Hydraulic fracturing in the United Kingdom

Hydraulic fracturing
Shale gas drilling rig near Alvarado, Texas
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Hydraulic fracturing in the United Kingdom has been used in conventional North Sea oil and gas fields from the late 1970s. It has been used in about 200 British onshore oil and gas wells since the early 1980s. The technique did not attract interest from the public until licences use were awarded for onshore shale gas exploration in 2008.^[1] Although hydraulic fracturing is often used synonymously to refer to shale gas and other unconventional oil and gas sources, it is not always correct to associate it with unconventional gas.^[2]

In the United Kingdom, as in other countries—and in particular the United States, where the industry is most advanced and widespread, hydraulic fracturing has generated a large amount of controversy.

In January 2014, the European Commission issued a set of recommendations on the minimum principles for the exploration and production of hydrocarbons from shale formations using high-volume hydraulic fracturing.^[3] It recognises that it can be an economic boost but there is a need to not repeat the pollution incidents that have occurred in the US.^[4]

In late May 2011, the first UK exploration for shale gas using high-volume hydraulic fracturing was suspended at Preese Hall in Lancashire after the process triggered two minor earthquakes.^[5] The larger of the earthquakes caused minor deformation of the wellbore^[6] and was strong enough to be felt.^[7] The report of 2012 by the Royal Society and the Royal Academy of Engineering concluded that earthquake risk was minimal, and recommended the process be given nationwide clearance, although it highlighted certain concerns,^[8] that lead to a raft of regulation for the industry.^[9] A detailed briefing paper was issued in late 2015 for the Houses of Parliament. This gives a full review of current thinking.^[10]

History

The first experimental use of hydraulic fracturing was in 1947, and the first commercially successful applications of hydraulic fracturing were in 1949.^[11]

Offshore

In the United Kingdom, the first hydraulic fracturing of a North Sea well was carried out shortly after discovery of the West Sole field in 1965. After the industry started to use of intermediate- and high-strength proppants in late 1970s, hydraulic fracturing became a common technique in the North Sea oil and gas wells. The first hydraulic fracturing from ship was conducted in the British Southern North Sea in 1980, with massive or high volume hydraulic fracturing used from 1984 onwards.^[12]

Onshore

Approximately 200 onshore wells have been hydraulically fractured, around 10% of all onshore wells in the United Kingdom, including Wytch Farm, which is the largest onshore oil field in western Europe.^[8] The surge of public interest in high-volume hydraulic fracturing in the UK can be traced to 2008, when Cuadrilla Resources was granted a Petroleum Exploration and Development Licence (PEDL)^[13] in the 13th Landward Licensing Round ^[14] for shale gas exploration along the coast of Lancashire^[15] The company's first and only high-volume hydraulic fracturing job^[16]:4 was performed in March 2011, near Blackpool, Lancashire.^[17][18] Cuadrilla halted operations in May 2011 at their Lancashire drilling site due to seismic activity damaging the casing in the production zone.^[19]

From 1977 until 1994, a hot dry rock geothermal energy experiment was conducted in the Carnmenellis granite of Cornwall. During that experiment, three geothermal wells with depth of 2.6 kilometres (1.6 mi) were hydraulically fractured.^[20]

Method

Hydraulic fracturing is a well-stimulation technique in which rock is fractured by a hydraulically pressurized fluid. A high-pressure fluid (usually chemicals and a proppant suspended in water) is injected into a wellbore to create an extensive system of small cracks in the deep-rock formations through which natural gas, petroleum, groundwater (in the case of water wells) and brine will flow more freely. In horizontally drilled sections, it is common to perform as many as 30 separate fracture stages, to evenly divide the production zone. When the hydraulic pressure is removed from the well, small grains of hydraulic fracturing proppants (usually sand but aluminium oxide, or ceramic beads may be used) hold the fractures open when the pressure is released. The bulk of the additives are usually the proppant, up to 10%, but other chemicals designed to reduce water viscosity, and to modify other fluid properties may also be added, at quantities typically less than 1% in total. One of the main differences between hydraulic fracturing in different countries is the usage of chemicals. As of December 2014, the only chemical additives that have been permitted by the Environment Agency in the United Kingdom were 0.075% of polyacrylamide friction reducers, 0.125% hydrochloric acid and in rare cases 0.005% biocide.^[2]

Gels, foams, and compressed gases, including nitrogen, carbon dioxide and air can be injected in place of water. Fracturing fluids have been developed using liquefied petroleum gas (LPG) and propane in which water is unnecessary. There is sometimes a need to fracture at shallower depths in coalbed methane wells and these methods can be used.^[21] The extent of natural fracturing in the coal would determine if this was necessary. Hydraulic fracturing methods such as these will use a much smaller volumes of fluid.^{[22][23][24][25][26]}

Microseismic monitoring of fracture growth

Microseismic monitoring techniques, using very sensitive microphones and tilt meters can monitor the growth of fractures in the target formation in real time. This can be done using a surface array, or, if there is a nearby offset well, using downhole microphones. This means that the engineers can modify the pump rate based upon the growth of the fractures, and stop pumping if there is evidence of vertical migration into faults. This technology is available from many big oilfield service companies.^[27]

Understanding pressure

When a well is hydraulically fractured, or when any injection is carried out, this is done through a production packer (seal), and is done through the drill pipe or tubing. Fluids are circulated down the tubing, to below the point where the packer is sealed against the production casing. Pressure is then be applied only that part of the casing below the packer.^[28] The rest of the well casing will not experience any increase in pressure due to the sealing of the packer. The surface casings do not experience the great pressures experienced at the production zone. This means the stresses on a surface casing are no greater than on a normal oil or gas well. Smaller diameter pipes can sustain much larger pressures than large diameter pipes.

Areas where hydraulic fracturing used

Although the first shale gas well was drilled in England already in 1875, only high volume hydraulic fracturing^[29] combined with horizontal drilling is likely to enable commercial extraction of unconventional hydrocarbon resources, such as shale gas and light tight oil, in the United Kingdom.^[8][30][31] The largest resource is expected to be the Upper Bowland Shale of the Pennine Basin in Lancashire and Yorkshire.^[31]

A BGS/Department for Energy and Climate Change (DECC) report from May 2014 suggest that there is the possibility for the extraction of light tight oil (LTO) in Weald Basin and the average figure of 4.4 billion barrels (700 million cubic metres) is suggested. The overall range of estimations is from 2.2 to 8.6 billion barrels (350 to 1,370 million cubic metres). The data is said to have a "high degree of uncertainty", and the amount that could be produced is unknown, and could be zero.^[32] Celtique Energie plans to apply for a permit to drill a test to an oil-bearing shale of the Weald Basin in 2014.^[33]

The Durham Energy Institute has produced an evaluation of the potential impact and likelihood of drilling in environmentally sensitive areas. The main areas of interest are the North York Moors NP, the Peak District NP, the South Downs NP (principally shale oil) and Yorkshire Dales NP.^[34]

Hydraulic fracturing of geothermal wells

The Eden Project in Cornwall is in the process of drilling and hydraulically fracturing two geothermal wells for utilisation of geothermal energy as a source for a geothermal power station.^[35]

Regulation

Guidance for operators to obtain licences for various aspects of drilling was published in August 2016 ^[36]

There are separate regulatory authorities in Scotland,^[37] Wales^[38] and Ireland^[39]

There are a variety of Government Agencies involved in regulation. Between 2008 and 2016, the Department of Energy and Climate Change (DECC), was one of the key Departments to grant permission. This department was abolished in July 2016, and the responsibilities have been absorbed by the Department for Business, Energy and Industrial Strategy.^[40]

It is required that chemicals used must be available for public examination "Chemicals used in drilling and hydraulic fracturing fluids are assessed for hazards on a case-by-case basis for each well by the appropriate environmental regulator (EA, NRW or SEPA). Operators must declare the full details of the chemicals to the regulator and will publish a brief description of the chemical’s purpose and any hazards it may pose to the environment".^[16]

Another regulator on the engineering issues is the Health and Safety Executive. Examination of a brief of their regulations show that well design must be approved by the HSE and then sent to an independent Well Examiner.^[41] Under current regulation, the 'independent' Well Examiner can be an employee of the operating company, as identified in the RAE report.^[42]

In the event of a poor cementation remediation must involve expert opinion of the Well Examiner. Poor cementation has been identified in the RAE report as one of the main pollution paths and sources of surface gas leaks in the US.

The British Geological Survey (BGS) are involved with monitoring potential environmental hazards.^[43][44]

Local Councils also have some regulatory powers, with regard to planning permission. These are generally limited to concerns such as traffic and noise. These can be overturned on appeal.^[45]

The Minerals Planning Authority (MPA) will determine if an environmental impact assessment (EIA) is required. This would be funded by the operating company.^[9]

The regulatory process has been set out in publications and guidelines on techniques and practices from the industry body, UKOOG.^[46] There are also requirements for community engagement.^[47] The industry currently has to comply with 17 European Directives, has to apply for up to nine separate environmental permits and has to reach binding agreements on noise, hours of operation and other local social issues. In compliance with the industry’s engagement charter, each operator engages with the public at six points during the pre-consultation, planning and permitting stag.^[48]

In January 2014, an impact assessment by the European Commission concluded that existing legal and regulatory environments were insufficient, and recommended a new directive with specific requirements for high volume hydraulic fracturing to address: "environmental risks and impacts"; allay "public concerns", and; "enable investments".^[49]

The regulation of hydraulic fracturing in the UK has been criticised by the chemicals policy charity CHEM Trust, who argue that it is not sufficiently protective.^[50] They also raise concerns about reducing resources for the regulators of hydraulic fracturing, like the Environment Agency. The United Kingdom Onshore Oil and Gas (OKOOG) trade association challenged the CHEM Trust analysis,^[51] and CHEM Trust then responded to the issues raised by UKOOG.^[52]

Differences between the US and UK

In the United States, regulation of oil and gas drilling and production is largely left to the states, and differs from state to state. In 2005 in the US Congress, at the behest of then Vice President Dick Cheney (citation needed), a former CEO of Halliburton, exempted hydraulic fracturing from the underground injection regulations of the Safe Drinking Water Act.^[53] This meant that any chemical except diesel, and including toxic, non-toxic and carcinogenic materials were permitted to be injected into an oil or gas well to stimulate the well, and public disclosure of these was not required.^[53]

There are also differences in fluid security that mean that open fluid storage is not permitted in the EU or the UK. Venting of unburnt gases is also not permitted, except in an emergency.^[16]:4[54]

Paying for regulation

The costs of inspections by the Environment Agency, and the HSE can be reclaimed from operators by those agencies.^[55]

The HSE and EA have an agreement concerning the inspection of critical processes.^[56]

The Infrastructure Act 2015

In February, the Infrastructure Act 2015 received royal assent. The bill covered many aspects of hydraulic fracturing, and permits hydraulic fracturing under homes, without consent. The legislation is limited to the petroleum and geothermal industries.^[57]

This also included clauses on maximizing economic recovery of UK petroleum ^[58] on meeting climate change requirements ^[59] and changed the definition of hydraulic fracturing to more than 1000m of fluid per stage ot more than 10,000m in total. In addition conditions were attached that mean no hydraulic fracturing can take place at a depth shallower than 1000m, and that soil and air monitoring must be put in place. Another clause states 'the associated hydraulic fracturing will not take place within protected groundwater source areas' ^[60]

Environmental impact

In 2012, the Government commissioned a report to identify the problems and advise regulatory agencies. Jointly published by the Royal Society and the Royal Academy of Engineering, under the chairmanship of Professor Robert Mair, the report included recommendations on groundwater contamination, well integrity, seismic risk, gas leakage, water usage and disposal, management of environmental risk, implementation of best practice, and various management and regulatory issues.^[8] According to Professor Mair,"well integrity is of key importance but the most common areas of concern, such as the causation of earthquakes with any significant impact or fractures reaching and contaminating drinking water, were very low risk" but the report stated adequate regulations must be put in place. The RAE report stated, "Many claims of contaminated water wells due to shale gas extraction have been made. None has shown evidence of chemicals found in hydraulic fracturing fluids". This report lead to a Government paper^[61] that outlined the requirements of the regulatory framework.

An operator needs to seek planning permission from the local minerals planning authority (MPA). The MPA/LPA/DOE will determine if an Environmental Impact Assessment (EIA) is required.^[9][36] EIAs cover a wide range of concerns, including habitat damage, effect on wildlife, traffic, noise, lighting, and air pollution. This reference shows one example ^[62] These are presented in less detail in a ' Non Technical Summary'.^[63]

In any event, the Environment Agency require that environmental risks due to drilling are evaluated prior to issuing licences to operate.^[36]

In October 2014, EASAC stated that: "Overall, in Europe more than 1000 horizontal wells and several thousand hydraulic fracturing jobs have been executed in recent decades. None of these operations are known to have resulted in safety or environmental problems" ^[64][65]

A report from AMEC^[66] in December 2013 covers many of the environmental issues that would arise were the shale gas industry to become highly developed.

The Chartered Institute of Environmental Health (CIEH) and Scientists for Global Responsibility (SGR) published a report about hydraulic fracturing that was broadly negative. It referred to major shortcomings in regulatory oversight regarding local environmental and public health risks, the potential for undermining efforts to tack climate change, and the possibility that the process might cause water shortages.^[67] The report received some negative academic reviews based upon the main author being a Green Party candidate, and hydraulic fracturing protestor, and the alleged selective nature of some of the data used.^[67][68]

The ReFine consortium from Durham University has produced a series of short video presentations taking an independent academic view on the science of shale gas production. These cover the topics 'What is Shale Gas?', 'Hydraulic Fractures, how far can they go?' 'What sized earthquakes can be caused by fracking?', 'An overview of shale gas risks', and 'Fracked or Friction?'.^[69]

The British Geological Survey are involved with environmental monitoring.^[70]

The Environment Agency released its licencing protocols in August 2016.^[36]

Air pollution

There are concerns, originating in the USA that drilling could lead to pollution from hydrocarbon based chemicals.^[71] Regulations in the UK call for total fluid and gas security meaning that in routine operations, no unburnt gases would be emitted.Venting of unburnt gas is only permitted for safety reasons or in an emergency.^[72][73]

In 2014, Public Health England stated "evaluated available evidence on issues including air quality, radon gas, naturally occurring radioactive materials, water contamination and waste water. They concluded that the risks to public health from exposure to emissions from shale gas extraction are low if operations are properly run and regulated."^[74]

Flaring

Information about gas flaring can be seen here

Water

One potential pollution path is from leaks on the surface through spillage. The Environment Agency requires chemical and fluid proof drill pads, as well as other environmental protections.^[36][75]

The DECC document 'Fracking UK Shale, Water' indicates how operators must address issues water usage, and pollution potential, treatment of flowback water, together with the mitigation measures and links to well regulation requirements.This includes requirements to "make appropriate plans for storing fluid safely, and not in open pits , design the site so spills are avoided (and are contained if they do happen), and dispose of flowback fluid safely" ^[16]

In January 2015, the British Geological Survey released national baseline methane levels, which showed a wide range of readings^[76] Poor surface well sealing, which allows methane to leak, methane was identified in the Royal Academy of Engineering report as a risk to groundwater. They recommended "To detect groundwater contamination, the UK’s environmental regulators should work with the British Geological Survey (BGS) to carry out comprehensive national baseline surveys of methane and other contaminants in groundwater. Operators should carry out site-specific monitoring of methane and other contaminants in groundwater before, during and after shale gas operations".^[61] This was incorporated into the Infrastructure Act 2015 withh a requirement that monitoring takes place 12 months before fracturing.^[77]

The Chartered Institution of Water and Environmental Management (CIWEM) have been involved with evaluating the potential water impacts of hydraulic fracturing and drilling.^[78]

Groundwater contamination

The joint Royal Society and Royal Academy of Engineering report from 2012 indicated that the distances between potable water supplies and fractured formation in various US shale plays is large, meaning the risk of contamination is very small. No cases of pollution by this route have been identified. Considering the conditions in the UK, the report concluded: "The very unlikely event of fractures propagating all the way to overlying aquifers would provide a possible route for fracture fluids to flow. However, suitable pressure and permeability conditions would also be necessary for fluids to flow. Sufficiently high upward pressures would be required during the fracturing process and then sustained afterwards over the long term once the fracturing process had ceased. It is very difficult to conceive of how this might occur given the UK’s shale gas hydrogeological environments. Upward flow of fluids from the zone of shale gas extraction to overlying aquifers via fractures in the intervening strata is highly unlikely".^[8]

In 2013, the ReFINE consortium published an information video on the potential for aquifer contamination via vertical fracture growth and suggested a minimum distance of 600m between the aquifer and the horizon being hydraulically fractured.^[79]

Examining the maximum potential vertical growth of fractures, a 2012 research paper from ReFINE concludes that "The maximum upward propagation recorded for a stimulated hydraulic fracture to date is 588 m in the Barnett shale in the USA. Based upon the data presented here the probability that a stimulated hydraulic fracture extends vertically beyond 350m is approximately 1%. Very few natural hydraulic fractures pipes or simulated hydraulic fractures propagate past 500 m because layered sedimentary rocks provide natural barriers to growth."^[80]

The Infrastructure Act 2015 'prohibits associated hydraulic fracturing from taking place at a depth of less than 1000 metres'^[81]

Research by Engelder et alia in 2012 on the Marcellus shale formation, indicated that any water injected into the shale that does not flow back to the surface, known as "residual treatment water", would be permanently absorbed, (sequestered) into the shale.^[82] Shale has no natural porosity that could hold water.

Flowback fluid

Disposal and treatment of flowback fluid is regulated by the Environment Agency.^[36] Flowback fluid contains high levels of salt and is contaminated with organic "solids, heavy metals, fracking chemicals and naturally occurring radioactive material (NORM) of varying concentration and low levels of radioactive materials".^[83] The Environment Agency strategy for management of NORM-contaminated flowback fluid, after treatment, includes its preferred re-use by re-injection during hydraulic fracturing^[84] and its disposal, with caveats, via water treatment sites ^[85]

Flowback fluid can be treated and reused in later hydraulic fracturing operations,^[84] to reduce the volume of freshwater required and to mitigate issues arising from off-site disposal of flowback fluid.^[86] Flowback fluid injection in deep disposal wells, which has been linked to significant increase in earthquake rate,^[87] is not currently licensed in the UK by the Environment Agency.

In January 2014, licences were withdrawn by Cuadrilla when arrangements for disposal and treatment of contaminated flowback fluid were not considered to be adequate by the Environment Agency.^[88] Technologies are developing methods of removing salt and radioactive materials, allowing safe disposal of flowback fluid under Environment Agency licence.^[89] Research in the US also indicates new methods such as "microbial capacitive desalination cells" may become available.^[90]

UK and US water differences

Treated mains water is the norm in the UK, and standards are required by legislation to be high. As such any pollution would have to be removed by the water companies by law. Private water wells are rare, around 62,000 households, out of 23.4 million households or 2.6%.^[91] In rural areas of the US, private wells are common (15%), and small communities are served by investor-owned utilities, or community schemes. UK households would therefore be expected to be less at risk than those in the US.

In the US, baseline methane measurements were not made at the start of the shale gas boom, meaning that it became difficult to prove whether a gas problem was due to a leaking well, or was naturally occurring.

Water depletion

The DECC report Fracking UK Shale-Water states that water companies must produce, and then update every 5 years, a long term plan with contingency reserves in case of a drought. Water companies will assess the amount of water available before providing it to operators.^[16]

DEFRA data^[92] indicates the amount of water abstracted nationally, at around 16 billion cubic metres. The DECC report shows the usage expected for hydraulic fracturing a well.^[16] It is equivalent to watering a golf course for a month. Evidence presented by the Environment Agency to the Parliamentary 'Environmental risks of fracking inquiry' indicated water usage at a peak level would be 0.1% of national usage.^[93][94]

Some living in drier areas, in East Kent, for example, are concerned about the effect of hydraulic fracturing in using large volumes of scarce water supplies.^[95] East Kent falls within the Environment Agency's Southern Region, the third-driest region of England and Wales.^[96]

Land usage

Directional drilling allows a large hydrocarbon reservoir to be accessed using a single well pad, such as in Europe's biggest onshore oilfield, Wytch Farm.Vertically drilled fields, like the Jonah Gas field, will have a larger surface impact, but would not be likely in the UK due to planning restrictions. Likely well spacing visualised by the December 2013 DECC Strategic Environmental Assessment report indicated that well pad spacings of 5 km were likely in crowded areas, with up to 3 hectares per well pad. Each pad could have 24 separate wells. This amounts to 0.16% of land area.^[97]

Permitted chemicals

Only 'non-hazardous' chemicals are permitted for hydraulic fracturing fluids in the UK by the Environment Agency (EA). The nature (though not the concentration) of these chemicals must be made available to the public.^[16]:4

The European wide Groundwater Directive is European legislation that states. In order to protect the environment as a whole, and human health in particular, detrimental concentrations of harmful pollutants in groundwater must be avoided, prevented or reduced. ^[98]

The Environment Agency regulations state Groundwater’ means all water that is below the surface of the ground in the saturation zone and in contact with the groundwater or subsoil (EPR, Regulation 2(1)).

‘Aquifer’ means a subsurface layer or layers of rock or other geological strata of sufficient permeability to allow either a significant flow of groundwater or the abstraction of significant quantities of groundwater (WFD Article 2.11.2016)

Under EPR Schedule 22, paragraph 6 we must take all necessary measures to: (a) prevent the input of any hazardous substance to groundwater; and (b) limit the input of non-hazardous pollutants to groundwater so as to ensure that such inputs do not cause pollution of groundwater. The Environment Agency would not authorise the use of a hazardous substance for an activity, including hydraulic fracturing.

The pollutants the Environment Agency are concerned with for groundwater are: ‘Hazardous substances’, which are substances or groups of substances that are toxic, persistent and liable to bioaccumulate, and other substances or groups of substances that give rise to an equivalent level of concern (EPR Schedule 22, paragraph 4). Any non-hazardous pollutants, which is ‘any pollutant other than a hazardous substance (EPR, Schedule 22, paragraph 5).^[99]

Substances on List I of the binding Groundwater Directive (80/68/EEC) are taken to be hazardous substances ^[100][101]

The Environment Agency list of chemicals does not contain all of those that may be proposed in hydraulic fracturing. The regulations above indicate that authorisation would be decided on a case by case basis, using the above protocols.^[16]

In the Preese Hall 1 well, the chemical concentration was 0.05%. However, when millions of gallons of water are being used, the amount of chemicals per fracturing operation could be large. For example, a 4 million imperial gallons (18,000 m³) hydraulic fracturing operation would use at 1%, 180 tonnes. At 0.05% this would be 9 tonnes. The main additive is polyacrylamide, the purpose of which is to reduce the viscosity of the water, to allow faster pumping. Additional chemicals that have been permitted are highly dilute hydrochloric acid, a sodium tracer salt and glutaraldehyde, which is used as a biocide in very small quantities, to kill bacteria that could damage a well. This rapidly breaks down into non toxic materials. It is not necessary to use this if domestic water, treated with chlorine, is supplied, as this will be bacteria free anyway. Ultraviolet germicidal irradiation is another replacement available to treat water.

Although some of the chemicals used in hydraulic fracturing fluids such as hydrochloric acid may be classified as toxic,^[102] corrosive or irritant, they are non-toxic at the concentrations used.^[103]

Although hydraulic fracturing was not proposed in a well at Balcombe, the Environment Agency permitted one requested chemical oxirane, while not permitting the use of antimony trioxide which is suspected as being carcinogenic.^[104]

Seismicity

As of August 2016, there were six known cases of hydraulic fractured wells that are likely to have induced quakes strong enough to be felt by humans at the surface: In Canada, there have been two suspected events in Alberta (M 4.8 and M 4.4),^[105] two in British Columbia (M 4.6 and M 4.4), one in Oklahoma, US (where several felt quakes were associated with a single fracked well); and one in Lancashire.^[106]

The graphic above from the Department of Energy and Climate Change shows that this level of seismicity approaches levels where property damage could occur.

In December 2015, the Centre for Research into Earth Energy Systems (CeREES) at Durham University published the first research of its kind, prior to "planned shale gas and oil exploitation", in order to establish a baseline for anthropogenic, induced seismic events in the UK.^[107]

ReFINE produced a video on seismic risk ^[108]

In Feb 2016, Stanford Earth published video to explain the situation and why seismicity has occurred in waste water disposal from traditional oil wells, but also small amounts of frack waste water. See UK injection information

Preese Hall, Lancashire

In May 2011, Cuadrilla voluntarily suspended^[109][110] hydraulic fracturing operations in their Preese Hall 1 well in Lancashire, after two small earthquakes were triggered, one of magnitude M 2.3.^[111] The largest coseismic slip caused minor deformation of the wellbore^[6] and was strong enough to be felt.^[7]

The company's temporary halt was pending DECC guidance on the conclusions of a study^[112] being carried out by the British Geological Survey and Keele University,^[109] which concluded in April 2012 that the process posed a seismic risk minimal enough to allow it to proceed with stricter monitoring.^[113] Cuadrilla pointed out that a number of such small-magnitude earthquakes occur naturally each month in Britain.^[114]

Cuadrilla commissioned an investigation into the seismic activity, which concluded that the tremors were probably caused by the lubrication of an existing fault plane by the unintended spread of hydraulic fracturing fluid below ground.^{[115][116][117]}

In 2012, a report on hydraulic fracturing produced jointly by the Royal Society and the Royal Academy of Engineering noted that earthquakes of magnitude M 3.0, which are more intense than the larger of the two quakes caused by Cuadrilla are: "Felt by few people at rest or in the upper floors of buildings; similar to the passing of a truck."^[8] The British Geological Survey has published information on seismic issues relating to hydraulic fracturing.^[118]

In February 2014, following the small seismic event in the Preese Hall 1 well, and much research, the DECC issued a statement on earthquake risk.^[5]

Subsidence

There is no documented evidence of hydraulic fracturing leading to subsidence.^[5] Operations are commonly monitored with tiltmeters, and no compaction issues have been documented. Given the mechanical properties of unconventional rocks (their densities, low porosities, low Biot coefficients, and high stiffness), compaction is very unlikely to occur during hydrocarbon extraction.^[119]:18 Subsidence has occurred in conventional gas fields very rarely, but only when the reservoir pressure of free gas was very high, and partially supporting the overlying formations. This is not the case with shale gas. One such case is the Groningen field in the Netherlands. Homeowners are to be compensated for subsidence encountered in this shallow but highly productive gasfield.^[120]

House insurance

In an answer to questions from the 'Lets talk about Shale'^[121] initiative from the industry body, UKOOG, they have stated "According to the Association of British Insurers there is, at present, little evidence of a link between shale gas and property damage, and they are not aware of any claims where seismic activity as a result of fracking has been cited as a cause of damage. Damage as a result of earthquakes, subsidence, heave and landslip are all covered, in general, under buildings insurance. Insurers will continue to monitor the situation for the potential for fracking, or similar explorations, to cause damage."^[122]

It was reported in early 2015 that farms would not be covered by issues that may arise due to hydraulic fracturing. A clarification by the insurer indicated that this would only apply to a farmer that permitted this on their land. Surrounding farms would be covered.^[123]

Public health effects

Public Health England's Dr John Harrison, Director for Radiation, Chemical and Environmental Hazards, stated: "The currently available evidence indicates that the potential risks to public health from exposure to emissions associated with the shale gas extraction process are low if operations are properly run and regulated. Where potential risks have been identified in other countries, the reported problems are typically due to operational failure. Good on-site management and appropriate regulation of all aspects of exploratory drilling, gas capture as well as the use and storage of hydraulic fracturing fluid is essential to minimise the risks to the environment and health."^[124]

The campaign group Medact published a paper called the 'Health Impacts of Fracking' which reported health implications from fracking.^[125] This received a negative reaction from the industry group, UKOOG, as it appeared to ignore the UK fracking regulatory context.^[126] This led to a rebuttal from Medact.^[127] In addition, the use of two anti-frack campaigners as authors undermined the objectivity and reliability of the report.^[128] The content of the Medact Report 2015 and other US origin studies that have been publicised in the UK were commented on by Public Health England, in the planning document from Lancashire County Council Planning Department report. This was published to advise Councillors about upcoming fracking decisions. The quality of the research that underpinned the Medact Report 2015 was called into question. PHE reviewed some US health studies and pointed to many flaws in the quoted research, from pages 307 to 313.^[129]

Use of radioactive sources

There have been some public concerns about use of radioactive sources in wells.^[130] The difference between radiation dose and Radioactive contamination seems to be poorly understood. Well logs involving radioactive sources are a legal requirement.^[131]

Well integrity

In the Preese Hall 1 well, the UK's only hydraulically fractured shale gas well (to November 2014), drilled by Cuadrilla Resources, there was poor cementation in the horizontal production zone only. Cement is pumped up the outside of the casing and if the casing is not well centralised, the cement may not seal completely around the casing. Poor cementation, if confined to the production zone, does not create a leaking well, as long as there is good cementation above it, through the cap rocks, or 'regional seals'. The casing in the production zone will be perforated anyway, to allow hydraulic fracturing fluid to flow out of the borehole and into the target formation. The only problem posed by poor cementation in the production zone is that it may reduce the effectiveness of the hydraulic fracturing. The borehole is hydraulically fractured in stages, typically several hundred feet at a time, so if the casing is not well cemented, then the hydraulic fracturing fluid may dissipate into other parts of the productive formation. That may compromise the production of the well, but would not pose a leak or safety issue.^[132]

The well experienced minor seismic events, two of which were felt by humans (Magnitude M2.3 and M1.4). The largest coseismic slip caused minor deformation of the wellbore^[6] and was strong enough to be felt.^[7]

Well leak concerns

In March 2014, ReFINE published a report^[133] that investigated well leak concerns, involving UK's producing, suspended, old, abandoned, and 'orphaned' wells. It included a large number of data sets, from around the world, including some very old well data. There are issues of 'well barrier', where an internal leak is found, that does not leak to the environment, and 'well integrity' where external leaking/venting is an issue. The data provided often puts the two data sets together. In the ReFINE abstract, the percentage of wells that have had some form of well barrier or integrity failure is highly variable (1.9% to 75%). Looking at the most recent results In a separate study of 3533 Pennsylvanian wells monitored between 2008 and 2011, there were 85 examples of cement or casing failures, 4 blowouts and 2 examples of gas venting. A November 2013 paper states Well-integrity failure occurs when all barriers fail and a leak is possible. True well-integrity failure rates are two to three orders of magnitude lower than single-barrier-failure rates..^[134] Another paper from 2012 indicates that the bulk of the environment code violations in recent activity in Pennsylvania are nothing to do with well leaks.^[135]

The response from UKOOG^[136] welcomed the ReFINE report, stating that well leaks in the UK were little problem, and contrasted the small number of orphan wells with the estimated 250,000 abandoned mines.

It is commonly believed that '6% of wells leak immediately, 50% of wells leak after some time and all wells will leak eventually'. This is not an issue specific to hydraulic fracturing, it is a concern with every well that is drilled. This originates from a document that sells solutions for this problem to oil and gas companies.^[137] This often relates to 'SCP', or Sustained Casing Pressure This is a 'well barrier' issue, but could also include casing 'integrity' (external) leaks. Data from DECC^[138] has been released concerning this and of the approx 2000 onshore wells, and approx 6500 offshore well, the number of current recorded leaks is zero, although there was a need for two well integrity repairs. The ReFINE report does also indicate that there is no meaningful data on the bulk of the land based wells, and that only the 143 producing wells have been examined. Regulation calls for baseline monitoring to determine if any leak issues are related to the drilled well.^[139]

A research paper, from 2009 indicates Low cement top or exposed casing was found to be the most important indicator for sustained casing vent flow (SCVF)or gas migration (GM)SCVF/GM. The effect of low or poor cement was evaluated on the basis of the location of the SCVF/GM compared to the cement top. The vast majority of SCVF/GM originates from formations not isolated by cement. ^[140] The current regulations from the HSE are designed to mitigate these concerns, and seal wells back to the surface.^[41]

Concern has been raised about some wells drilled before the latest guidelines that do have potential leak paths. An internal memo shows on page 3 that there is no cement from 1200 feet to the surface aquifer, and as such there is a potential leak path. If the casing were to leak due to corrosion or other reason, there would be a leak path from deep salty formations into the aquifer. In addition the aquifer is only protected by one layer of (uncemented) casing.^[141]

Information from the US Groundwater Protection Council shows that there is a failure rate of around 1 every 3500 wells, or 0.03%.^[142]

If a well were to leak, workover operations can usually fix leaks, by, for instance, perforating the casing above and below a poorly cemented zone, and 'squeezing' cement behind the pipe. The cement is drilled out and a pressure test is performed until pressure integrity is good.^[143]

The 'Fracking' debate

This section has information about concerns that fall under the general public conception of fracking. This term is commonly used to mean any form of hydrocarbon extraction, and is mixed in with the Climate Change debate. The photo shows an 'anti frack' rally at Balcombe, which is an oil well in limestone that had no permission to hydraulically fracture the formation. Others protest using shale gas techniques as a focus, at proposed coalbed methane sites.^[144]

Anti-fracking protesters say that there are various problems associated with the process including pressure on local transport infrastructure, air and water pollution, the amounts of water used, and potential economic damage to agricultural, food production and tourism industries.

Effect on house prices

The possible effect of house prices due to hydraulic fracturing is a highly emotive one due to large amount of capital invested by the owners.

In August 2014, a report called 'Shale Gas:Rural Economic Impacts' was published by the UK Government, in response to a Freedom of Information request, from Greenpeace. It was due for publication in March 2014.^[145][146] It was notable as large parts of this had been redacted, leading to criticism about the transparency of information being provided.^[147] In certain areas of the US house prices have reduced in areas where hydraulic fracturing is taking place, and whether this will affect the market in the UK remains to be seen. The effect was mainly reported to be with houses that used well water, whereas houses that had piped water saw a slight increase.^[148]

Opposition

There are a number of anti-fracking groups,^[149][150] which range from the nationwide Frack Off which was engaged in the Balcombe drilling protest, to local ones such as Residents Action on Fylde Fracking,^[151] Ribble Estuary Against Fracking,^[152] NO Fracking in Sussex, Frack Free Fernhurst^[153] and The Vale Says No!^[154] The Environmental Group Greenpeace publish an online 'live' fracking report^[155] Friends of the Earth are also against Fracking.^[156]

In the UK and Europe, hydrocarbons are government property, so local residents have little to gain from oil and gas drilling; the situation is different in the US, where landowners commonly also own the oil and gas, and so negotiate lease bonuses and production royalties from the oil companies.^[157][158]

In September 2011, with licences having been granted to two energy companies for exploratory drilling in Somerset, Bath and North East Somerset Council voiced concern that, should the test drilling yield a significant find of shale gas, any subsequent hydraulic fracturing could contaminate Bath's famous hot springs.^[159] Similar worries about future hydraulic fracturing have been aired in a number of other places, including the Vale of Glamorgan and Woodnesborough, Kent.^[160][161] Industry assurances about its forthcoming plans were tarnished in January 2012, though, when Cuadrilla Resources came under fire for its categorical denials of plans of hydraulic fracturing near Balcombe after documents from parent company AJ Lucas materialised appearing to indicate the complete opposite.^[162]

In April 2013, "fracking activist" Refracktion reported Cuadrilla's brochure to the Advertising Standards Authority (ASA), who deemed that of the 18 statements made, 11 were acceptable and six had breached the Committee of Advertising Practice (CAP) code^[163] and that the brochure "must not appear again in current form".^[164] In January 2015, two supporters of fracking, Reverend Michael Roberts and Ken Wilkinson, reported an anti-fracking group's leaflet to the ASA. The ASA resolved the complaint with an informal ruling that the group, Residents Action On Fylde Fracking (RAFF), had "exaggerated the size and scale of planned fracking operations"^[165] RAFF "agreed to amend or withdraw advertising without the need for a formal investigation".^[166] In 2015, Cuadrilla, along with a supporter of fracking, reported a leaflet produced by Friends of the Earth to the ASA and to the Fund Raising Standards Board (FRSB)^[167]

In March 2014, a group of conservation charities including the RSPB and the National Trust released a report^[168] containing a 10-point plan for increased regulation, and highlighting concerns about groundwater pollution, industrialization of the countryside, Environmental Impact Assessments, and hydraulic fracturing inside National Parks. The response from UKOOG, the representative body for the UK onshore oil and gas industry ^[169] pointed at 'critical inaccuracies', and stated that the regulation called for was largely in place.

Wales

In October 2011 the campaign to prohibit Coastal Oil and Gas from test drilling at the Llandow Industrial Estate, in the Vale of Glamorgan, met with initial success after local councillors unanimously refused the company's plans, though Coastal immediately indicated it would appeal.^[170] Residents feared that successful exploration would be the prelude for hydraulic fracturing.^[161] The basis of the Council's decision was a letter from Welsh Water stating that there was "a very small risk" of contamination of its reserve groundwater sites from exploratory drilling.^[171] The rejection came despite the Council being told that, strictly from a planning point of view, there were no "reasonable or sustainable grounds" to refuse, and despite the drilling application containing no explicit mention of hydraulic fracturing. The company had additionally claimed that, since the "gas shales in the Vale are not as thick as elsewhere", any discoveries would be "very unlikely" to require hydraulic fracturing for extraction.^[170]

Coastal Oil and Gas decided to appeal to the Welsh Government, rather than undertake legal action against the local authority,^[172] and a public enquiry began in May 2012.^[173] Coastal's chances of success at the enquiry were boosted by Kent County Council approval of the company's near-identical plans for preliminary drilling in Woodnesborough,^[161] and were increased to near certainty after Welsh Water effectively retracted its previous risk assessment.^[173]

Industry response

In arguing its case, Cuadrilla contrasts its approach with the one taken in the United States, claiming that only three chemicals—a polyacrylamide lubricant commonly found in cosmetics, hydrochloric acid, and a biocide used to purify drinking water—will be used in the UK, compared with the hundreds that can be used across the Atlantic; that it has invested in more expensive, better equipment than that used by companies operating in the US;^[174] that its wells have three layers of pipe casing to line the wells, whereas many American ones only have two; that the barrier between the gas escaping up the pipe and ground water is thicker; that cement will be returned to the surface, blocking identified leak paths; and that drilling fluids will be collected in closed steel tanks, rather than in lined earthen pits, as often happens in the States.^[157][175] According to Cuadrilla's communication advisor, "Gasland (the US documentary about shale gas) really changed everything. . . . Before that, shale gas was not seen as routinely controversial."^[174]

Political issues

Hydraulic fracturing has brought with it various challenges for Britain’s political parties. That is particularly the case for the Conservative Party, where there are tensions between the aspirations of the leadership – who tend to view shale gas in terms of economic benefit, energy independence, and a means of reducing carbon emissions – and the priorities of many of its supporters who are hostile to the process, especially those who live in areas likely to be explored for shale gas.^{[176][177][178]}

The Liberal Democrats, in 2013 in a coalition government with the Conservative government which strongly supported hydraulic fracturing, began taking a position downplaying prospects for a "shale gas revolution", issuing several position papers on climate change which minimized the role of shale gas in favour of renewables.^[179] The Labour Party has been more reticent, but MPs have indicated they are receptive to hydraulic fracturing if environmental safeguards and an appropriate regulatory regime are in place.^[180] By contrast, UKIP is enthusiastic about shale gas, a stance that is partly derived from its hostility to wind farms.^[181] The UK Green Party`s energy policy EN264 states that: "We will halt the development of coal-bed methane, shale gas and similar hydrocarbon exploitation since it is not needed to meet UK energy demands, is environmentally destructive, and will lead to increasing GHG emissions".^[182]

As of 2013 the government was solidly behind development of the fossil fuel shale gas industry and was offering to give shale gas companies favourable tax treatment for the unconventional energy source. Also they stated they would turn 100% of business tax proceeds over to local councils instead of the usual 50% which has been seen as controversial in some parts of the media.^[183][184] Green Party leader Natalie Bennett said of the government's proposal to turn the business taxes gained from hydraulic fracturing over to the local councils: "It looks like the government is bribing local councils and it shows how desperate it is to get fracking accepted locally."^[183]

The House of Lords report "The Economic Impact on UK Energy Policy of Shale Gas and Oil" from the Economic Affairs Committee was published in May 2014.^[185] It took evidence on a wide variety of subjects from a wide variety of sources. It concludes that shale gas exploration and development should go ahead urgently, and that the regulatory regime was complex, and a hindrance to growth.

In May 2014, the prospect of drilling under peoples homes was put out for consultation and the resulting report in October 2014 indicated that 99% of 40,000 responses were opposed to this.^[186] The Infrastructure bill, which became law in February 2015, included an amendment that this was to be permitted. The National Farmers Union issued this statement that indicated concerns with property prices, long term environmental issues and payment for access in line with other industries.^[187][188]

The chemical firm Ineos has proposed that they would pay 6% of income in payments for local people, farmers, and landowners. Ineos chairman Jim Ratcliffe said "Giving 6% of revenues to those living above Britain's shale gas developments means the rewards will be fairly shared by everyone." Friends of the Earth said this was a "transparent attempt to bribe communities"^[189]

Conflicts of interest

There have been a number of concerns raised regarding conflicts of interest between policy makers and financial links to hydraulic fracturing, notably Lord Browne of Cuadrilla - The former BP boss is chairman of Cuadrilla, which is exploring for shale gas in Lancashire and West Sussex. He is lead "non-executive" across Government.^[190] Baroness Hogg - The non-executive for the Treasury sits on the board of BG Group, which has significant shale gas assets in the United States. Sam Laidlaw - The non-executive to the Transport Department is also chief executive of British Gas owner Centrica, which recently bought a 25 per cent stake in Cuadrilla's most promising shale gas prospect. Ben Moxham - A former executive at BP when Lord Browne was at the helm, he followed the peer to Riverstone Holdings, which owns 42 per cent of Cuadrilla. Moxham was energy adviser at No 10 but quit in May (year?). Lord Howell - George Osborne's father-in-law is also president of the British Institute of Economics, whose backers include BP and BG Group.^[191] House of Lord's Select Committee on Economic Affairs potential conflicts of interest with regards to hydraulic fracturing. Baron Hollick: Has shares in Samson resources a US company with shale gas investments. Lord Skidelsky: invested in Janus Capital who hold stakes in oil and gas firms Lord Mcfall: Held investments in FTI consulting, fracking industry advisers Baroness Noakes: had shares in at least 3 firms with interests in shale gas.^[192][193] Lord MacGregor or John MacGregor as he was previously known is the current Chairman of ‘The British Energy Pension Fund Trustees and Chairman, Eggborough Power Ltd Pension Fund Trustees, both now part of EDF Energy.^[194] CPRE Northumberland's Chairman David Montag-Smith is also chairman of the board of directors of Rathlin Energy Ltd who are exploring Yorkshire for shale gas.^[195]

Moratoria

In July 2014, the Scottish Government issued an Expert Scientific Panel Report on Unconventional Oil & Gas which investigated the technical, and environmental challenges of this technology.^[196] After the third reading of the Infrastructure bill in January 2015, Scotland imposed a moratorium, pending another environmental review. This prompted negative comment from the original report authors.^[197]

In October 2014, the European Academies Science Advisory Council issued an expert review of "the issues around fracking and the underlying science" following the EU Commission's January 2014 recommendations for "Minimum principles for the exploration and production of hydrocarbons (such as shale gas) using high volume hydraulic fracturing". The expert review stated: "This EASAC analysis provides no basis for a ban on shale gas exploration or extraction using hydraulic fracturing on scientific and technical grounds".^[198]

Public opinion

In September 2014, Nottingham University published a report on public attitudes, showing a slight reversal of the negative views that were held on hydraulic fracturing.^[199] A poll for the Guardian reported that 70% of people were against hydraulic fracturing in National Parks. When the caveat 'fracking with proper regulation' was applied support for hydraulic fracturing rose to 57%, with 26% opposed.^[200]

In May 2014, an ongoing survey by the University of Nottingham indicated that support for hydraulic fracturing fell below 50% for the first time. The publicity surrounding the Balcombe protest was considered an important factor.^[201]

A January 2014 Guardian poll found that a majority support shale gas extraction, but by a somewhat narrower margin than previously. To the question "Should shale gas extraction be allowed?" 53% said yes (down from 58% in July 2012), and 27% answered no (up from 19% in July 2012).^[202]

A poll conducted by Opinium/Observer in August 2013 showed that while men in the UK were evenly divided about fracking taking place in their area, women were strongly against it; the population as a whole preferred renewables such as wind farms.^[179]

An ICM poll in August 2013 found that public opinion in the UK was in favour of hydraulic fracturing in general, by 44% in favour to 30% opposed. However, when asked if they favoured hydraulic fracturing in their own area, the public split evenly, 40% in favour to 40% against. Support for fracking was stronger among men, older people, and conservatives.^[203]

See also

• Cost of electricity by source
• Oil and gas industry in the United Kingdom
• Refracktion, an environmental organisation

References

External links

• Environment Agency requirements for 'Non Hazardous' chemicals
• DECC's FAQs on shale gas
• British Geological Survey's information about shale gas
• BBC 2012, Fracking: Untangling fact from fiction
• Fluid proof drill pads video by Cuadrilla

UK Government Publications

• Planning Permission and Communities.
• 'Facts about Fracking'
• 'Climate Change'
• 'Design to Decommissioning'