratio within downwind plumes, measured under well-mixed boundary layer conditions, was used to scale a 1 Hz ethane measurement from the aircraft to other hydrocarbons collected using whole air samplers and measured using GC-FID. This allowed individual VOC emission rates to be calculated and compared to existing inventories. This work highlights how a top down technique can be used to quantify emissions and also provide insight into specific emission sources, in contrast to existing methods which often fail to achieve both simultaneously.</p>

1984 ◽  
Vol 37 (2) ◽  
pp. 251-263
Author(s):  
M. A. F. Pyman ◽  
P. R. Lyon ◽  
G. Rowe May

Since drilling for oil and gas began in the North Sea in the mid 1960s, the possibility of merchant ships colliding with offshore platforms or rigs, has been of concern to both government and operators. There are nearly 100 fixed and floating installations in the UK sector of the North Sea; they vary in size, location and type of construction, but in all cases, collision would pose serious risks to life, pollution and loss of production. Some platforms are near busy shipping lanes and some have several hundred personnel on them at certain times.


2020 ◽  
Author(s):  
Florian Mauffrey ◽  
Tristan Cordier ◽  
Laure Apothéloz‐Perret‐Gentil ◽  
Kristina Cermakova ◽  
Thomas Merzi ◽  
...  

2019 ◽  
Vol 19 (15) ◽  
pp. 9787-9796 ◽  
Author(s):  
Stuart N. Riddick ◽  
Denise L. Mauzerall ◽  
Michael Celia ◽  
Neil R. P. Harris ◽  
Grant Allen ◽  
...  

Abstract. Since 1850 the concentration of atmospheric methane (CH4), a potent greenhouse gas, has more than doubled. Recent studies suggest that emission inventories may be missing sources and underestimating emissions. To investigate whether offshore oil and gas platforms leak CH4 during normal operation, we measured CH4 mole fractions around eight oil and gas production platforms in the North Sea which were neither flaring gas nor offloading oil. We use the measurements from summer 2017, along with meteorological data, in a Gaussian plume model to estimate CH4 emissions from each platform. We find CH4 mole fractions of between 11 and 370 ppb above background concentrations downwind of the platforms measured, corresponding to a median CH4 emission of 6.8 g CH4 s−1 for each platform, with a range of 2.9 to 22.3 g CH4 s−1. When matched to production records, during our measurements individual platforms lost between 0.04 % and 1.4 % of gas produced with a median loss of 0.23 %. When the measured platforms are considered collectively (i.e. the sum of platforms' emission fluxes weighted by the sum of the platforms' production), we estimate the CH4 loss to be 0.19 % of gas production. These estimates are substantially higher than the emissions most recently reported to the National Atmospheric Emission Inventory (NAEI) for total CH4 loss from United Kingdom platforms in the North Sea. The NAEI reports CH4 losses from the offshore oil and gas platforms we measured to be 0.13 % of gas production, with most of their emissions coming from gas flaring and offshore oil loading, neither of which was taking place at the time of our measurements. All oil and gas platforms we observed were found to leak CH4 during normal operation, and much of this leakage has not been included in UK emission inventories. Further research is required to accurately determine total CH4 leakage from all offshore oil and gas operations and to properly include the leakage in national and international emission inventories.


1991 ◽  
Vol 14 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Stewart Brown

The petroliferous sedimentary basins of the UK Continental Shelf are remarkable for the diversity of their reservoir strata. Reservoir rocks in fields currently in production range in age from Devonian to earliest Eocene, but significant hydrocarbon discoveries have also been made in rocks as as young as the mid-Eocene. The reservoirs are predominantly siliciclastic rocks, with facies ranging from continental fluvial and aeolian, to marine gravity flow deposits from sub-wave base environments.In this paper stratigraphic context of the producing horizons in the UK Continental Shelf (UKCS), principally the North Sea, is reviewed, and the sedimentation of the reservoir strata placed in an outline geological history. The main producing horizons are described in summary. Matters of stratigraphic terminology and correlation both between fields and between basins are discussed.A lithostratigraphy for the UK southern North Sea was established by Rhys (1974), and for the central and northern North Sea by Deegan & Scull (1977). Although these schemes have proved to be fairly robust, in the last 13 years the acquisition of new data plus a proliferation of new terms not fully documented in the public domain, argue strongly for a comprehensive revision and rationalization which is beyond the scope of this paper. Attempts in the public domain to standardize nomenclature across international boundaries in the North Sea, pursued by Deegan & Scull (1977) for the UK and Norwegian sectors, have lapsed for the most part in subsequent years.Economic basement in the UK North Sea can be regarded at present


1992 ◽  
pp. 13-21 ◽  
Author(s):  
R. P. W. M. Jacobs ◽  
R. O. H. Grant ◽  
J. Kwant ◽  
J. M. Marquenie ◽  
E. Mentzer

2020 ◽  
Vol 52 (1) ◽  
pp. 488-497 ◽  
Author(s):  
J. G. Gluyas ◽  
P. Arkley

AbstractThe abandoned Innes Field was within Block 30/24 on the western margin of the Central Trough in the UK sector of the North Sea. Hamilton Brothers Oil Company operated the licence, and Innes was the third commercially viable oil discovery in the block after Argyll and Duncan. It was discovered in 1983 with well 30/24-24. Three appraisal wells were drilled, one of which was successful. Oil occurs in the Early Permian Rotliegend Group sandstones sealed by Zechstein Group dolomites and Upper Jurassic shale.The discovery well and successful appraisal well were used for production. Export of light, gas-rich crude was via a 15 km pipeline to Argyll. Innes was produced using pressure decline. It was abandoned in 1992 having produced 5.8 MMbbl of oil and possibly 9.8 bcf of gas. Water cut was a few percent.Innes was re-examined between 2001 and 2003 by the Tuscan Energy/Acorn Oil and Gas partnership with a view to tying the field back to the newly redeveloped Argyll (Ardmore) Field but marginal economics and financial constraints for the two start-up companies prevented any further activity. Enquest currently owns the licence and the company has redeveloped Argyll/Ardmore, as Alma. There are no plans to redevelop Innes.


2020 ◽  
Author(s):  
Shona E. Wilde ◽  
Pamela A. Dominutti ◽  
Stephen J. Andrews ◽  
Stephane J.-B. Bauguitte ◽  
Ralph R. Burton ◽  
...  

Abstract. The North Sea is Europe's key oil and gas (O&G) basin with the output currently meeting 3–4 % of global oil supply. Despite this, there are few observational constraints on the nature of atmospheric emissions from this region, with most information derived from bottom-up inventory estimates. This study reports on airborne measurements of volatile organic compounds (VOCs) emitted from O&G producing regions in the North Sea. VOC source emission signatures for the primary extraction products from offshore fields (oil, gas, condensate, mixed) were determined in four geographic regions. Measured iso-pentane to n-pentane (iC5 / nC5) ratios were 0.89–1.24 for all regions, used as a confirmatory indicator of O&G activities. Light alkanes (ethane, propane, butane, pentane) were the dominant species emitted in all four regions, however total OH reactivity was dominated by unsaturated species, such as 1,3-butadiene, despite their relatively low abundance. Benzene to toluene ratios indicated the influence of possible terrestrial combustion sources of emissions in the southern, gas-producing region of the North Sea, seen only during south or south-westerly wind episodes. However, all other regions showed a characteristic signature of O&G operations. Correlations between ethane (C2H6) and methane (CH4), confirmed O&G production to be the primary CH4 source. The enhancement ratio (ΔC2H6 / ΔCH4) ranged between 0.03–0.18, indicating a spatial dependence on emissions with both wet and dry CH4 emission sources. The excess mole fraction demonstrated that deepwater oil extraction resulted in a greater proportion of emissions of higher carbon number alkanes relative to CH4, whereas gas extraction, typically from shallow waters, resulted in a less complex mix of emissions dominated by CH4. The VOC source profiles measured were similar to those in the UK National Atmospheric Emissions Inventory (NAEI) for oil production, with consistency between the molar ratios of light alkanes to propane. The largest discrepancies between observations and the inventory were for mono-aromatic compounds, highlighting that these species are not currently fully captured in the inventory. These results demonstrate the applicability of VOC measurements to distinguish unique sources within the O&G sector and give an overview of VOC speciation over the North Sea.


2021 ◽  
Author(s):  
Molly lliffe

Abstract The UK was the first major industrialised nation to commit to a Net Zero target by 2050, and Scotland has an even more ambitious target to reach Net Zero by 2045. To realise these targets, hydrogen will play a leading role in the decarbonisation of multiple sectors including industry, transport, heat and power. Offshore wind can be a core component of our future energy infrastructure, and the scale of its potential role in hydrogen production has recently drawn wider attention from policy makers, developers and potential users across a range of sectors. Hydrogen as a route to market for offshore wind therefore presents a transformative opportunity for the North Sea oil and gas sector and the associated UK supply chain. Existing skills and infrastructure in this region can be leveraged to achieve a leading position in this emerging clean fuel source. This opportunity is particularly relevant for sites in the North Sea which are further from shore with good wind resource, where power transmission costs and/or losses would be prohibitive. Additionally, hydrogen offers an interesting route to market for projects unable to obtain firm grid connection, for sites in regions with high grid charges, or where sufficient government revenue support for conventional power generation is not available for all good quality sites.


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