Chartered Electrical Engineer, Michael Hill, stood as an independent candidate in the 2015 general election on a “Save the Fylde” ticket, highlighting his concerns about the fracking industry. In this guest post, he argues that his message seems more relevant now than ever as he makes the case why the safety limit on fracking-induced earthquakes should not be altered.
Michael Hill
Cuadrilla’s request to relax the rules over earthquakes caused by fracking appears to be based very much on commercial viability and should be refused. The operator must demonstrate that there is a safety reason for doing so or that safety will not be compromised in anyway.
The company has apparently asked for the threshold for seismic activity at which fracking must pause to be raised from a local magnitude (ML) of 0.5 to 2.0.
The industry and government had agreed in 2012 that the 0.5 ML limit was necessary for safety. But following the recent series of earthquakes linked to fracking, Cuadrilla is clearly unable to operate consistently within that limit. The public are very concerned about what has happened and the government has said it will not raise the limit, despite its support for the shale gas industry. So we have a collision of interests between public safety, politics and finances.
Either the limit is raised to allow for the commercial viability of fracking in the UK or safety will take precedence over financial considerations and the science and engineering that led to the introduction of the 0.5 ML limit will be respected.
This might result in fracking being terminated in the UK after just two wells have been fracked and for the same reason: earthquakes.
Cuadrilla’s previous fracking operation in 2011, at Preese Hall, also in the Fylde, was linked to a series of 50 earth tremors.
As the then Technical Advisor to Fylde Borough Council, I reviewed a report commissioned by Cuadrilla on those earthquakes. I also discussed with officials at Cuadrilla and the then Department of Energy and Climate Change the recommended safety limit of 0.5ML. To be clear I did not set the limit but did review the value with the DECC and have first hand knowledge of the debate that took place.
I agreed with senior civil servants that the 0.5ML limit would be very hard to work within. But after long discussions and some mathematical modelling, it was agreed this should be the threshold. The main reason was that considerably larger magnitude earthquakes can and do happen many hours after fracking has stopped. The limit was agreed as it was necessary for safety. This rationale has not changed.
To raise the seismic threshold now has no basis in science or engineering. It will reduce safety and could lead to a catastrophic incident. It must be refused by the UK government regardless of pressure from the industry. Safety must always take precedence over commercial viability.
The industry is endeavouring to focus the media and public’s eyes on “felt” seismicity. It is talking about the level of earthquakes that actually shake our houses.
But the risk at the moment is not to construction above the ground but to what lies below: the wellbore itself.
We do not know the intensity of the ground movement at the borehole but it is immediately clear that the intensity at the wellbore must be greater than at the surface. Just as in April 2011 when the first well to be fracked (Preese Hall 1) was damaged, this must be a very real possibility now. We do not know.
The cement surrounds the steel tubes inside the borehole (casing) and it fills the gap between the casing and the borehole wall – the actual rocks that have been drilled through. It is the only thing that is stopping (to date) up to 11.5 million litres of fracking waste from vertically migrating up the side of the borehole. It can do this in the annulus between the cement and the casing and can move up to the higher areas and eventually the aquifer.
Why would fluid move upwards against gravity? The reason is twofold. Firstly it is understood by hydrogeologists that fracking fluids are less dense than surrounding formation fluids and hence rise; and secondly the pressures during and immediately after fracking are huge (in the range 2,000 – 15,000 psi). The fracking fluid will find the path of least resistance. Due to repeated and increasing energy earthquakes, the gap around the casing and between the cement and the formation wall could have increased.
The integrity of the well – keeping full control of fluids in the well at all times – is critical to protecting us from pollution. Cuadrilla has said it is checking and verifying well integrity after each earthquake by monitoring the annular pressure.
But annular pressure is a very crude tool. It will tell an operator if well integrity is lost – but an entire string of cement must have failed before you will know anything. As you typically only have three strings in an entire well then this represents a very significant failure before you are aware of it. Annular pressure checks on their own are not enough to guarantee well integrity.
There are other measures that should be conducted. Also training on the “habitualisation of risk” must be reinforced. This is where it becomes “normal” to have repeated earthquakes and workers start to ignore what are in fact significant risks to well integrity. They “believe their own press” that all is fine, the AP says so and the procedures are working – so they think. In fact the opposite can be the case but you just don’t realise it as you have alarm fatigue and become habitualised to the risk.
Habitualisation of risk is, I believe, already happening with Cuadrilla’s calls to increase the 0.5ML seismic threshold. The regulators – Environment Agency, Oil & Gas Authority and Health and Safety Executive – may also be experiencing it. They concluded in the latest community bulletin that the seismic activity near the site was within the expected range for fracking. This plays down the very real threat to the well and attempts to normalise a very abnormal situation.
The Environment Agency has said it would demand that fracking is stopped if there was a loss of integrity that could lead to contamination following a quake. But it relies on Cuadrilla’s daily reports to confirm there are no well integrity issues. One may conclude allowing “the regulated” to tell “the regulator” what is the situation on something so important is taking “self-regulation” to dangerous levels.
The regulators have failed to answer my questions: how is it that earthquakes of increasing magnitude and quite astonishing frequency (as per BGS website) above 0.5ML can ever be in line with the agreed Hydraulic Fracturing Plan? To have quakes of 1.1ML – pause for 18 hours, reduce the pressure and then continue – which has nearly always led to a bigger event – how is this “managing seismicity”?
The regulators should take responsibility for what they are responsible for. They must act now – not after the damage has been done. The present scenario being presented by the operator appears to be: we agreed to the 0.5 limit, we helped set it up, we thought we could operate within it, now we discover we can’t, we do not understand why, so let’s raise the limit so we can hit the formations with a bigger hammer and see what happens then!
As a Chartered Engineer, heavily involved in this topic for a long period, I feel it would be reckless to raise the 0.5ML limit. To do so would be putting the public of the Fylde at even greater risk of severe damage to health and the environment than they already are. The 0.5ML limit is there for a reason and that reason has not changed. Safety must always take precedence over commercial viability.
Michael Hill, BSc (Hons) C.Eng. MIET, Expert Member of the Technical Working Group on Hydrocarbons at the EU Commission.
This post is based on a more detailed analysis of the earthquakes caused and the risks of increasing the seismic safety threshold: Independent engineering review of the earthquakes on the Fylde caused by fracking. This analysis has been sent to: Tom Wheeler, Director of Regulation Oil and Gas Authority, Clare Perry MP, energy and clean growth minister; Greg Clark MP, secretary of state for business, energy and industrial strategy; Sir James Bevan, chief executive, Environment Agency.
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I don’t think the minister will agree to Cuadrilla request. It is political suicide.
Mike Hill is an electrical engineer. Its like being given advice on your cardiology by the guy who made the stethoscope.
Cement bond is checked both by sonic and pressure testing There are multiple separate cemented sections up a well which makes simultaneous failure pretty damn unlikely. And fluid is categorically not under fracturing pressure throughout the entire well as Hill implies, it is only the reservoir. It is also under pressure only for the few hours while the fractures are being formed and thereafter, for the life of the well it is at lower pressure than the reservoir (because thats why the gas flows out). If there is a pressure path to surface, the pressure would leak off, fracturing will not work, and someone would be able to see that immediately.
Hill’s lecturing on well integrity is Walter Mitty-like. Just being a chartered engineer buys him kudos only with those who dont know any better.
The EA agree with the 0.5 magnitude threshold.
Taken from the 2012 UK shale gas summit.
The EA’s Tony Grayling said a 0.5 limit was practicable. “The reason why the DECC report set the seismic limit at 0.5 magnitude far lower than the 1.7 is because there is a time delay between the fracking process and larger tremors. Unless you stop them at a lower level you risk a larger tremor later.”
Martin, and your criticism is based on exactly what qualifications and relevant experience please?
Hi Peter, its based on a geology degree and so far, several decades geology experience on exploration, appraisal and development wells offshore UK & Europe.
I’d be surprised if the red light limit was increased and I think it has served its purpose already, but if it is to be re evaluated, it would be done on advice of the geophysicists and rock mechanics people using the data collected so far, and not by electrical engineers.
‘would be done on advice of the geophysicists and rock mechanics people using the data collected so far’
Presumably geophysicists and rock mechanics people other than the ones who advised Cuadrilla at Preese Hall or the ones who advised on Cuadrilla’s ES which states’
“The hydraulic events induced by hydraulic fracturing do not typically exceed magnitude 0 ML and very rarely exceed 0.5 ML.”
Those people clearly have no idea about the subject.
Anybody found any proof that Cuadrilla have actually fracked anywhere in Europe for comparison on seismic activity?
SAVE THE COUNTRY: Stop listening to self proclaimed experts!
SAVE THE COUNTRY……………..with fracking.
As priceless as it is ridiculous.
The comments from Martin are accurate and as someone with extensive experience in the area of well integrity, I can verify his comments. Your need to question the comments displays your lack of understanding on the subject.
The current limit is there as it was chosen without experience of UK conditions. Nothing wrong with that. Obviously correct to start at a level that is very conservative, but as with most engineering, experience will determine whether it is appropriate or optimum. Without that, we would be driving around in Model Ts.
The limits were set in accordance with experience gained duriing Cuadrillas last failed attempts at fracking at PH1.
Really crembrule? If that is your idea of experience, good luck with that.
Good job you were not around hunting for food with a bow and arrow. One miss and you would have decided that hunting/gathering was beyond you and being a vegan was the only option. Shame that inappropriate choppers and digestive system would have curtailed your place within evolution.
As an offer towards something sensible, as sites like PNR will be multi-well operations, why not consider traffic lights that operate as the current one does for the first well, and once that one has been completed and assessment shows all is well, then have a second graduation to be used if considered appropriate on the next one? I suspect that such compromise, or similar, will eventually emerge.
What? So if they had shown that they could control their activities by not triggering any ambers or reds then the regulators might have agreed to let them go a little higher. Yes, that might have worked I guess. Trouble is that over the course of just two weeks they proved again and again that, in spite of promising no seismic events, they couldn’t really control the process. That really just shows how right is was to have the limit where it was in the first place doesn’t it Martin?
Indeed it does show how right it was to have the limit set at 0.5 ML.
This is evidenced by the trailing 0.7 ML seismic event on 2018/11/04 at 16:24:06.2 pm, occurring days after their last frack.
Yes really, it is my idea of experience, thanks for asking Martin.
If you carry out an action and you then create a reaction it would be reasonable to deduce that if you reproduce the same conditions you may produce the same outcomes. Therefore to avoid the same results alter a variable and report on the result.
Now if the same reaction is reproduced either you have not altered the variable enough or possibly altered the wrong variable.
It’s not rocket science.
I suggest people consider the varied engineering skills and roles necessary to extract oil and gas. From what I have just read Electrical Engineers do and can work in a number of O&G disciplines, including wireline, whatever that is.
You are correct in that electrical engineers can work as electric wireline engineers and also in seismic aquisition. Electric wireline is used to run various logging tools in wells to measure porosity / resisitivity / density / lithology / pressure gauges / temperature sondes / even John Powney’s notorious CBLs (cement bond logs). Also used to run wireline conveyed perforating guns, back off explosives and lots of other tools. A few tools contain radioactive sources.
Mr Hill apparently applied to Cuadrilla for a job then turned up working for FOE so perhaps Cuadrilla declined? He designed centrifuge screens to clean up frack flowback waste but perhaps no one wanted them? Stood as anti fracking candidate in the 2015 GE – did better than the Greens (Bob Dennett) & LDs put together but hammered by the Conservatives who won. Also did a lot better than Nanny Rothery the Green Party anti fracker in the the 2017 GE (12.5% vs 3%)
And KatT – his report will go straight into file “13”….
Exactly refracktion. Just what I stated. But it does not mean that justifies not adjusting it from there. Your definition of not being in control is simply that a higher reading was recorded. It was below the threshold-by a long way-of being felt at surface or causing any damage.
But your motivation is to grab hold of anything, including dirty tyres, to state the process is not possible. Cuadrilla’s and the Governments, is to give proper testing to determine if it is possible, within reasonable safety parameters.
If you expect such testing not to be adjusted as circumstances and data determines then Gold Standard is no real concern to you, but more fog. The sort of fog that crembrule specialises in, when he conveniently avoids all the anti “input” about the complex geology and faults under the Fylde and suggests that is not a consideration.
I suspect there will be a number of variables being applied during the initial tests and the data will be analysed to see whether the result has been acceptable with the current traffic light limit. Maybe they will decide it is okay to keep at current levels but just drill a heck of a lot more sites to adjust for lower fracturing!!
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Why is noone pointing out that the fracking used on the geothermal well drilled recently in Cornwall, caused and event of 4.0 – still not noticeable and, what do you know?, not reported or cared about by any of the so called protectors?
Sarah, drilling has only just started on the well in Cornwall, it will be some time before they get to the fracking stage.
I do share your concerns that the self named protectors only seem interested in protecting people from earthquakes caused by the oil and gas companies. Protecting people from larger earthquakes caused by other industries doesn’t appear to be on their radar.
I cannot as yet find any traffic light system mentioned for the fracking of the Geothermal well, only a seismic hazard assessment completed by Wardell Armstrong.
The assessment states that seismic events of mag 4 and possibly above or 25,000 times more powerful than the mag 1.1 so far experienced at Preston New Road, can be expected by the residents living and working in the nearby 4000 residential properties and 180 commercial properties.
Not a very level playing field for fracking I the UK.
John Harrison, our concerns are not with the earthquakes themselves but with what damage they can cause to the Fracking wellbore and head, as a cracked pipe could lead to unplanned migration of the toxic and radioactive flowback and hydrocarbons to soil, water and air. The resulting indefinite pollution can be far more damaging than a few cracked walls.
All wells and casings are designed to withstand seismic activity.
Only 0.8% of the 1,725 active oilfield wells in Coalinga suffered damage after being subjected to 5,000 earthquakes, 894 of these events were of mag 2.5 and above, 1 event was a mag 6.8
The towns water, gas and sewage systems collapsed along with a number of buildings, over 90 people were injured.
The energy released by these events were thousands of times greater than the microseismic events that result from hydraulic fracturing.
Logic of some of these comments seems like: I can’t control my car and I keep overshooting the traffic lights: solution move the lights a bit further down the road, perhaps past the junction? Can’t see that causing any problems.