Tremors pause fracking again at Cuadrilla’s Lancashire shale gas site

Preston New Road cu Cuadrilla Resources

Cuadrilla’s Preston New Road site near Blackpool. Photo: Cuadrilla Resources

More earth tremors overnight were strong enough to stop fracking for a second time this month at Cuadrilla’s shale gas site at Preston New Road near Blackpool.

The company said the tremors followed pumping operations yesterday (Friday 23 August 2019).

A statement, issued at 12.30am this morning, said there had been a 1.05ML event at 11.22pm yesterday.

A second statement, issued just after 6am, said a 0.53ML event had been detected at 5.01am.

Both statements said the tremors lasted “less than 1 second” and ground level vibration was about 0.4 mm/s.

Cuadrilla added:

“The integrity of the well has been confirmed.”

A smaller tremor, measuring 0.12ML at 10.41pm last night, was also reported by the company on its website.

At the time of writing, the British Geological Survey had confirmed one of the overnight tremors. It recorded the larger one at 1.1ML. The approximate depth was put at 3km, about 1km deeper than most of the previous seismic events at Preston New Road.

Earth tremors which happen after fracking has finished for the day are described as trailing events. Under Cuadrilla’s hydraulic fracturing plan for the PNR2 well, fracking must pause for 18 hours where the trailing event measures 0.5ML or above.

The company was required to pause fracking on PNR2 for the first time on Wednesday (21 August 2019) after a 1.55ML trailing event. This was the largest tremor so far recorded at Preston New Road. It was felt by people living in Blackpool, Lytham St Annes and villages near the site. A 1.0ML event on Thursday was also felt locally.

On its website, Cuadrilla said:

“Local people should be reassured that any resulting ground motion will be far below anything that could cause harm or damage and is likely to be much less than caused daily by other industries such as quarrying or construction or even heavy goods vehicles travelling on our roads.”

But a neighbour of the Preston New Road site told DrillOrDrop today:

“Given the number and intensity of the trailing events following Wednesday nights 1.55ML event, we are surprised the Cuadrilla and the Oil and Gas Authority thought it prudent to resume fracking so soon.

“With three more trailing events being reported overnight, we now wonder what the number and magnitude of earth tremors we can expect over this Bank Holiday weekend.”

Fracking began on PNR2 on 15 August 2019. Since then, there have been more than 80 seismic events. Three in the past four days have measured more than 1.0ML. So far, there have been red events, where earth tremors during fracking measure more than 0.5ML.

In autumn 2018, fracking of the first well, PNR1z, was paused several times by earth tremors.

During that operation, Cuadrilla called for the 0.5ML threshold to be raised.

89 replies »

  1. “Fracking must pause for 18 hours where the trailing event measures 0.5ML or above.”

    Ruth can you verify this please. The HFP ( shows a flow chart on p23 that contradicts this (showing the 18 hour pause only affecting events while pumping), and was signed off by the OGA according to this site.

    However, I have heard that an OGA representative contradicted the flow chart and supported what you say here.

    The whole situation is terribly unsatisfactory – hardly “gold standard” is it?

    • I have puzzled over this too. It seems to me unless I am missing something that the 18 hours, according to Cuadrilla’s fracking plan, applies to >0.5 during “pumping operations”. Trailing events >0.5 mean well integrity test and reporting but no assumed fracking delay. And if < 15mm/s just carry on fracking.

      As an admitted layman, but having studied the subect over some years, it now seems clear to me that the TLS system and its implementation is fundamentally flawed. What we are now seeing appears to suggest that after-fracking events are more significant than during fracking events, and this is due to fault slipping as was predicted, though not by Cuadrilla, whose knowledge of the geology is still – or even more – in doubt. Have Cuadrilla learned anything? It seems not. The only course of action that appears reasonable in the current situation is for the "authorities" to shut down the operation and conduct a full inquiry.

      Maybe Mr Menzies might agree. Or not.

      • There are NO SUCH THING as trailing events, they are an artificial construct by someone (DECC, BEIS, Industry??) and certainly not by me (Professor Peter Styles who was part of the triad,( I hesitate to use the word triumvirate) who established the TLS). These are events which occur as the fluid hydraulic changes and stress changes propagate away from the immediately fracked region and are, and always have been seen as an integral part of the seismicity response of the subsurface. The earth’s response to the fracking event is not instantaneous and to somehow pretend that they are not a consequence of the fracking process is derisory.

        • Thanks, Peter. In other words, the original description of the TLS as to stop fracking in progress when seismic events occurred was misleading. I totally agree. Having looked at an updated version of Cuadrilla’s fracking plan at PNR 2 (not on their website perhaps) I must say that the 18 hour interpretation is cirrect, not in terms of the TLS but the fracking plan agreed..

          This leads me to ask – if their flowchart should be interpreted as correct, should an 18 hour cessation be imposed BEFORE well integrity tests are carried out to allow the subsurface to respond properly? I am of course not suggesting that well integrity tests should not be performed immediately on red light events being detected, but that before any continuance an appropriate (it is not for me to say whether 18 hours is sufficient, I suspect not in the complicated fault structure of the Fylde) period should elapse?

        • Peter – I totally agree that the term “trailing event” is silly. But does anyone seriously argue that the events after injection are not related to the fracking process? It seems obvious that it’s due to fluid migration or stress transfer. I guess the issue with stress transfer is that it must be via a creep process as it’s far too slow to be caused by the elastic transfer of stress, which would be pretty instantaneous.

          • The faults are a connected network Judith and we may well be consecutively stimulating a sequence of faults to get to the one which produces an event which is big enough to be observed. The real point is that the Hydraulic Fracture plans are being written using terminology which doesn’t stand scrutiny

        • Peter Styles

          See point 15 of the above letter from the OGA, following an FOI request by Richard Parker. dated 3 Jan 2019

          The OGA note that ..

          ‘’KIt is widely recognised that induced seismic events can take place after fracturing ceases, which is called a trailing event’’.

          I have not come across an opinion on here that states trailing events are not associated with the fracking activity.

          • The whole basis of that letter both in the questions and the answers to them is a belief that there are such things as trailing events which can be distinguished in any scientific way from events which occur actually during the fracking. They have invented something which is at best an administrative term.

            If you google “trailing events fracking” the only hits you get are from Cuadrilla and OGA. What I am trying to get across and clearly haven’t made the point strongly enough is that they don’t exist as a concept anywhere else !! (By the way I first monitored fracking (in the UK as it happens) in 1988). They have been ‘made-up’ they are all induced seismic events caused by the fracking process and the subsequent stress readjustments and fluid interaction from the fracking stage.

            Thus anything in the letter and the replies have very little relevance to what is actually going on. If you look at the actual TLS we devised we dealt with seismic events which followed after the actual fracking has been halted.

            • Peter Styles

              Yes, I take your point ( and agree ) that trailing events cannot be distinguished in any scientific way from events that occur during fracking. My point was that I had not seen any indication from those postings on DOD that posters thought that events after fracking were not linked to the frack activity, nor any from the OGA.

              For sure it is an administrative construct, although if they adopted your traffic light system I would not be surprised if the term was replaced by ‘after frac’ and the flow chart amended accordingly ( to keep time flowing from left to right as far as possible ).

    • As I understood it, if a tremor at or above 0.5ML occurs whilst fracking takes place the operator has to stop fracking and pause for 18 hours. If a tremor occurs whist fracking is NOT taking place the operator still has to pause for 18 hours.
      I could be wrong – I could be right.

    • I have found evidence that on at least one occasion, a seismic event greater than 0.5 ML which occurred after pumping did not stop production:

      In October 2018, Reuters reported that @CuadrillaUK “continued production after a ‘trailing event’: “Cuadrilla said one was a so called “trailing event” which didn’t stop production.”

  2. Perhaps the OGA have changed the TLS to include “trailing events” to be treated the same as events which occur during fracture stimulation pumping operations? Hence the 18 hour wait? As noted by Prof Styles above. A secret revision of the TLS to make it tougher and more realistic if “trailing events” are someone’s unqualified invention. Perhaps before the limits area raised?

    • I’ve asked Ruth to post what we actually suggested as the Traffic Light System as opposed to the simpler (CARTOON) version which DECC implemented. There are many more nuances implemented as decision tree branches in the original one which were there for very good reasons. They (DECC or whomsoever) presumably considered that this was too complex but you will note that we dealt with all of the later events post the actual fracture incident (the so-called trailing events) in our version!!!!!

          • Excellent, many thanks Peter. May I ask, given your past concern about fracking near faults, have you had chance to look at our local geology, and/or given Cuadrilla’s experience so far come to any view about the suitabillity of PNR as a fracking site bearing the geology (only) in mind? I appreciate you may not make a public statement, I’ll remind you from our previous correspondence of my email address.

            • Thank you Peter Styles, you are the first person to offer a scientifically explanation of the issue of these “trailing events” that i have been asking for a couple of days now, perhaps mistakenly of the so called qualified “experts” that post here.

              I look forward to the correct explanation being posted on Drill or Drop.

              • Phil C

                I have checked back through your comments to August 15th.

                I can see no question by you asking anyone for an explanation of the issue of trailing events.

                However you did note on August 23rd at 8.12am that ……

                ‘’Still we have not received an explanation of the implications of these ‘trailing events’ from the ‘self claimed superior knowledge’ of those so called experts and no verification to anything in fact.

                Just the usual polarisation of vitriol and false accusations that would be more appropriately aimed at their own behaviour.’’…….

                The above extract from a longer post would indicate that you have already asked the question ( not in the last couple of days ), but have not received a reply.

                However you then indicate that you have had a reply, but in your opinion it was vitriol etc etc .

                It may help if in future you clearly state that you are asking a question, and to whom you are addressing the question to.

                • That is a little creepy hewes? Where did I say I asked that here? I do speak to my colleagues in the profession too you know.

                  You are far too quick to jump to assumptions. But we know that don’t we.

                  Never mind.

                • Phil

                  Phil .. sure could be creepy, we’re you just asking, but not asking a question?

                  In your comment to P Styles above where you say….

                  … are the first person to offer a scientifically explanation of the issue of these trailing events, that I have been asking for a couple of days now, perhaps mistakenly of the so called qualified ‘experts’ that post here.

                  However if your colleagues are the ‘so called qualified’ experts, and they post on here then i wish you good luck in your questioning and look forwards to their answer on here.

                  Regarding my assumption that you say you asked a question, I would just refer to your text above and prior, and happy to leave it at that.

                • Creepier and creepier!

                  Though I can see why you mistakenly assumed that “‘’Still we have not received an explanation of the implications of these ‘trailing events’ from the ‘self claimed superior knowledge’ of those so called experts and no verification to anything in fact.”

                  Might have referred to your good selves on Drill or Drop? An easy mistake to make if you recognise the description too closely, and are too quick to make assumptions.

                  Glad to have cleared up your error though, I’m occassionally here to help if you require any further assistance.

                  Have a nice Sunday.

                • Phil C

                  Thanks for clearing that up. In future I shall assume reference to to your ‘ so called experts’ on DOD as your colleagues, and respect the robust relationship you have with them, and that you take their vitriol and false accusations in good heart.

                  Should you need any information relating to trailing events feel free to ask as there a no doubt a number of people on here, who are not your colleagues but who are happy to answer.

                  Especially as your colleagues in the industry were unable to answer your ask. Maybe they have signed a confidentiality agreement with Cuadrilla.

                • Well good morning ladies and gentlemen, boys and girls, it is the second Sunday since fracking was resurrected by Cuadrilla at Preston New Road for the third time.

                  And already there has been seismic events that exceed the agree TLS limit of 0.5Ml before fracking has to be suspended for 18 hours. There has I understand been a very recent 2.1Ml event this morning and a 1.6Ml event prior to that.

                  These are termed as “trailing events” but the very term is now in hot dispute as it is a spurious term and has no logical meaning whatsoever, and that all events such as we are seeing now are a result of the tracking activities and should not be separated out from the tracking operations regardless of whether fracking operations have ceased for the day.

                  Therefore that spurious term “trailing event” must also be dropped from the conditions and descriptions.

                  It has also been fascinating talking to Professor Peter Styles that the TLS as it stands is a much watered down version of the original teams proposals, of which Professor Peter Styles was a member. That watering down of the TLS was carried out without the original teams agreement or consent, and it is as yet unclear who or what secretive agreement enabled that compromising reduction of the TLS criteria in any case.

                  It is clear that far from watering down the TLS further, which is what Cuadrilla et al have been angling for, that the situation must be quite the reverse and that the limits and conditions of the TLS must be strengthened and restored back to the original intention of the team. Only then will the intentions of the team be reflected in the reality of the TLS agreement.

                  We have also see that Cuadrilla have entered into a secret Non Disclosure Agreement with the British Geological Society to force the BGS to request permission from Cuadrilla for the release of sensitive data and correspondence and actually destroy data if requested by Cuadrilla. That is a travesty of an agreement with a scientific publicly funded organisation and must be challenged or we descend into a censored concealed regime where nothing of the BGS remains of any scientific validity whatsoever.

                  We can only surmise if similar Non Disclosure Agreements have been entered into with the OGA and the EA, and how much of the correspondence and data from all three publicly funded organisations have been withheld or entirely destroyed under such agreements. There is clearly an awful lot to be revealed about these publicly funded, but apparently thoroughly compromised organisations that should have been relied upon to protect and determinate all their scientific data, and not to have it under the strict control and censorship of private corporations. That will be another storm on the horizon that will run and run and run.

                  So there are clearly many elements that are occurring in the activities of Cuadrilla at Preston New Road all at the same time. There are interesting times ahead and some of those storms on the horizon may change the entire fracking scenario in the UK.

                  Have a great Sunday with family and friends and perhaps just begin to consider how all the watering down of the TLS and the secret NDA’s and the recent seismic events term of trailing events have been allowed to happen in secret and how much they have severely compromised the entire public confidence in the government’s and corporate handling of the fossil fuel onshore operations in the UK.

                • This is David Kesteven again on the recent inquiries into the intended Ineos fossil fuel exploration activities at Woodsetts. You may remember the hotly debated intentions of Ineos, to construct an access track to their site besides residential homes and the announcement of a bizarre “sound proof fence” to prevent noise, but that turned out to be an eyesore and an intrusion in itself?

                  Lessons In Fighting Fracking

                  There is advice resulting from the Woodsetts inquiry as to how to go about fighting such a proposal elsewhere, so it is worth a look just for that alone.

                  You may also be aware that James Brokenshire, a name to be conjured with, took over the planning decision of Woodsetts and several others to make his decision early in the new year. You may also know that James Brokenshire is no longer in that position in the new conservative cabinet under Boris Johnson, so that has been left pretty much high in the air for now. No doubt we will see when Parliament returns from the summer break.

                  I thought that the best way to celebrate the Woodsetts inquiry was a song, but which song? And then it occurred to me, of course!

                  So here is “Woodsetts”

                  Based on the famous Joni Mitchell Lyrics for: “Woodstock”

                  I came upon a child of God
                  He was walking along the road
                  And I asked him, where are you going
                  And this he told me…
                  I’m going on down to Woodsetts
                  I’m going to join an anti fossil fuel band
                  I’m going to camp out on the land
                  I’m gonna try and set my soul free

                  We are stardust
                  We are golden
                  And we’ve got to get ourselves
                  Back to the garden

                  Then can I walk beside you
                  I have come here to lose the fog
                  And I feel to be a cog in something turning
                  Well maybe it is just the time of year
                  Or maybe it’s the time of man
                  I don’t know who I am
                  But ‘ya’ll know life is for learning

                  We are stardust
                  We are golden
                  And we’ve got to get ourselves
                  Back to the garden

                  By the time we got to Woodsetts
                  We were half a billion strong
                  And everywhere there was song and celebration
                  And I dreamed I saw the oil ‘n gassers
                  Riding blacksun in the sky
                  And they were turning into butterflies
                  Above our nation

                  We are stardust
                  Billion-year-old carbon
                  We are golden
                  Caught in the devil’s bargain
                  And we’ve got to get ourselves
                  Back to the garden

                  There, wasn’t that wonderful? For all those who remember those halcyon days when we thought that anything is possible with love and humanity and flowers in the sun.

                  But there was always going to be a backlash from those who are filled with greed and avarice, hatred and destruction and utter contempt for the planet and everything, and everyone that lives here.

                  So perhaps just today it is great to remember that we really can make a difference and that is already happening, maybe the future isnt so dark as these fatalistic defeatists and obsessive fixated creeps will try and make it.

                  Have a great Sunday and enjoy this marvellous day and maybe also think of our children and future generations and how we wish many many such wonderful days to come for them too. They will thank us for our efforts on their behalf, i cant imagine what they will think of these hateful contemptuous climate killers who stalk the land and Drill or Drop today?



                • Phil C
                  Thanks for the question. My apologies for not finding that question earlier.

                  I can see it was part of a fiery exchange.

                  You ask Nic ‘what is your explanation of a trailing event’

                  And to the professor that you have not had ‘explanation of the issue of trailing events’.

                  In my opinion

                  The good news is that the term trailing events is a construct used in the traffic light system to identify seismic events after fracking has stopped ( by observation of the diagram in the latest frack plan, but not clear in the simplified ‘DECC’ picture ).

                  The issue of trailing events is that ( as I read from the various exchanges ) when the public hear that the event has occurred after fracking has stopped, they may incorrectly assume that the event is not connected to the fracking. An impression re I forced by media interviewed with the operator.

                  I would agree with anyone who preferred the term ‘post fracking events’ if that ties it to the frack in the minds of the public, or indeed any other term that would be suitable.

                  Re creepy, just think of it as an FOI.

  3. Apologies for the delay in responding. The hydraulic fracturing plan for PNR2, approved recently by the Environment Agency (version 3),
    requires the operator to reduce well pressure and pause injection for 18 hours for trailing events at or above 0.5ML. Link is here: To check, see appendix 4.
    I’ll try to post Professor Styles’ diagram in a separate comment.

      • It was DECC or them acting under instruction from higher up, who simplified the TLS and I was very, very angry at the time (and in fact still am! but I am a grumpy old man). I only found out when I attended a meeting at which I gave a presentation and someone from DECC whos name I forget gave the simplified version which has been the source of much of the confusion which has attended the last few years.

  4. Many thanks to Professor Peter Styles. It is disgraceful that this term “trailing event” is being used by industry when it is clearly wrong and misleading. I do hope that Professor Styles shares this information widely.

    • Thanks Professor Peter Styles, now we know what Cuadrilla has been trying to hide all this time, i can see why you were so very very angry the time and you still are.

      What is doubly insulting is that even this watered down version is too difficult for them to work with and their further efforts to water it down even further. that is utterly outrageous.

      Do you think that there is any leeway in getting the watered down TLS back to its original state as you designed it to be? Government and the OGA and the EA need to be told that it is now not as you and your colleagues designed it to be?

      Clearly this is deliberate and secretive watering down of the TLS needs to be spread far and wide amongst all the interested parties.

      • I have given more than 100 talks on this from local groups to the House of Lords ( who listen far more carefully, ( both the WI and the Upper House!!) and ask much more incisive questions than Members of Parliament do), and including to all of these organizations such as the EA and I always, I repeat always, show the original suggested TLS and tell them that what was implemented was NOT what we suggested and that the simplified version is not fit for purpose but………..”.there’s none so deaf as them that want to” be as my dear Northumbrian Granny often said.

        • Peter – I attended one of your talks and was incredibly impressed by the way that you explained the composition of fracking fluid to the lay person with a live cooking class. I thought you also did a good job of explaining seismicity to them – although that is a difficult one because it’s a difficult concept for the layperson to understand.

          I guess one shouldn’t spend too much time mulling over the rights in wrongs of ones previous assessments. However, may partner is very much interested in this subject and he keeps wondering whether your suggestions for the TLS would be the same now given the extra information available. At the time when your report was written much of the information from the USA suggested that events over 1 Ml weren’t common. However, we know now that such events weren’t detected due to the type of geophone used. There was also the feeling in the community that 0.5 separated tensile from shear events. The focal plane solutions of the lower magnitude events now show that most below 0.5 detected have a strike slip motion or are related to bedding parallel shear. As scientists we know that one has to re-evaluate interpretations when faced with new data. Surely the TLS should be reviewed with you having a big part in that review.

            • Peter – indeed it will concentrate minds. I’m not surprised at a 2.1 Ml. One has to remember that it’s small compared to those caused by mining and we will expect larger ones with geothermal, energy storage etc. Your more nuanced TLS proposal in terms of longer flow back for larger events seems prophetic. I just think the 0.5 starting point is very low now that we know that loads of events of this magnitude occur when fracking in the USA and these haven’t caused any problems.

        • Thanks Peter, it is interesting that several posts here from the fossil fuel camp, indicated that the TLS as it stands is not valid at all in their minds, and that it could be watered down even further, or even done away with altogether?

          What i find most fascinating Peter, is that you and your team, who designed the TLS system are saying entirely the opposite, that the present watered down TLS is not fit for purpose and should be strengthened back to its original intended design criteria as you and your colleagues intended it to be.

          that truly puts an entirely new perspective on the claims of the fossil fuel lobby, and that is extremely important for any future debate, such as it is, on the TLS and its present weakened state and the disinformation as to trailing events.

          • PhilC – Maybe you should start reading the newspapers because it’s certainly not the view of Brian Baptie that the TLS is too watered down. The last time I met him he expressed totally the opposite opinion.

            • The opinion of Brian Baptie isn’t of any value relative to Professor Peter Styles and his team who designed the TLS in the it’s correct and stronger form than the watered down version that was changed behind everyone’s backs by whoever “Judith?” darling.

              I will always agree with Professor Peter Styles and his team’s factual definition of the TLS as it was designed to be, and that the TLS must be returned to its full design strength rather than Brian Baptie’s subsequent opinion that even the mysteriously watered down version can be even further watered down into a travesty of gold standard world class disfunctionality and ineffectiveness thank you very much.

          • Judith. I find it hard to understand if 2.1 occurs with the current TLS system in place it is at all helpful to suggest the 0.5 limit be raised. This is crazy thinking. It would encourage higher pressure higher volume fracking by an industry which clearly doesn’t give a damn and which neither understands nor cares about the geology. This can only worsen the current situation. If you are saying you are happy for local residents to suffer far greater seismic events I can only deplore your cynicism.

            You are fully aware that the situation in the US is used by the industry if it pleases them to say it is not relevant, when it does otherwise to say this is what we should judge by. We are not YET the US 51st state, and the best we can do is judge by our own experience, but informed by the experience in other countries. Before 2011 it was flatly denied that fracking caused seismic activity. Then focus shifted to injection as potential culprit. Only recently has the full lesson of Preese Hall been learned. Except, that is, by Cuadrilla.

            Your reference to geothermal or energy storage is a distraction and a spurious argument, as you well know. If I am run down by a car my relatives would be little consoled by saying it would be worse if I were run down by a bus.

            And by the way, no, we don’t want the fracking lorries here. And no, I never did claim that seismic activity was the worst effect of this industry, as I am sure you know after reading my 2013 book Fracking The UK, which has no place in the UK, especially the Fylde.

            • Alan, I don’t see why it is spurious to bring in geothermal and energy storage. We all want to move towards a low carbon economy and it would be ridiculous to impose conditions that will limit our ability to do so. Surely, no one can argue that it’s ok to generate seismicity in one industry and not another. It seems totally sensible to use learnings from the USA and identify which of these are reasonable analogues and which are not. For example, talking about leakage from storage ponds, poisoning the ground water with chemicals added to the fracking fluid is clearly silly as neither would be allowed in the UK. However, taking learning such the relationship between fracking and seismicity is sensible. We need to have a look at all places in the world and understand what controls seismicity and the USA is a good place to start but one needs to take into account that the geophones used to monitor microseismic in the USA weren’t good for measuring events above 1Ml.

              The 0.5 Ml limit is 2 orders of magnitude lower than anywhere else in the world. It was suggested as a way to deal with Preese Hall and was never intended to be rolled out across the UK. It was a temporary measure that needs to be reviewed by experts in the field.

              I know that having bought a house in the area you won’t like more lorries. Everyone seems to want energy and produce without the inconveniences that go with them.

              • Yours is an intellectually sterile argument, Judith. The central fallacy is that we are not talking here about the relationship of fracking with other industries. We are talking purely and simply about the O&G industry.

                The USA is the worst place to start when talking about controls, especially when we are told we have gold standard regulation far better than the US situation. If you want me to look at the US sitiuation, I already covered that in my books. I am not rehearsing all the detailed history and argument contained in those.

                Don’t give me the “silly” BS about ground water etc. BS on two grounds. I never have brought that up in this discussion, so you raise the ususal straw man argument. Secondly you try to persuade us the regulation is better here than in the US. My research, and our experience over the last few yearas is that is a nonsense. Regulations can be are are being broken by an industry that doesn’t give a damn, encouraged by lax eor non-existence enforcement regimes.

                Re Preese Hall I hope you have been sobered up by your exchange with Prof Styles on the TLS system. So even with the current TLS system we are back in a seismic event over 2ML. Fuck the rest of the world. In the UK we have an industry that neither knows the geology or is prepared to adhere to standards. Fracking is not viable and most of us know it. Which is why we are vary angry at any old tom dick and harry trying to impose it unwillingly on us.

                Lorries? I was brought up in the Fylde. You know squit about me. You have not done your research. No we need to reduce energy which is why people like you neither understand nor care about our concerns. [Edited by moderator]

                • Alan, of course you don’t want to talk about other industries because fracking is your obsession and you don’t want to be seen using the silly argument that seismic limits are fine for one industry and not another. However, we are talking about the subject of induced seismicity and it doesn’t matter how that was generated. You seem typical of the antis who simply refuse to look at fracking a wider context so that an informed risk-based assessment can be made on where we obtain our energy. Instead, they generally just say renewables and again refuse to acknowledge huge problems that we face making that transition.

                  It was you that brought up the USA and accused us of cherry picking evidence from the USA to support our arguments. I was simply providing an argument as to why some comparisons are justifiable and other are not. I’ve experienced the regulatory framework in Texas first hand and I know that it’s far slacker than ours on just about every level. I’ve not worked outside of Texas so I don’t know what it’s like there but having visited the places I can certainly see that there are many things allowed over there that are simply not allowed here.
                  It’s great that you have an ability to judge the viability of a shale gas play. I certainly don’t know anyone in industry who can do that based on the data that we currently have. Maybe you should change your profession from amateur researcher to gas company consultant and share with them your deep inside knowledge.

                  In terms of your comments about “f**k the rest of the world”, it’s me that’s making the argument that we should produce our own energy. In that sense it’s you that is saying “f**k the rest of the world”. You seem to not care that others might object to having to produce the energy, or the critical elements needed to create the energy, that use. But NIMBYS do find it difficult seeing further from their back yard.

              • “The 0.5 Ml limit is 2 orders of magnitude lower than anywhere else in the world. It was suggested as a way to deal with Preese Hall and was never intended to be rolled out across the UK”

                Judith here is what was actually written in the Styles/Baptie report

                “The induced seismic protocol mitigation system proposed for future treatments in the Bowland shale is based on work from extensive EGS experience of similar activities (Majer et al., 2008) and may be considered as “industry best practice”. ”

                So your contention that it was never intended to be rolled out beyond PNR is absolute rubbish.

                • Refracktion – I’ve never asked Peter what his intention of the report was but certain one of the his co-authors gave a presentation at which many were present, including the ex-shale gas commissioner, in which he categorically stated that his belief was that the initial report was intended to deal with the area local to Preese Hall. Maybe you should get to know some of the people involved in this subject and then you might be slightly better informed

                • Initially, of course, there only was Preese Hall but I always assumed that we would learn and evolve and that we were attempting to produce a system which would be useful for the UK and potentially elsewhere as well. I had already been working since 1980 on induced microseismicity and its use for controlling events in coal-mines and the stability of landslides and so this wasn’t a one-off as far as I was concerned. We have still only had a handful of fracked wells and so there is still a great deal to learn but the rest of Europe is far behind the UK.

                  Cuadrilla to give them credit where credit is due, have installed a great deal of monitoring equipment but are bearing the brunt of being the first but c’est la vie!

                • Peter has already explained, but to be absolutely clear a induced “seismic protocol mitigation system proposed for future treatments in the Bowland shale” can hardly be described by any person who understands English as being intended to be limited one site.

                  Nice try, but oops you did it again!

        • Why do Cuadrilla have the wrong version of the TLS on their web site?

          Is it so they can justify carrying on fracking?

          In October 2018, Reuters reported that @CuadrillaUK “continued production after a ‘trailing event’: “Cuadrilla said one was a so called “trailing event” which didn’t stop production.”

          By seperating the events over 0.5 ML into pumped and trailing, they halved the number of times they had to stop fracking in 2018 from six to three by labelling events over 0.5 ML occurring after pumping as trailing events,
          In doing so , it’s clear from the Reuters report quoted that they were able to dodge the TLS and continue production at least once.

          • Lock the gate

            The Cuadrilla web site is not likely to be the repository of their controlled documents for site operations. More a place for the public to access them. As such there is likely to be a delay in their appearance.

            The key issue would be that they have the updated plan and are working to it.

            However, it would have better for the public if that plan had been available sooner.

            Re stopping fracking, I do not think you are correct. Any event over 0.5 stops fracking. It seems that you can restart fracking sooner than if following the Prof Styles chart, and not so soon comparing pnr1 to PNR2.

            This is just my interpretation of the various frac plans.

      Additional Information
      Did You Feel It?
      DATE 24/08/2019
      ORIGIN TIME 22:01:35.2 UTC
      LOCATION 53.788 -2.965
      DEPTH 2 km
      MAGNITUDE 2.1

      Felt by several residents in Great Plumpton, Westby, Weeton, Peel, Wesham, Blackpool and Lytham St Annes.

  5. Anyone know when the last fault lubricating frack was? Whereabouts as to the frack injection point. More exact locations of the epicentres, their relationship to the seismic discontinuities (aka faults) in the hydraulic fracture plan. Is the BGS to release this data…

  6. I consider the term “trailing events to be a useful one”, if only to delineate between events that occur whilst injecting, and those that occur post injection. It does not imply, as some have done on this thread, that industry has introduced this term (I actually do not know who first coined the term) and is attempting to avoid linking the trailing events to fracking. The term trailing event certainly goes back around a decade, possibly earlier, and has been described from Canadian examples (e.g. Horn River Basin). With respect to CO2 injection, modelling has long taken into account pressure fronts emanating out from injection points & the possibility of inducing delayed seismic events some distance away from injection sites- but in these cases the volumes of injected fluids are far greater than in fraccing, are cumulative (fluid is not returned to surface) & into porous reservoirs.

    Readers may not be aware of this useful paper published recently, by Clark et al. 2019 I also want to draw attention again to the fact that no event so far associated with fraccing at Blackpool is out of line which is happening naturally in the region, such as the shallow seismic event offshore from Fleetwood last month (2.4 at 3km depth 14km NW of Fleetwood, at 10.54 am July 11th 2019. Nor are the “felt” tremors from fraccing on the Fylde any where near what is already daily experienced from human activity in densely populated areas such as Central London. BGS were involved in this study – so PhilC I don’t think they need to measure ground vibrations from Blackpool trams to prove my point.

    I think it important to put things in context with what is already experienced by many in the UK. Including my own house (in this case ground vibration from agricultural machinery/traffic & natural earthquakes). Indeed when giving evidence to MPs alongside Brian Baptie earlier this year, at Portcullis House, the building vibrated every few minutes due to the Jubilee Line trains, on cue as I was speaking!

    • Nick, I agree that it’s good to separate events into those that occur before and after fracturing a stage of only to help gain a fuller understanding of how seismicity relates to fracking. It’s probably wrong to think that the actual processes responsible for these events differ. I think the main worry is that it seems to have given the ill-informed a reason to think Cuadrilla are in some way trying to cover something up which couldn’t be further away from the truth.

      • Nick and Judith, both of whom I respect greatly, I am going to have to disagree with you here.

        When Operators, when interviewed after an event which, while small by any global standards, is perceived as being disturbing by the populace state: “We weren’t fracking at that time”, that leads to the obvious conclusion that they are attempting to make a significant distinction between the two different kinds of events and more importantly that they either consider or are trying to imply that they have less responsibility for the second “trailing ” events. I controlled/mitigated catastrophic failures in anthracite coal-mines using real-time seismic monitoring in the 1980s (Wales and Australia) and so I have a very clear understanding of what the issues are and the complexities.

        This wasn’t a convincing example of the success of that strategy as applied here.

        • Peter, Thank you. Well Cuadrilla must speak for themselves, and we do not know how things were edited in the media. I know that I have had journalists completely change the meaning of what I have said by editing. Some of these journalists I now refuse to work with. Trailing events are induced by fraccing, the fact they are called trailing – implies they are related. As regard the populace being concerned. I think a proportion of this concern is due to some in the anti-frack community overstating things & thereby inducing fear in the population, plus the media needing a story. So, I think some in the industry, academia, campaign movements & media have some element of blame in terms of what & how & when they communicate to the public, & what the public then perceive.

    • [Edited by moderator]

      Have you investigated the offshore O&G exploitation on the Irish Sea off our coast to state categorically that the local seismic events are “natural”?

      Again, we are not convinced by your London arguments. We don’t live in London. We don’t want to suffer the degradation of our environment Londoners face. We live in an area which says no to everything you are saying, every comparison you make means nothing to us. When you and others back off and realise your scientific credentials mean squit (do you really think your qualifications make you more knowledgeable or better than us?) you may start to have more respect for your ideas.

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