New paper: Estimates of error in micro-earthquake magnitude estimation

With excellent timing, on the same day as the new BGS report into the shale oil potential of the Weald Basin, a new paper, written by two co-workers at Bristol Uni and myself, has been released in Geophysical Prospecting. In it, we examine the uncertainties in estimates of event magnitude made on small earthquakes.

This paper is significant for shale gas extraction in the wake of DECC's traffic light system (TLS) proposal for fracking operations. Under the TLS, operational decisions during the fracking process must be taken on events as small as magnitude 0.0 (the amber level), with complete cessation of activities for events larger than magnitude 0.5.

As most people are aware, a magnitude 0 event is very small, at the limit of what can be detected using conventional seismographs (see our efforts at Balcombe, for example). Expensive downhole microseismic monitoring systems are required to robustly detect smaller magnitudes.

The TLS pre-supposes that earthquake magnitudes at this low level can be accurately determined. The purpose of the TLS was to provide a simple-to-understand system to re-assure the public. Uncertainties in event magnitude estimation could undermine this, generating more controversy, not less.

We show in our paper that event magnitude estimations at these low levels can be very uncertain: you can get different answers depending on what methods you use and assumptions you make. It doesn't take too much imagination to think of a scenario where one group reporting on a fracking operation concludes that an induced earthquake was just below the TLS threshold, but another group using a different method finds that the earthquake did exceed it. The current debate over shale gas extraction is febrile enough as it is, can you imagine the recrimination and the confusion that such an eventuality would generate?

A "hasty dash to frack"?

On the whole I've given up writing critiques of articles discussing fracking in the media written by journalists. There's not enough hours in the day, and more importantly, sensationalism - selling papers - is what journalism is all about. You might as well criticise a dog for barking.

However, it's a different story when it's academics writing for the media. The extra respect that members of the public afford to academics means that there is an added responsibility to be accurate. Which brings me on to this article in the Birmingham Post, written by Professor Alister Scott of Birmingham City University, described as "thoughtful" by a senior BBC environmental correspondent.

The first few paragraphs discuss the general discord in the government's energy policy, and I would agree that our energy policy is currently a mess. However, the problems begin when Prof Scott argues that "they have rejected any new EU Directive that would look specifically at issues from the fracking process not covered by existing legislation such as cumulative impact, underground risk assessments, chemical mixes and methane emissions".

It is true that the EU decided to release a Recommendation rather than a Directive. It is however incorrect to claim that the Recommendation has no impact on the activities of operators in the EU. This recommendation mandates a range of measures, including a wide range of environmental factors that operators must assess before, during and after their activities. Member states must inform the EU Commission of measures that they have put in place to meet the requirements of the recommendation.

These measures will be reviewed in 18 months, and if the commission deems that the terms of the recommendation are not being met then they reserve the power to impose legally binding rules at the European level (paragraphs 16.1-16.4). This is hardly the lack of regulation implied by Prof Scott. I'll note in passing that disclosure of the "chemical mix" is required by the Environment Agency.

In his next sentence, Prof Scott claims that "They have even gone further to say that some environmental safeguards should be reduced due the complex burden of permissions and licenses". I'd love to know what environmental safeguards Prof Scott thinks have been reduced? There are moves to reduce the amount of time taken to get permits, and to improve coordination between the various agencies involved (DECC, Local Minerals Planning, EA, HSE). There has been absolutely no move to reduce the environmental safeguards expected during drilling and hydraulic stimulation.

Prof Scott argues that "We need evidence-based policy and we have seen a debate that is more akin to a pantomime. The debate becomes stuck in a groundhog day mentality becoming sterile and increasingly polarised". I'd love to know what Prof Scott thinks is more inductive to "pantomime" debate: reports by the Royal Society, by Public Health England, by the Institute of Directors? Or this?

The renewables industry has long offered payments to local communities to persuade them to accept wind and/or solar farms in their area. However, when shale gas companies offer something similar, "The rush to provide incentives to people and communities affected by fracking is troublesome in social and environmental justice terms". That said, I do agree with the thought that the expectation that shale operators make community payments when industrial developments with a far greater impact - coal mining, large facilities etc - do not could be seen as unfair.

The next claim is that "continual government attacks on environmental safeguards as restricting development encircle the fracking debate". Again, I'd love to know what these attacks on safeguards are? Yes, there is the intention to streamline to permitting process and to improve coordination between agencies. The has been no suggestion of any reduction in any existing environmental safeguard that applies to drilling and/or to hydraulic fracturing.

The fact that "government ministers are quick to condemn 'unsightly' solar and wind turbine developments, but seemingly embrace landscapes of fracking infrastructure" may well be because of the very different scales of impact the two industries have, when measured on a per MWh basis. A single multi-lateral well pad, which might look something like this when completed, will produce as much energy as the entire Scout Moor wind farm, which looks like this. 

I can sympathise that the level of public engagement has perhaps not been what it might be. I'm not sure how mis-informed articles by academics in the media are supposed to improve this. However, there is already abundant "independent scientific evidence", if one cares to look for it, while every kind of measurement possible is being made around putative drilling sites to ensure "effective safeguards for the public and the environment and effective monitoring arrangements". Cuadrilla's Environmental Impact Report for their two new sites in Lancashire will run to over 3,000 pages. Given Prof Scott's concerns, I am sure he will read every page. 

Prof Scott's conclusion is that we're seeing a "hasty dash to frack". The prospects for shale gas in the UK were first realised in the late 2000s, and Cuadrilla drilled and tracked their well in 2011 - still the only onshore well where fracking has been used in shale rocks (as opposed to fracking in conventional reservoirs, which has been done approximately 200 times onshore in the UK). Since then, we've seen about 5 exploration wells drilled, and the first intention to frack a well submitted by Cuadrilla, where stimulation will probably take place in 2015, once the 3,000 environmental assessment has been completed. 

Meanwhile, in the USA thousands of wells will have been drilled and fracked. Meanwhile, other countries with shale potential are making solid progress, and drilling and fracking multiple wells. Argentina, China and Poland spring to mind. If 5 wells drilled and one fracked in 4 years represents "a hasty dash to frack" to Prof Scott, I'd hate to see what slow progress looks like.  

Some more comments on the BGS Weald report

Now that the dust has settled from the BGS Weald report, the general consensus is that the numbers are a little disappointing, with 4.4bn bbl not comparing particularly favourably with over 100bn bbl in the Bakken Shale, for example, or the 40bn bbl we have extracted from the North Sea.

Perhaps we've all been spoiled by the numbers from the Bowland shale, so that anything less than world class numbers comes as a disappointment. Some outlets seem to have been a little confused by the report's conclusion that there was no prospectivity for shale gas, thinking this to mean no prospectivity for any kind of hydrocarbon-bearing shale.

In terms of value, if we assume a 10% recovery rate, at £80 per bbl, 440 million bbl is still worth 35 billion. Nothing like the £1 trillion of recoverable gas estimated to be in the Bowland shale in the northwest, but not to be completely sniffed at either. I anticipate that we'll still see operators looking to develop the Weald resource, especially if oil looks like staying at £80 per bbl or more. But it's not going to change the UK energy landscape in the way the Bowland shale gas numbers could.

I would't be surprised if certain operators will feel privately that their acreage has more in it than the BGS have estimated. After all, we can never know the true numbers until we drill more wells specifically targeting the shale - in the same way that we'll never know if the huge Bowland shale numbers are accurate until we start drilling.

The other issue is recovery rates. The higher viscosity of oil compared to gas means that recovery rates for shale are not as high as for gas. I have little doubt that operators in the Bakken are already trying to find ways to increase their recovery rates. We've seen something similar in the US shale gas plays, which have been around a little longer, with recovery rates seeming to increase year-on-year. For a smaller resource estimate, maximising recovery rate will be particularly important.

BGS report on Weald Basin expected today

Update 23.5.2014: The report has now been released and is available here. The headline number is a resource of 4.4 billion barrels of oil in place.



The big news today is that the BGS report into the hydrocarbon potential of shale rocks in the Weald Basin will be released.

The Weald Basin stretches across the south of England, through the home counties from Dorset to Kent. It already hosts one very large oilfield at Wytch Farm (the EU's largest onshore oil field) and a number of smaller onshore oil and gas fields. The general public is largely unaware of these fields - I can speak from experience because I grew up almost directly above one of them - Humbly Grove in north Hampshire. I had little idea it was there until I went off to university to study geology.

In case you are wondering, here's a map of existing fields and licences, and below is a map of existing oil and gas wells drilled in the region

A visit to the Heping cement CO2 capture demonstration project in Taiwan

Update (25.5.2014): Since I have arrived home and am no longer relying on dodgy hotel internet, I have been able to upload a video of the plant I took while I was there. The video gives a better idea of the scale of the factory that the picture cannot, simply because you can't fit the whole plant into the shot. The video is on YouTube, but I've embedded it here:

Also, if you want an aerial view of the plant, you can find it on google maps here.

The introduction to this post is that I'm writing it from the luxury of a rather swanky 5-star hotel in Taipei.

Taiwan is not in a great position with respect to energy. They have few natural resources of their own to utilise - only a few small natural gas fields in the north of the country. Nuclear is a troublesome subject for such an earthquake-prone island, especially after Fukushima. While you might think that such a mountainous island would be a good site for renewables, the regular earthquakes, landslides and typhoons means that maintaining a large number of wind turbines will also prove difficult. As a result, the majority of Taiwan's electricity comes from coal, most of which is imported from Indonesia.

Image of the Day: Oil and Gas Wells in the USA

The USA has drilled a lot of oil and gas wells in the last 100 years or so. More than a million in fact! Here's a map showing where they are. It's quite an eye-opener!

Image of the day: Comparing a train to a fracking-induced earthquake

This image compares the vibrations from a passing train, measured at a distance of 150m, to a simulated earthquake occurring 2km below Cuadrilla's Balcombe drilling site (from the Bristol University Balcombe baseline study). We found that the train vibrations had similar amplitude to a magnitude 1.5 earthquake, equivalent to the second quake that lead to the shut down Cuadrilla's operations in Blackpool in 2011 (and a two-year moratorium).

Frack Free Somerset and the ASA

Earlier this year I was contacted by a local Somerset resident. He'd attended a meeting hosted by Frack Free Somerset, and had concerns about the accuracy of the promotional materials they'd used.

The resident was intending to submit a complaint to the ASA regarding these materials, and got in touch with me for some advice about some technical details, which I was happy to provide.

The ASA began their investigation, but the issue has now been resolved as FFS have agreed to withdraw the offending literature without rebuttal (Informally Resolved Cases, Date 7th May 2014). By doing so, there is no requirement for formal investigation.

As far as I see it, this represents tacit acceptance that all of the original complaints are valid. However, by withdrawing rather than making a challenge, FFS have managed to avoid the media fanfare associated with a full ASA investigation.      

There is an obvious comparison here with Cuadrilla's ASA investigation. Of the 18 complaints made by anti-fracking groups, only 6 were upheld by the ASA. In contrast, it would appear that FFS are not even prepared to try and defend the contents of their own promotional materials.

I have re-posted the original FFS brochure here, and the complaint from the local Somerset resident here.




The complaint cites a number of supplementary materials. These are as follows. Attachments 1a-e were data sheets taken at random from Barnett shale wells on the FracFocus website, summarised in attachment 1f. Attachment 2 was DECC's document about fracking and water. Attachment 3 summarised cancer incident rates in Barnett Shale counties (Denton, Johnson, Parker, Tarrant, Wise) taken from http://statecancerprofiles.cancer.gov. Attachment 4 detailed key health indicators for Denton County taken from Mickley and Blake. Attachment 5 was the DECC document on shale gas regulations and safety. Attachment 6 shows US natural gas prices and shale gas extraction rates (easily available just about anywhere), and Attachment 7 compares coal and CCGT power station efficiencies, Figure 6 in this EIA report.

Letters to the Independent

Several letters have been published in the Independent in response to its recent editorial on shale gas extraction in the UK. Because these letters appear to come from academics, with letters and titles before their names, it seems appropriate that I join the discussion.

The first letter is from Professor Andrew Watterson of the University of Stirling. Prof. Watterson argues that

Unconventional gas is not part of an energy solution; it is a major pollutant. It diverts cash, resources and expertise away from work on the more sustainable energy solutions that are now available. 

We are running out of time on global warming if we do not develop sustainable energy sources now and reduce unconventional gas extraction, not increase it.

These comments are in stark contrast to the conclusions reached by the IPCC, who are considered by most to represent the final word on climate-related issues. In their Summary for Policymakers, they state that

GHG emissions from energy supply can be reduced significantly by replacing current world average coal‐fired power plants with modern, highly efficient natural gas combined‐cycle power plants or combined heat and power plants, provided that natural gas is available and the fugitive emissions associated with extraction and supply are low or mitigated. In mitigation scenarios reaching about 450 ppm CO2eq concentrations by 2100, natural gas power generation without CCS acts as a bridge technology, with deployment increasing before peaking and falling to below current levels by 2050 and declining further in the second half of the century.

During the press conference to mark the release of this report, the IPCC spokesman was queried about shale gas. His response was

We have in the energy supply also the shale gas revolution, and we say that this can be very consistent with low carbon development, with decarbonisation. That's quite clear.

Clearly, Prof Watterson and the IPCC are in disagreement. I suggest that he takes this up with them.

Prof Watterson then argues that

It diverts cash, resources and expertise away from work on the more sustainable energy solutions that are now available

The figure below shows installed wind capacity in the USA in green, and shale gas production in blue (both normalised to 2013 values). Perhaps even more wind power would have been constructed without the shale revolution, but I don't really see any evidence here of shale gas development distracting from alternative power sources. Indeed, the leaders of several renewable energy industry groups are on record as saying that cheap gas provided by shale has helped them deal with the inevitable renewable energy intermittence issues.

As for the notion that current events in Ukraine can be dismissed as a "scare stor[y] about ephemeral energy-supply crises in Eastern Europe", well, this is hardly worthy of comment, suffice to say that Eastern Europeans are very keen to access secure gas supplies, for obvious reasons.

Prof Watterson is also unable to "make sense" of the possibility of having regulations that are both strong and yet do not cause undue delay to operators. The purpose of regulations is to ensure that operating practices take every safety precaution into account to ensure that risk is as low as reasonably possible (ALARP). The purpose of regulations is not to cause operators unnecessary delay unless doing so will make an operation safer. At present, to drill and frack a well, shale gas operators need a wealth of permits and permissions from a variety of bodies, including DECC, the Health and Safety Executive, the Environment Agency, and local planning agencies.

These agencies all work in different ways and to different timescales. "Streamlining" regulations across these organisations will not mean that a well is or is not cemented properly; or that cement bond logs are or are not run to detect any well integrity issues; or that multiple bunding layers are or are not installed to isolate the drill pads from groundwater; or that methane is or is not monitored in groundwater and in the air before, during and after drilling; or that fluids are or are not stored in double lined steel tanks, placed on drip trays. No-one is talking about changing any of the regulations pertaining to these issues. Simply that the process of applying for permits is made more efficient not only for the operator, but also for the regulating agencies: it is equally important that the different regulators know what each is doing with respect to a particular application.  

Dr Robin Russell-Jones also takes issue with the IPCC conclusions on shale gas. Development of shale gas may well lock us in to production for at least 30 years, but then the IPCC argues that gas consumption must increase between now and 2050 (36 years hence) to meet 450ppm stabilisation targets.

Dr Russell-Jones also takes issue with the assumption that "transition to a truly green energy system is unachievable". Whether or not this is really true or not, I genuinely do not know. I'd like it to be possible. However, no modern industrialised country, with the exception of a few small, unusual cases (for example Iceland with abundant and easily accessed geothermal) has yet achieved this, or come even remotely close to achieving this. So I do not know where Dr Russell-Jones gets his evidence from to declare it to be so adamantly untrue. His second comment is simply not supported by evidence. While estimates of methane emissions from shale pads have varied, no measurements have shown that methane levels have reached those needed to make natural gas worse for global warming than coal. Moreover, natural gas leaks are easily fixed where necessary.

Finally, Dr Lowry argues that shale extraction in this country may be uneconomic anyway. In which case lots of gas companies will lose money, which surely is no bad thing if you oppose the use of natural gas. Given that the money invested is their own, these companies can sink or swim on the basis of their own decision making. Clearly Dr Lowry knows more than the geologists employed by Total, GDF Suez and Centrica.

Moreover, the reason that some gas companies are struggling in the USA at present is because the price of gas has plummeted there, which has been great news for domestic and industrial consumers alike. If Dr Lowry is arguing that we'll see a similar plummet here then I am sure the news will be welcomed by most. If, as is more likely, gas prices are reduced a certain extent but not to the amount seen in the USA, then shale gas extraction will remain viable, and will be taxed, providing much-needed funds for local and national government alike.