Research

Geologists challenge oil companies’ comments on Surrey earthquakes

surreyquakesmap_bayes_map Stephen Hicks

Map of earthquake cluster in Surrey. Source: Stephen Hicks https://sphicks.weebly.com/2018-surrey-uk-earthquakes.html

Statements made by two oil companies about the recent cluster of earthquakes in Surrey have been challenged by geologists.

Angus Energy and UK Oil & Gas, who operate near the centre of the earthquakes, have both said their operations could not have caused the 14 small earthquakes recorded near Newdigate since 1 April 2018.

Dr Stephen Hicks, a seismologist at Southampton University, tweeted earlier this week that some of the science and facts on Angus Energy’s website “doesn’t completely add up”.

180814 Stephen Hicks tweet 1

Emeritus Professor David Smythe questioned Angus comments made to a county council meeting that it was “scientifically impossible” for its operations at Brockham to cause the earthquakes. Professor Smythe has also called on UK Oil & Gas to produce evidence of what it described as a “large fault”, around which the earthquakes were clustered.

DrillOrDrop invited Angus Energy and UK Oil & Gas to respond to the challenges. UKOG replied but declined to comment. Angus Energy read our emails but did not reply.

Yesterday at 5.30pm, DrillOrDrop took screen grabs of the Angus Energy web page on the earthquakes. At some point afterwards, the web page was updated and statements challenged by Dr Hicks have been rewritten. (Click on images from the screen grabs taken yesterday, left,  and those taken today, right).

 

Who said what? (and when)

“Physical impossibility”

Andrew Hollis, of Angus Energy, said in an advertorial in Surrey Live 10 days ago:

“it is physically impossible for the Brockham field to create an earthquake”.

Paul Vonk, Angus Energy’s Managing Director, told  a meeting of Surrey County Council last week:

“It is scientifically impossible for the Brockham oil field to cause the earthquakes. There is no physical connection between the fault at Brockham and the earthquake area”.

Professor Smythe, in a review of the Surrey earthquakes said:

“injected fluid from Brockham BRX-3 could, in principle, flow south (or north) along the high permeability reservoir, crossing through any faults on the way, and aided by confining clays (layers of low permeability) above and below.”

He added that research from the US had shown that fluid pressure from injection was linked to induced earthquakes observed more than 20km away, albeit with large volumes of fluid.

“Lowest intensity”

Up to 5.30pm yesterday, Angus Energy said on the FAQ page of its website that the Surrey tremors have “the lowest intensity possible on the Mercalli Scale. The USGS describes all of these earthquakes as “Not felt except by a very few under especially favourable conditions.”

180815 FAQ hightlight intensity

Screen grab of Angus Energy web page from 15 August 2018

Dr Hicks said:

“The shaking intensity felt during the largest earthquakes in the swarm wasn’t “the lowest intensity possible”. Actually, shaking intensity of level 4 on the European Macroseismic Scale was felt during the 05/07 event and reported by the BGS. This shaking intensity scale goes from 1 (Not Felt) to 12 (Completely Devastating) Other earthquakes in the sequence had ground shaking intensities of level 3; other earthquakes in the swarm were not felt. Shallow depth of earthquakes = higher shaking intensity over a small area.”

At the time of writing, the Angus Energy web page had changed to say:

“All of these tremors were magnitude 3 or below which means that most people would not notice them even if they very [sic] close to the centre. In general, these sorts of tremors would not cause any surface effects.

“Floating on magma”

180815 FAQ hightlight magma

Screen grab of Angus Energy web page from 15 August 2018

Up to 5.30pm yesterday, Angus Energy said on its web page:

“Earthquakes and tremors are naturally occurring phenomena. We live on a thin solid crust, plates which are floating on a big layer of molten rock (magma).”

Dr Hicks said:

[The] “earth’s crust does not “float on magma”. Earth’s mantle, which is the layer below the crust, is actually pretty solid. It is not molten. It only flows and creeps very very slowly on geological timescales – over millions of years.”

At some point after yesterday evening, Angus Energy removed the whole sentence on magma from its web page.

Distance from the epicentres

Up to yesterday evening, Angus said on its web page:

“The epicentres of these earthquakes are ~10.5km to the south of the site.”

Dr Hicks said:

“The nearest and best-located earthquakes of the sequence are ~7 km distance from the Brockham drill site – not 10.5 km. Still a fairly long way away, but it’s good to get these distances right so that we’re being consistent.”

Since yesterday evening, Angus Energy changed its web page to say:

“The centres of these tremors ranged from 6.9 to 10.4km to the south of the Brockham Field with the scatter of centres around 9.3km to the South.”

“North-south tremor”

180815 FAQ hightlight southgate

Screen grab of Angus Energy web page from 15 August 2018

Angus originally said on its web page:

“We couldn’t cause a North-South tremor even if Gareth Southgate told us to. Again, this is plain science.”

Dr Hicks said:

“The phrase “north-south tremor” just doesn’t really make any sense.”

Angus Energy has since removed the reference to the “north-south tremor” and Gareth Southgate. At the time of writing, the web page said:

“To be clear, there cannot be any link between production and water replacement in Brockham and these events. This is because the Brockham field is sealed to the south by a fault. If this fault did not seal there would be no oil there. So oil and water cannot move from the Brockham field anywhere to the south.”

Fracking and earthquakes

Up to yesterday evening, Angus Energy said on the web page:

“It is clear hydraulic fracturing or ‘fracking’ risk creating tremors. Angus Energy does not frack. Nor is there any fracking in Surrey, period.”

Dr Hicks said:

“Yes, hydraulic fracturing and high-rate wastewater disposal are the biggest cause of induced earthquakes in the oil/gas industry, but there is no acknowledgment [in the FAQs] that examples exist of conventional production causing earthquakes e.g. due to reservoir depletion.”

Since 5.30pm yesterday, Angus Energy has removed this reference.

Faults and tremors

Stephen Sanderson, the executive chairman of UKOG, told BBC Radio Surrey:

“the data that I’ve looked at shows that these tremors were actually clustered around quite a large fault which comes to the surface around Russ Hill”

Professor Smythe said he had found no faults near Russ Hill on maps from the British Geological Survey or geological Roam data. He said:

“I therefore challenge Mr Sanderson to produce evidence for his alleged “large fault”. If he cannot do so, the impression seems to be left that he is once more prepared to come out with any old nonsense in order to defend his company and support the share price.”

So what do we know?

Dr Hicks concluded on his website:

“Based on our knowledge of activities at the nearby drilling sites of Horse Hill and Brockham, as well as our knowledge of human-induced seismicity around the globe from the scientific literature,  there is no clear reason why these earthquakes should have been directly caused industry. Injection volumes and pressures appear to be too low, whilst the distances and timescales involved do not indicate a clear, physical link.

“Whilst earthquakes have been shown to be induced over long distance and timescales due to fluid injection in Oklahoma, the injection rates and volumes are much higher than what we know to have occurred in the Weald Basin.

“Overall, there is no substantial evidence at present which indicates that these earthquakes have been directly induced by nearby industrial activities.”

Professor Smythe concluded on his website:

“the extreme shallowness of the Newdigate events means that we have a lot to learn about shallow pore pressure, shallow stresses, and shallow faults. The complex tectonic problem to be resolved here lies in the depth zone of the hydrocarbon activity.”

He backed a call for a moratorium on oil operations in the Weald by a group of geologists earlier this month (DrillOrDrop report)

“In view of the clear temporal and spatial relationship to the current exploration and production activity at the two sites in question, I support the call for a moratorium on further hydrocarbon activity made by four expert earth scientists.”

Links

Twitter feed for Dr Stephen Hicks

Dr Stephen Hicks website about the Surrey earthquakes

Professor David Smythe’s website

Angus Energy revised web page on the Surrey earthquakes

17/8/18  First quote from Professor Smythe changed from “along the low permeability” to “along the high permeability”

28 replies »

  1. “Based on our knowledge of activities at the nearby drilling sites of Horse Hill and Brockham, as well as our knowledge of human-induced seismicity around the globe from the scientific literature, there is no clear reason why these earthquakes should have been directly caused (by) industry. Injection volumes and pressures appear to be too low, whilst the distances and timescales involved do not indicate a clear, physical link.

    “Whilst earthquakes have been shown to be induced over long distance and timescales due to fluid injection in Oklahoma, the injection rates and volumes are much higher than what we know to have occurred in the Weald Basin.

    “Overall, there is no substantial evidence at present which indicates that these earthquakes have been directly induced by nearby industrial activities.”

    Paul & Ruth – What is the story here? Personally I thought there might have been a link – but now I am sure there is not. Even The great Emeritus cannot come up with a link.

    • The story is that Angus Energy wrote a load of garbage and had to be corrected. As clearly highlighted by DoD.

  2. In one of the quotations above I describe the (Portland Sandstone) reservoir as low-permeability. It should of course read:
    “injected fluid from Brockham BRX-3 could, in principle, flow south (or north) along the high-permeability reservoir”.
    I have corrected my blog accordingly. Thanks Ruth for making me see this error.

  3. In reply to Messrs Tresto and Seddon, I think the ‘story’ is fairly evident. Something highly unusual is happening at shallow depth in the sedimentary pile, involving rock stresses, fluid extraction and injection, and earthquake triggering. The near-coincidence in time and space points to a possible connection with the nearby hydrocarbon exploration and production activity, but we earth scientists do not yet understand what (if any) the link is. That is why there should be a moratorium on such activity until the problem is resolved.

  4. For the Private Eye readers out there, sounds like a case of Sandersonballs and Vonkballs. Twaddle from people who really should know their subject but clearly don’t.

    The terrible thing is that those Vonkballs soundbites will lodge in their acolytes heads and be presented as scientific truth. Do stop it. I know your businesses are on the line, fellows, but do let the experts do their work.

  5. does anyone trust what volumes Angus Energy say they have reinjected into wells. [Edited by moderator] They don’t even have to keep detailed records. Gold Standards my arse.

    • Presumably you are referring to David Smythe who had to be resubmitted to access his university accounts after efforts at banning him by Younger etal were found to be unjustified and illegal. Considerable expense to the University in ‘exposing’ Smythe to be bona fide with rational views substantiated by well researched evidence …

    • I suggest, Mr/Ms ‘Johnson’, that you think very carefully before describing me as “discredited” – a word which appears nowhere in the article from 2014 that you cite.

      It is typical of people like you yourself, Prof Paul Younger of Glasgow University, Stephen Sanderson of UKOG, and others, that because you are unable to question my science you go for character assassination instead. I took legal action against my University to get my online academic access restored, following Younger’s internal manoeuvring to have it terminated. At a preliminary hearing last year the Sheriff ordered Glasgow University to restore my access within 24 hours, and (unusually) awarded all costs against Glasgow. Paul Younger took early retirement last year and died in March 2018, so he is no longer around to answer for his actions. The new Secretary of the University, settling the case out of court with my costs of £12,547 paid in full, wrote:

      “I am writing to confirm that as an Emeritus Professor of Geophysics, College of Science & Engineering, University of Glasgow, you are entitled to continue to use that title without hindrance. … For my part, I regret the recent dispute between the University and yourself … I have no reason to doubt your integrity as a scientific researcher, and hope that you will continue to be as productive in your research as you have been since your retirement in 1998.”

      Contrary to the false claim made by Younger back in 2014, I was indeed made a Chartered Geologist in 1990, but never used the appellation CGeol after 1995, having stopped paying the exorbitant annual fee to the Geological Society of London for the privilege.

      Regarding my Solid Earth Discussions paper, it was not thrown out – it remains published online, having been approved for discussion by the topic editor. But it required too much revision and covered too many subject areas for the editor to cope with, even though I had successfully answered the many comments. I still intend to resubmit a revised paper covering a small part of its subject matter, but will publish other topics it contained elsewhere.

      Regarding my research productivity cited by the University Secretary (above), for a period of several months earlier this year I was THE ‘most read’ researcher out of all the 11,000 researchers at the University registered on ResearchGate, which is a sort of Facebook for academics. So Younger, in consort with the right-wing press, had connived to have all my research – evidently of considerable worldwide interest – terminated, just because he disagreed with my views on fracking. Fracking comprises a small part only of my overall research output.

      Let’s get back to the exploration geology now, shall we? I am still waiting for UKOG to admit that:
      • their geological understanding of Horse Hill is severely flawed;
      • proximity to the Horse Hill Fault accounted for the temporary high flow rate;
      • Broadford Bridge-1 and -1z were both technical failures, caused by drilling through the Broadford Fault;
      • Sanderson’s claim of a “large fault” at Rush Hill is spurious.

      Alternatively UKOG can try to refute in detail my analyses. In addition, the OGA must publish its evidence for asserting that there is no link between current activity and the earthquakes.

  6. What a load of rubbish, remember the days we used to have coal mines. tunnels underground to the coal face large enough for a train to go through, where high explosives were used to blast the coal face smithereens on a daily basis, Where were all the earthquakes with this work ? Far more intrusive to mother earth than a six inch bore hole. and yet nothing. What were getting is just normal mother earth with hiccups.

  7. Was this “evidence”, or much of it, not presented recently at a Planning Meeting? What was the result of that Planning Meeting?

    Doesn’t seem to have achieved much traction there, so let’s try to excite through another route.

    Good job that BGS are on the case and quietly getting on with their on the spot analyses. I feel more inclined to follow their independent science than that of an anti activist. But, for those who prefer hypotheses, rather than on the spot analyses they have a choice.

    As yesterday’s survey publication showed the majority of those anti to fracking don’t have a good knowledge of the subject (yes, the Weald is not fracking but it is being presented as such) so fertile ground for hypotheses.

    Notice some comment about depletion of reservoir being a possible concern! Someone, is ‘avin a laugh, I would suggest! What are the estimate figures for the reservoir content, and how much has/is depleted?

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