How much methane do oil and gas wells leak

Methane leakage matters – it is a relatively short lived but powerful greenhouse gas. Until recently, methane leakage has been hardly monitored and it is still not regulated. However, new techniques for monitoring are making it harder for energy companies to brush their emissions under the carpet.

 

Satellite data is increasingly used for tracking emissions

At current rates of global emissions (as far as we know), methane has a similar global heating impact to CO2, in the first few decades after release. [1]. The main sources from human activity are agriculture (especially cattle) and extraction of fossil fuels. There is also some methane released from landfill sites. However, it is really hard to be sure about these impacts, because emissions are not consistently measured. Recently we have developed techniques to measure methane in the atmosphere and track down where it is coming from. We have learned how to use satellite data for this and a new satellite is to be launched next year dedicated to this task [2]. In the interim we mainly use observations from boats or planes over small areas and coverage is sparse. 

Leakage from oil and gas wells vary by at least an order of magnitude

In this post I focus on emissions from oil and gas extraction. As yet there is no regulation on this, even in the EU. Emissions vary by at least an order of magnitude from one region to another and even one well to another. A considerable proportion of leakage is accidental which means it varies over time as well. The highest emissions are from fracked wells. 

Reported figures varying from 0.04% to 7.5%

In a previous post I referred to an article on producing blue hydrogen which used the figure of 3.5% methane leakage from upstream gas supplies. Upstream includes the well, and all the processing and transportation that gets the gas to an industrial site for use. Their figure has been heavily criticised as being too high. Here are some other examples of published emissions.

• 0.04% to 1.4% from North Sea gas platforms based on measurements from boats, varying between sites[3] 
• 0.23% in 2019, average reported by members of the Oil and Gas Climate Initiative [4] 
• 1.3% from US oil and gas wells, measured by aircraft [5] 
• 2.5% globally, calculated from emissions reported by the IEA: 70Mt/year [6]  and global production: 4000 bcm [7] = 2720 Mt/year  (This included downstream emissions too). 
• 3.6% to 7.9% for natural gas from shale formations, mainly from fracking [8] 

National inventories consistently underestimate emissions.

Official inventories generally underestimate emissions. In the US study [5], they concluded the inventory was 60% low. More than half of leakage is from unintentional vents and leaks, often from tanks and equipment. Two thirds comes from the well itself and the first stage of processing which is separating gas and oil. Substantial amounts of leakage are intermittent and accidental. In 2016, a leak in Southern California spewed out methane for 3 months before it was capped [9]. 

The UK inventory reports negligible upstream emissions.

In the UK, the national inventory estimates methane emissions from gas production and supply corresponding to 0.2% of UK production. However, almost all of this is from leakage in gas supply.  Upstream emissions are supposedly negligible - in contrast to the observations mentioned above. The inventory records upstream gas source at just 0.06% of natural gas production. (emissions from [10] and production/imports from [11]).  The distribution system leaks are also variable from region to region. Our local gas network, Cadent, reports 0.4% leakage [12].

Cameras and satellites are picking up leaks across the globe including Europe.

Fortunately it is getting harder to hide unintentional leaks under the carpet. GHGSat Inc reported methane leaks from 8 wells in Turkmenistan in February this year [13]. Also campaigners have funded the Clean Air Task Force to look for leaks with special infra red cameras from oil and gas operations across Europe So far they have identified 120 examples from seven countries: Germany, Hungary, Italy, Romania, Poland, Czech Republic and Austria [14]. 

The International Methane Emissions Observatory is going to collect data.

It is possible to reduce emissions with existing technology but there is no requirement to do so. Arguably this would have been hard to enforce given the difficulty of monitoring but that is changing. As of March this year UNEP announced the creation of an International Methane Emissions Observatory (IMEO), in collaboration with the European Commission. This will collect data from multiple sources, including measurements from scientific studies some commissioned by IMEO [15]. Once we have the data, regulation becomes possible - but how long will this take?.

Some oil and gas companies support monitoring programmes

Some oil and gas companies are supporting monitoring programmes. Chevron, Shell and TotalEnergies have declared their participation in a 12 month research project using GHGSat [16]. Once the system has been demonstrated, it will observe six offshore facilities from each partner. 

Does increasing local (cleaner) production mean less extraction elsewhere?

The evidence we have now is so sparse and inconsistent that it is impossible to formulate policy sensibly. This is changing, but we still have a problem. From the data we have it seems that UK oil and gas production - and in the North Sea generally - is at least better than average.  However, domestic usage is not necessarily from domestic production. North Sea yields are dropping. The industry is pushing hard for development of more fields, saying this will reduce reliance on imports [17]. Oil tycoon Sir Ian Wood says new fields are necessary to stop oil and gas being imported from countries with less strict regulations [18]. However, if we increase extraction here does that actually mean less extraction elsewhere? Or does it simply reduce global prices and help delay demand reduction? 

Meanwhile, it looks like the Cambo oil field near Shetland will be approved [19]. Apparently this is not a new license so it does not need to be tested against our climate change targets. There are pending applications for developing smaller fields including onshore wells in Lincolnshire, Cheshire, Yorkshire, even the Isle of Wight [20].

Governments cannot act without evidence and its lack feels like another delaying tactic.

The industry is taking a risk in expanding production. After all, demand could decrease, subsidies could be withdrawn and carbon taxes could be applied. The first of these is up to us, the others depend on government policy. However, governments cannot act without evidence and this is sadly lacking. It feels to me like another example of delaying tactics from the industry. Thank goodness for campaigning organisation like Clean Air Task Force that are pushing the issue along by collecting the evidence for us.

[1] Methane: a climate blind spot? (Cicero) March 2019 

[2] Burps in space: new satellite to track global methane emissions (Guardian) April 2021 

[3] Methane emissions from oil and gas platforms in the North Sea (Stuart N. Riddick1, Denise L. Mauzerall, Michael Celia, Neil R. P. Harris, Grant Allen, Joseph Pitt, John Staunton-Sykes, Grant L. Forster, Mary Kang. David Lowry, Euan G. Nisbet, and Alistair J. Manning; Atmospheric Chemistry and Physics) August 2019 

[4] Delivering on a low carbon future progress report (Oil and Gas Climate initiative) Dec 2020 

[5] Closing the methane gap in US oil and natural gas production emissions inventories (Jeffrey S. Rutherford, Evan D. Sherwin, Arvind P. Ravikumar, Garvin A. Heath, Jacob Englander, Daniel Cooley, David Lyon, Mark Omara, Quinn Langfitt & Adam R. Brandt; Nature communications) (August 2021 

[6] Overview of Greenhouse Gases (USEPA) 2020 

[7] Natural gas production (Global Energy Statistical Yearbook) 

 

[8] Methane and the greenhouse-gas footprint of natural gas from shale formations(Robert W. Howarth, Renee Santoro & Anthony Ingraffea, Climate Change) April 2011 

[9] Southern California methane leak was largest in U.S. history (Elizabeth Wildon, C&EN) Feb 2016 

[10] National Atmospheric Emissions Inventory (BEIS) 

[11] Digest UK Energy Statistics 2021 chapters 1-7 (BEIS)

[12] Getting Off Gas (Anne Miller, Carbon Neutral Cambridge) Sep 20201

[13] New Climate Satellite Spotted Giant Methane Leak as It Happened (Bloomberg Green) Feb 2021 

 

[14] Infrared images show under-regulated ‘methane crisis’ across Europe (Climate Change News) June 2021 

[15] International Methane Emissions Observatory: a new step in limiting global GHG emissions (Florence School of Regulation) March 2021 

[16] GHGSat Announces Research Project to Demonstrate Satellite-Based Measurement of Methane Emissions from Offshore Sources (GHGSat) July 2021 

[17] North Sea oil producers push UK to back 18 new projects (Financial Times) Sep 2021

[18] Oil tycoon Sir Ian Wood says halting new fields would be 'crazy' (BBC) Aug 2021

[19] Is a new oil field climate change hypocrisy? (BBC) Aug 2021

[20] Applications in the Planning System (drill or drop) Aug 2021