Lars Sørum: The three perceived risks of fracking

Posted: August 13, 2013 by tallbloke in alarmism, Shale gas

From risk management company DNV

Lars Sørum, Director of Shale Gas, DNV:

The below three issues are in my opinion the most important only because they are the most debated. Let’s be clear; the risks associated with unconventional gas are not significantly different from those of conventional exploration. Nor are the most relevant risk areas below ground, but on the surface and mostly non-technical . So the reason to highlight the below as the top 3 challenges is related to the “perceived risks” rather than the “actual risks”. These perceptions in turn can topple the best of business plans and are therefore still pretty important. Important are also the economics of a unconventional business – but in this piece I figured I would stay with the “popular ones”, also covered in DNVs Recommended Practice, which gives guidance to this and other issues.


The “groundwater” issue

Does hydraulic fracturing contaminate ground water? First of all one must see this in two separate parts 1) contamination by chemicals and 2) contamination by methane. To address the first, water contamination by chemicals does occur, but so far this has proven to be due to poor lining of pits or other surface spills rather than the hydraulic fracturing itself. For the second point there have been several papers on this issue most notable and in the public eye important is the Osborne et al (2011) paper. They concluded that the closer a home was to a shale gas well, the higher the average and maximum methane concentrations in drinking water wells, has been widely disputed most notably by Molofsky et al (not peer reviewed article 2011). They criticised the Osborne study for the lack of baseline data, and sampling volumes amongst others and concluded that gas development activities (in the Marcellus Shale) have not caused widespread methane impacts on water wells. Other critiques, including those from the gas industry, opined that the study did not adequately establish that the methane found had the signature of the relevant shale formation where the hydraulic fracturing was done, or that the mechanism by which the methane reached the wells was related to gas extraction processes. Recent studies claim that ground water may contain methane contamination due to poor casing and cementing or poor monitoring of wells, procedures and management and these are certainly issues that need careful design and execution, but importantly that is still not related to hydraulic fracturing – the focus on this technology as a hazard may therefore be somewhat misplaced. Importantly, biogenic methane occurs naturally in most ground water. The thermogenic methane that may stem from shale is what needs to be measured – it’s all about the isotopes! In any case, the health effects of methane contamination needs more research to be concluded as a major issue.

The “greenhouse effect” issue

The second issue that is in the public debate is the issue of methane slips to the atmosphere and the CO2 emissions that stem from the energy use for shale gas operations. Howarth et al (2011) concluded that due to the fugitive emissions of methane the greenhouse gas footprint of shale gas is larger than that of conventional gas, oil, and also larger than that of coal (over a twenty-year time horizon). These conclusions were significant because they challenged the characterisation of shale gas as a “bridge fuel”. Personally I would challenge that in general terms – gas is a destination fuel; full stop! Two papers published shortly after the Howarth et al paper contradicted those conclusions (Carnegie Mellon University and another paper by Dr. L. Cathles, another Cornell professor). The Carnegie paper used a fugitive emissions estimate of 2%, which is small compared with Howarth’s range of 3.6 to 7.9 %. The Cathles response attacks Howarth’s paper for “significantly” overestimating fugitive emissions and ignoring the use of green completions, or application of technology that has been used for years by industry to reduce and, ideally, eliminate fugitive emissions. Later papers ordered by the EU Commission for Environment (AEA 2012) concludes that fugitive methane emissions from hydraulic fracturing and management of flow back waters are sources of GHG emissions that do not arise from conventional extraction – and would be in the range of 1-3% higher than for conventional gas extraction. However, they also conclude that no relevant data is available for Europe as no production takes place at present and that although Shale gas E&P with hydraulic fracturing is an established technology in the US there remains a lack of clear, detailed data to provide the evidence base for determining emission factors for specific sources. In any case it seems clear that there is nothing inherently different with the molecules of gas from shale that makes it more susceptible to leaking from pipelines and valves. The greenhouse gas issue is still important for the industry, and there is considerable efforts underway by utilities in the US to tackle this growing problem.

The “earthquake” issue

A third issue which has been raised, particularly in the press and most notably in the UK, is that of induced seismicity by hydraulic fracturing and although felt seismicity is extremely rare, micro- seismicity does occur and is used as the primary tool to monitor the success of hydraulic fracturing process and the extent of the hydraulic fracturing system. The recorded events related to hydraulic fracturing is mostly related to reinjection of fluids rather than the fracturing itself. Below a few kilometres depth (where hydraulic fracturing normally occurs) the earth crust is stressed and those natural stresses put faults close to failure. When injected at high pressures fluids are forced along faults making a triggered earth tremor more likely. The formation of new fractures (the hydrofracture itself) does not appear to release much energy compared to the “triggered quakes” but large volumes of fluids that are injected during disposal may create earth tremors (Green, Styles et al 2012). Examples of such induced seismicity is recorded in a number of different operations ranging from gas recovery to water reservoirs and mining activities over decades. Green, Styles et al concluded in their report to DECC 2012 that maximum magnitude of induced events is not likely to exceed magnitude 3 that may be felt, may in rare circumstances cause superficial damage (plaster) but not structural damage.

  1. michael hart says:

    “The thermogenic methane that may stem from shale is what needs to be measured – it’s all about the isotopes!”

    You’ll frighten the horses talking about isotopes 🙂 A number of people will need reassuring that they are not radioactive.

    I don’t see the relevance of speculating about methane leaks from pipes: the UK has been using natural gas in most of the country for many decades now. I guess that this is a speculative concern imported from US environmentalists where there is much less domestic experience of using piped gas as a fuel.

    Similarly with concerns about water wells: much domestic UK water does not come out of wells, and I don’t think fracking is likely in areas that extract water from chalk aquifers.

  2. michael hart says:

    And earthquakes? I think many in the UK would be quite excited by an occasional small tremor to relieve the monotony. Unfortunately I don’t think they would feel the earth move from fracking. A local train might have more effect 🙂

  3. craigm350 says:

    The greenhouse gas issue is still important for the industry, and there is considerable efforts underway by utilities in the US to tackle this growing problem.

    A ‘problem’ that exists only in climate models. Hans von Storch
    we find that the continued warming stagnation over fifteen years, from 1998-2012, is no longer consistent with model projections even at the 2% confidence level

  4. Roger Andrews says:

    The objections to fracking listed above are red herrings.

    Over the last few years the warmists have suffered a number of setbacks, including Climategate, the lingering death of the Kyoto Protocol, the refusal of the earth to warm up as predicted, the refusal of extreme weather events (except maybe freezing winters) to increase as predicted, the failure of the Indian Ocean to inundate the Maldives and the continued refusal of the public to realize how dangerous global warming is (the January 2013 Pew Poll again showed global warming coming last in a list of 21 priorities for US voters, and according to the UK Polling Report the percentage of UK respondents who thought that human activity was making the world warmer fell from 55% in 2008 to 39% in 2013).

    And now here comes fracking, which threatens to destroy the “peak oil” myth and thereby eliminate arguably the last remaining excuse for converting the world to green energy. And what makes it worse is that fracking reduces emissions. Because of gas produced by fracking the USA – which Jim Hansen calls a “rogue state” because of its refusal to adopt emissions control legislation – has in fact reduced its CO2 emissions more than any other industrialized nation over the last few years.

    No wonder the Greens don’t like it.

  5. Jaime Jessop says:

    The EPA found evidence of water contamination from fracking operations in 1987. It is a little ‘odd’ that they have recently abandoned their to-be-peer-reviewed study into groundwater contamination in Wyoming and left the investigation there to the local authorities.

    I think labeling water contamination as merely a ‘perceived’ risk is stating only one half of a truth. Yes, it is perceived to be a risk; additionally it is a real potential hazard of fracking and finally a demonstrable occurrence in many fracking operations.

    My other main concern with this ‘dash for gas’ is the fact that it being sold by Camoron as the ‘cure’ for our sky-high energy bills. This may or may not actually prove to be the case, but the fact is, Camoron’s obsession with being the ‘greenest government ever’ is the direct cause of those sky-high energy bills. If he had got it right on energy supply from the moment he got into power and not let LibDem idiots like Huhne and Davey formulate energy policy, we might not be in the parlous state we are today, with power cuts and energy rationing on the horizon and ever spiraling bills. Nuclear has been all but abandoned. Conventional, far less controversial domestic oil and gas reserves seem to be taking a back seat, e.g. And there is still plenty of ‘filthy’ cheap climate-busting coal left in the ground!

    I predict that, rightly or wrongly, protests against fracking are going to escalate until the government is forced to scale down the ambitious scale of fracking operations in this country. It is probably twice as unpopular and even more emotive an issue than windfarms. Even if the risks are overstated, I do not think that the government is going to be able to sell large scale fracking to a public deeply disenchanted with politics, politicians and energy policy in particular. This is all a consequence of the dreadful mismanagement of our energy supplies by successive governments and the scandalous manner in which vested corporate interests have been allowed to corrupt political decision-making on this most vital of issues.

  6. Roger Andrews says:

    Jaime Jessop: You say “(water contamination) is a real potential hazard of fracking and finally a demonstrable occurrence in many fracking operations.”

    Could you please provide some specific examples?

  7. Jaime Jessop says:

    Roger, aside from the 1987 EPA study:

    “A 2004 EPA study concluded fracking did not pose a risk to drinking water, helping lead to its exemption from the Safe Drinking Water Act through the Energy Policy Act of 2005. The study was later criticized as limited and compromised by oil/gas industry influence. A 2009 ProPublica investigation found that contamination was far more prevalent than indicated in the report, citing more than 1,000 cases tied to drilling and fracking that had been documented by courts and state and local governments.[3]”

    The EPA have also been accused of censoring their study in Dimock, PA which found elevated levels of methane in the drinking water of residents close to a fracking site.

    I’m sure that fracking proponents would like to dismiss these findings as ‘unscientific’/insignificant and label the questioning of the behaviour of the EPA in this matter as the outpourings of ‘conspiracy theorists’, but the point is, it is not easy to dismiss all of the available evidence which strongly suggests that fracking does contaminate water nearby fracking sites.

  8. Richard111 says:

    Hmm… seems a lot of the original complaints against fracking arose from poor working practices. Will be very difficult to convince people these problems have been resolved. Just for fun ask people you meet, say in the pub or at a football match, “Do you know what an isotope is?”
    Can someone advise me on the number of ‘thumps’ per well? I assumed just one but possibly another may be needed if supply pressure is low. Either way it’s not as if they will be blasting for ever more.

  9. Roger Andrews says:


    I’ve been digging through the web for most of the day trying to find a case where fracking has been demonstrated to have caused groundwater contamination but haven’t been able to find one. And while I thank you for the three examples you provide I’m still batting .000.

    The best information I’ve been able to come up with is in a 2011 MIT study that reviewed 43 “widely reported” incidents of contamination in several thousand fracked gas wells drilled in the US between 2005 and 2009 ( MIT’s conclusions were:

    “Of the 43 widely reported incidents, almost half appear to be related to the contamination of shallow water zones primarily with natural gas. Another third of reported incidents pertain to on-site surface spills. In the studies surveyed, no incidents are reported which conclusively demonstrate contamination of shallow water zones with fracture fluids.”

    “The fracturing process itself poses minimal risk to the shallow groundwater zones that may exist in the upper portion of the wellbore. As described previously, multiple layers of cement and casing protect the freshwater zones as the fracture fluid is pumped from the surface down into the shale formation. This protection is tested at high pressures before the fracturing fluids are pumped downhole. Once the fracturing process is underway, the large vertical separation between the shale sections being fractured and the shallow zones prevents the growth of fractures from the shale formation into shallow groundwater zones. Table 2.4 describes the typical separations in the major
    shale plays; in all but one case there are several thousand feet of rock — typically sandstones and shales, many of which have very low permeability — separating the fractures shale formation and the groundwater zones. It should be noted here that only shallow zones contain potable water; as depths increase, the salinity of the groundwater increases to the point that it has no practical utility.”

    So if fracking didn’t cause the groundwater contamination, what did?

    “Leakage of natural gas or drilling fluids into shallow zones … appears to be the most common cause of reported incidents, and it is generally associated with drilling and setting the surface casing. There are three potential risks during this phase of operation: (1) overweight drilling mud causing some drilling fluid leakage into groundwater zones; (2) unexpected encounters with shallow gas zones with the possibility of gas migration into groundwater zones and (3) poor quality cementing of the surface casing, allowing a potential fluid pathway into the groundwater zones during subsequent operations.”

    None of these risks, however, is generated by fracking. And 43 incidents in thousands of fracking operations is hardly a doomsday scenario anyway.

    So I thank you for having driven me to do this research, which places me squarely on the side of the pro-frackers.

  10. braddles says:

    Something that causes micro-earthquakes is likely to be a good thing if it relieves existing crust stresses. Damaging earthquakes occur where crustal stresses build up over long periods and cannot be relieved.

  11. Jaime Jessop says:

    Roger, I tried Bing as a search engine instead of Google and came up with the following links. It would appear to be the case generally that the greater risk of water pollution is from the surface operations rather than the shale fracturing itself. I am not nearly so convinced that fracking is safe as you are. I quote: “In fact, the study shines a light on the fact that there are a number of aspects of natural gas development that can pose significant environmental risk. And it highlights the fact that there are a number of ways in which current regulatory oversight is inadequate.” from this source:

    The full report can be found at:

    Finally, a list of incidents where water contamination near fracking wells has been reported but not meticulously investigated. You may argue that such cases are purely anecdotal and therefore not proven, but there are a hell of a lot of them and even this list is not exhaustive. You can click on the links in each report for further information. Many of them involved lawsuits. I would think if they were totally inconsequential or impossible to link with fracking activities, they would not have passed the hurdles for due legal process.

  12. Roger Andrews says:


    We move closer to common ground.

    The MIT study I linked to earlier found cases where ground and surface water contamination could be linked to poor drilling practices, surface spills etc. but none where it could be linked to fracking, and the University of Texas study you cite found the same thing. The title of the Environmental Defense Fund article that reports the results of this study sums it up: “If The Problem isn’t (Fracking), Then What Is?”

    The scope of the “Problem” is set out in your second link (this time from the Natural Resources Defense Council) which cites 37 cases where local residents allege contamination related to fracking operations. As you note, these cases are “anecdotal” and not “meticulously investigated”, and based on the information supplied there’s no way of confirming that the contamination was caused by fracking. A brief review, however, suggests that most if not all of these incidents were also related to poor well drilling practices. (Some of them were also probably included in the 43 incidents investigated by MIT but I don’t know this for sure.)

    So where does this leave us? Well, fracking isn’t fail-safe – nothing is – but it’s clearly getting a bum rap. The environmental problems everyone associates with it seem to be related mostly to poorly-completed wells that were drilled before the fracking began – in some cases long before – and the solution is to make sure any such wells are properly sealed before fracking begins.

    Another interesting question is why people have suddenly become so worked up about fracking, which has been going on in one form or another in the USA for 150 years. Maybe more on this later.

  13. tchannon says:

    Coal mining is historically present but that is much shallower. Leaks CH4 as well.

    I think the water contamination issue is overblown, live with it. Equating what happens in sparsely populated and little developed places such are rural US is for a variety of reasons very different.

    The UK mostly has an advanced if old infrastructure which includes piped processed water so any problem shifts to professional suppliers who watch for contamination anyway. Can be handled as strategic planning.

    Raw usage might be agricultural. Is this an issue?

    Natural springs? I don’t doubt seepage has been going on since the ice age.

    Lets put this a different way, you expect gas etc. to make it through a layer of eg. millstone grit, then through coal seams in sufficient flow to pose actual problems?
    Roughly speaking the upper shale is a mile down, the lower shale two miles down.

    Water for eg. Manchester comes from where?
    Things like this
    Apparently the longest tunnel in the world, 95 miles, no pumps.

  14. tallbloke says:

    My dad did civil engineering work on the pipe from Thirlmere that supplies Manchester. Working out the max head for getting the siphon over the hills was interesting. Cavitation is an unrelenting thing. Too much suction and the gas is pulled out of the water and breaks the siphon.

  15. tchannon says:

    Many suns ago we tried to find some of the Roman syphons which crossed the Rhone valley, in lead apparently.

    Here is one we never found. (Internet might have helped)

    2000 years later we have progressed…

  16. […] of Shale Gas, at internationally renowned risk management company DNV dispels the three myths in a well considered report. Our membership needs to read these two experts findings, and join in the fray, helping to allay […]