Fracking in the United Kingdom

Although hydraulic fracturing in the United Kingdom has been common in North Sea oil and gas fields since the late 1970s, and has been used in about 200 British onshore oil and gas wells since the early 1980s, the technique did not attract public attention until its use was proposed for onshore shale gas wells in 2007.

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

The European Union has also issued an approval for fracking under certain conditions from January 2014. 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 USA.

The process was suspended in the UK between June 2011 and April 2012 after triggering minor earthquakes, but a report into the incidents concluded that earthquake risk was minimal, and recommended the process be given nationwide clearance.

File:Cuadrilla Resources Frack job at Preese Hall No.1 well.jpg

Cuadrilla Resources Frack job at Preese Hall No.1 well

File:Preese Hall No1 well in Lancashire. UK.jpg

Preese Hall 1 well location Cuadrilla Resources

Background

The surge of public interest in shale hydraulic fracuring in the UK can be traced to 2007, when Cuadrilla Resources was granted a licence for shale gas exploration along the coast of Lancashire. Cuadrilla has American-Australian-British ownership, though close ties have developed between China National Offshore Oil Corporation (CNOOC) and one of Cuadrilla's backers. The company's first and only hydraulic fracturing job to date was performed in March 2011 near Blackpool.

Other companies, including Eden Energy, UK Methane Ltd, Coastal Oil and Gas, Celtique Energie, and IGas Energy, have since obtained exploration licences, with test drilling being carried out in Somerset, Glamorgan, Cheshire and other locations.

History

The first experimental use of hydraulic fracturing was in 1947, and the first commercially successful applications of hydraulic fracturing were in 1949. Worldwide, as of 2012, 2.5 million hydraulic fracturing jobs have been performed on oil and gas wells. High volume, or massive fracturing involves techniques used to release oil and gas from low-permeability rocks, and is defined as a procedure involving more than 100,000 US gallons of water. Massive hydraulic fracturing (MHV)was first used in thousands of gas wells in the western United States in the early 1970s. Massive hydraulic fracturing spread in the late 1970s to western Canada, Rotliegend and Carboniferous gas-bearing sandstones in Germany, Netherlands onshore and offshore gas fields, and the United Kingdom sector of the North Sea. This industry review of the technology shows on page 3 that the first MHV job in shale was completed in 1977, and the technique became commercially viable in 1998. This lead to the shale gas boom starting from 2000 on.

Areas with shale gas potential

Main article: Shale gas in the United Kingdom

The main areas identified by the Department of Energy and Climate Change run from just south of Middlesbrough in a crescent through East Yorkshire, Lincolnshire, Northamptonshire, Buckinghamshire and the Cotswolds to Somerset and Wiltshire. It then turns along the South Coast and Downs, including most of Dorset. Shale gas sites are under investigation in Sussex; the Mendip Hills, south of Bath; Kent; Lincolnshire; South Wales; Staffordshire; Cheshire, and more sites near the existing find in Lancashire.

File:Ohio Uttica Shale Gas Well.pdf

Ohio Uttica Shale Gas Well

From 2014, more land is to be offered for licence to explore. This vastly increases the area that could be utilised.

Shale oil potential in the Weald Basin

Oil well in Lincolnshire. Many such as this have been hydraulically fractured with no environmental issues

A BGS/DECC report from May 2014 indicates that there is little potential for shale gas fracturing in the Weald Basin, south of London. It does suggest that there is the possibility for the extraction of light tight oil from shales (LTO) and the figure of 4.4 billion barrels is suggested. (Range 2.2 billion to 8.6 Billion). The data is said to have a high degree of uncertainty, and the amount that could be produced is unknown, and could be zero. This would need test drilling to establish the producibility of that oil, and its economic viability.

The Weald basin has been noted as having hydrocarbon bearing rocks from Roman times, and the first well was drilled in 1895. To date 117 exploration wells, 31 appraisal wells, and 100 development wells have been drilled. Thirteen fields are in production.

Shale oil, or LTO has oil already in place, but it will need hydraulic fracturing and horizontal drilling to extract, due to the very low permeability. An example of this is the Bakken formation in North Dakota. Others are the Barnett Shale and Eagle Ford Shale, in the USA, with others in Australia, Oman, Siberia, Mexico, and Argentina. Oil shale is not directly producible, unless it is mined, and needs to be heated underground or on the surface to extract hydrocarbons. There are serious environmental concerns with this process.

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.

The Liberal Democrats, in 2013 in a coalition government with the Conservative government which strongly supported fracking, 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. 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. By contrast, UKIP is enthusiastic about shale gas, a stance that is partly derived from its hostility to wind farms.

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. Green Party leader Natalie Bennett said of the government's proposal to turn the business taxes gained from fracking 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,”

The government is considering a change in the law to allow companies to carry out hydraulic fracturing under houses. At present homeowners could prevent this using trespass laws. In May 2014, this matter was put out for consulation.

Effect on House Prices

The possible effect of house prices due to fracking is one that will always get the attention of residents. House prices can be researched on or . As of August 2014 there is no reported reduction in the Blackpool area, where Cuadrilla are proposing to frack 4 wells.

In August 2014, a report called 'Shale Gas:Rural Economic Impacts' was published by the UK Government, having been written in March 2014. It was notable as large parts of this have been redacted, leading to criticism about the transparency of information being provided.. In certain areas of the USA house prices have reduced in areas where fracking is taking place, and whether this will affect the market in the UK remains to be seen.

House insurance

With the high value of UK houses, the ability to insure a house is important. It has been widely reported that fracking will make a house uninsurable . The links shows that this is not the current situation with one of the companies mentioned. Earthquake risk is covered as standard in UK buildings insurance, along with fire, smoke, explosion, lightning or earthquake as can be seen on this document.

Environmental issues

Frac job in process. Many trucks will provide the power to break rocks deep underground. This process could take a week.

Gas wells after the drilling rig and other equipment has been removed.jpg

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

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 fracturing. 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?'.

Climate Change

Shale gas is largely methane, a hydrocarbon fuel. As such the carbon dioxide it produces may contribute to global warming, although less so than coal. Of more concern is leaking or fugitive emissions of unburned methane, which is a greenhouse gas. It has been argued that, in opening a new source of hydrocarbons, it may reduce the incentive and financing of renewable sources of energy.

There is evidence that the intermittent nature of renewables means that some other form of energy is needed to fill the gap. The Texas Clean Energy Coalition reported in June 2013 that there is a strong complimentary relationship between natural gas and renewables. Not only may increasing concerns about air pollution and associated health and environmental consequences create additional costs for coal fired generation, but gas fired generation also matches much better with intermittent renewable generation from solar and wind projects than do coal fired power plants. The path to low carbon generation in Texas will therefore likely require the co-development and integration of both gas and renewable resources.

In April 2014, the IPCC (Intergovernmental Panel on Climate Change) issued its 5th Assessment report. With regard to natural gas, and the shale gas debate, it states GHG emissions from energy supply can be reduced significantly by replacing current world average coal‐fired power plants with modern, highly efficient natural gas combined‐cycle power plants or combined heat and power plants, provided that natural gas is available and the fugitive emissions associated with extraction and supply are low or mitigated (robust evidence, high agreement). In mitigation scenarios reaching about 450 ppm CO2eq concentrations by 2100, natural gas power generation without CCS acts as a bridge technology, with deployment increasing before peaking and falling to below current levels by 2050 and declining further in the second half of the century (robust evidence, high agreement).

Currently, the UK generates 31% of its electricity from coal,. Background to the current UK energy mix can be seen on this link.

Water contamination

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.

Water UK have signed a memorandum of understanding based upon a briefing paper by Water UK.

The British Geological Survey, in reviewing the US experience with hydraulic fracturing of shale formations, observed: where the problems are genuinely attributable to shale gas operations, the problem is with poor well design and construction, rather than anything distinctive to shale gas.

The DECC reported that it had approved the use of three chemical additives in hydraulic fracturing slurries by Cuadrilla: polyacrylamide (friction reducer); hydrochloric acid, which is used at concentrations of under 1% at which concentration it is considered non-toxic; and a non-toxic biocide. In its one hydraulic fracturing job to date, Cuadrilla used only non-toxic polyacrylamide, at a concentration of 0.05%. The Environment Agency will only issue permits for what it considers non hazardous chemicals (See Regulatory Issues below).

One potential pollution path is from leaks on the surface through spillage. The EA require chemical and fluid proof drill pads. This is shown on this video, from Cuadrilla.

Flowback Fluid

Some flowback fluid can be treated and reused as fracking fluid. It can contain high levels of salt, and low levels of radioactive materials, known as NORMS (Naturally Occurring Radioactive Materials). The disposal and treatment of these fluids must be done under a licence from Environment Agency. Regulations regarding radioactive material and other contaminants have been tightened. Fluid disposal wells are not currently licensed in the UK by the Environment Agency. Disposal wells have been shown to be the main cause of significant earthquake risk in certain areas.

Licences were withdrawn by Cuadrilla when arrangements for disposal and treatment of contaminated water were not considered to be adequate by the Environment Agency. Waste water treatment companies have devised methods of removing 90% of NORMS allowing safe disposal of fluids under Environment Agency licence. These techniques can reduce radioactive content to less than some bottled waters.

CIWEM (The Chartered Institute of Water and Environmental Management) published a review in January 2014. It recommends shale gas extraction will be low risk as long as it is properly managed. Contamination of aquifers from mobilisation of solutes and methane is unlikely where shale plays exist at depth in the UK. The British Geological Survey believes such contamination is unlikely to occur if shale gas exploitation is restricted to depths greater than 1500m, and Contamination of soil, surface or groundwater from spills of returned waters is a considerable hazard. Risk assessments need to consider all potential sources of pollution, potential pathways and receptors.

Water Depletion

There are concerns about water supplies in certain areas.

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.

Water tanks preparing for a frac job. These are compulsory under UK and EU regulations. Open pits, which can flood or split have been the source of many pollution incidents in the USA

The Chartered Institution of Water and Environment Management have published a policy document on various water and flowback fluid issues.

DEFRA data indicates the amount of water abstracted nationally, at around 16 billion cubic metres. The DECC report shows the usage expected for fracking a well. It is equivalent to watering a golf course for a month. A 2011 report from the Tyndall Centre estimates that to support a 9 billion bcm/year industry, between 1.25 to 1.65 million cubic metres would be needed annually, which amounts to 0.01% of the total water abstraction nationally. This does not mean however that there could not be shortages locally at certain times.

Some living in drier areas, in East Kent, for example, are concerned about the effect of fracking in using large volumes of scarce water supplies. East Kent falls within the Environment Agency's Southern Region, the third driest region of England and Wales, where "water is a scarce and often over-committed resource".

Earthquake risk

This link is the DECC statement on earthquake risk.(February 2014)

Cuadrilla voluntarily suspended hydraulic fracturing in June 2011, after fracking a well caused two small earthquakes in Lancashire, one of magnitude M 2.3.

The ReFINE consortium have produced a presentation on the seismic risks of fracking

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

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 fracking fluid below ground.

A 2012 report on hydraulic fracturing 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." Researchers at Durham University noted that earthquakes triggered by hydraulic fracturing are only rarely greater than M 1. There are only three known cases of hydraulic fracturing-induced quakes strong enough to be felt by humans at the surface: one each in British Columbia, Canada; Oklahoma, USA; and Lancashire.

Mentioned on Flowback Fluid above, seismic events with the potential to initiate damage (up to M 5.6) have been associated with a small number of fluid disposal wells in the USA.

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 fracking fluid is essential to minimise the risks to the environment and health

Aquifer contamination

From Frack Fluids

In the US the Environmental Protection Agency is doing a major study about this aspect of fracking. The report is due out in late 2014, and here is the interim report.

The ReFINE consortium have produced a video relating to the risks of aquifer contamination through fractures.

There have been concerns raised about the potential for fractures to penetrate aquifers, polluting water supplies. Research into hydraulic fracture growth in the US indicates that:

• induced fractures in sedimentary rock only rarely penetrate upward more than a few hundred meters,
• in layered sequences of sedimentary rocks, induced fractures tend to propagate laterally within a more brittle rock unit, rather than vertically across the different layers,
• induced fractures have a predominant vertical orientation when deep, and horizontal when shallow,
• fracture growth can be monitored in real time, using tilt meters and microseismogram recordings, and can be largely confined to the target formation.
• fractures do occasionally intersect faults, but data from many wells shows that vertical growth is also limited when this occurs.
• vertical propagation of a hydraulic fracture across layers is very inefficient and it is difficult to obtain extensive vertical growth.

Examining the maximum potential vertical growth of fractures, This paper 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.

The Royal Society report indicates on pages 31 to 37 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 concludes in 4.3.3. 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.

For deep formation water to pollute an aquifer it must first have a pathway to follow, and also have a driving mechanism to force it upwards. The fractures could possibly provide a pathway, but to rise the water would have to be buoyant. Oil in the UK, with a density less than 1 g/cc needs to be pumped out. Any formation water will usually have salts, heavy metals, and small amounts of radioactive materials dissolved in it. This means that its density will be greater than 1 g/cc, and as such there is no driving mechanism to pollute an aquifer, even if a pathway existed, as the water cannot rise.

Methane, and Gasland

There is also concern about the potential for methane contamination of aquifers. The BGS have released national baseline methane levels, that range from negligible to high. Methane is not toxic but it does carry the risk of explosion in confined spaces, and is produced in the human gut. It is removable by the water companies by aeration, but that would be an expensive option. In the USA, baseline methane measurements were not made at the start of the shale gas boom, meaning that it is difficult to prove whether a gas problem is due to drilling, and leaking wells, or is naturally occurring. This practice is now changing as this baseline study shows.

Methane and the 'burning tap' from the Gasland film, by Josh Fox, has created a powerful public image. In this response from the Colorado Oil and Gas Conservation Commission attention is drawn to the difference between biogenic gas and thermogenic gas. Biogenic gas occurs in shallow formations and is associated with decomposition of biological material, and is largely methane. Thermogenic gas is formed deep in the earth, from biological material that has been heated. It contains a larger range of hydrocarbons. The tap in question produces water from a shallow depth through 4 coal seams, and is in an area that historically has been recognised as having a high level of biogenic gas. However, incomplete sealing of surface casing with cement could still exacerbate an already methane rich aquifer, hence the importance of baseline monitoring.

In 'Gasland Part 2', a follow up film to Gasland, the burning water hose scene was shown to be fake in the following legal judgement. The correspondence referred to in the film is available here. It shows the details of the steps taken after residents complained about gas in their water.

The issue of pre-existing methane is hotly debated. A study from Duke University is often quoted and this concludes that there is a link between methane gas in groundwater, and the proximity of gas wells, in 141 readings. However this larger study (1701 readings) in the same area has shown that methane gas concentration is independent of proximity to gas wells. There are several other studies that have been done that do not show correlation between fracked shale gas wells and methane or other contamination. Baseline studies also indicate that many wells are polluted with various contaminants, independent of fracking.

The exact pathway of pollution is complicated by the fact that in many areas in the USA, drilling has taken places since the 1860s, and Pennsylvania for example, has an estimated 300,000 abandoned wells, many of which have no records. These can provide leakage paths in rare circumstances.

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 commercial video explains the technique. This means that the engineers can modify the pump rate in shale gas fracking 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.

This video shows various aspects of fracking, including the traffic light monitoring, and microseismic array logging, and fluid disposal.

Use of Radioactive Sources

LI1LOG

One of the ways that definitive formation parameters can be measured is by well logging, such as the example displayed. This can be on wireline, or in a horizontal well, using logging while drilling. Measurement of formation density is made using a large sealed Caesium-137 source. This bombards the formation with high energy gamma rays. The attenuation of these gamma rays gives an accurate measure of formation density, and this has been a standard oilfield tool since 1965. Another source is Americium Berylium (Am-Be) neutron source used in evaluation of the porosity of the formation, and this has been used since 1950. In a drilling context, these sources are used by trained personnel, and radiation exposure of those personnel is monitored. Usage is covered by licenses from International Atomic Energy Agency (IAEA) guidelines, European Union protocols, and the Environment Agency. Licenses are required for access, transport, and use of radioactive sources. These sources are very large, and the potential for their use in a 'dirty bomb' means security issues are considered as important. There is no risk to the public, or to water supplies under normal usage. They are transported to a well site in shielded containers, which means exposure to the public is very low, much lower than the background radiation dose in one day.

There is often confusion between radiation exposure, and radiation contamination. Exposure would only involve the operators, and this is reduced by minimising the time the exposed source spends out of the transport container, or well. With regard to contamination, this would mean the source would have to leak or be breached. Sources are robustly built with no chance of radioactivity release under normal oilfield operations. The Cs-137 source is in a glass matrix and is doubly-encapsulated in steel. The tool is designed to withstand pressures of more than 25 Kpsi and 150 deg C. The reference also indicates that in the event of a logging tool becoming badly stuck in a well, the precautionary principle, if a 'fishing' operation were to be unsuccessful, would be to cement it in place, rather than to risk rupture.

Drilling issues

Well leak concerns

In March 2014, ReFINE (an independent research consortium led by Durham Energy Institute, one of eight Research Institutes at Durham University) published a report 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 September 2013 paper states True well integrity failure rates are two to three orders of magnitude lower than single barrier failure. 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.

The response from UKOOG 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 '50% of wells leak after some time and all wells leak eventually'. This is not an issue specific to fracking, it is a concern with every well that is drilled. This is based upon a work carried out by Schlumberger in 2003. The data is contained on a sales document that sells solutions to this problem to oil and gas companies. 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 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 integroty 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 the drilled well.

In this paper, data 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. The current regulations from the HSE are designed to mitigate these concerns, and seal wells back to the surface.

Concern has been raised about some wells drilled before the latest guidelines that do have potential leak paths. This reference 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.

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

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.

Sleeves for fracturing in stages.JPG 1.37 MB

Preese Hall # 1 well

In the Preese Hall 1 well, 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 frack 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 fracking. The borehole is fracked in stages, typically several hundred feet at a time, so if the casing is not well cemented, then the frack 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. A full report of the well is available here. This video describes the process of fracking

The role of pressure differential in a well during hydraulic fracturing is sometimes mischaracterized. When a well is fracked, or when any injection is carried out, this is done through a 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. 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.

Horizontal Drilling

One of the important developments which allows shale fracturing is the ability to deviate a well to follow a formation, using directional drilling technology, developed in the 1980s. Mud pulse telemetry, also known as logging while drilling means that the formation properties can be read in real time. The drill bit can then be steered, (geosteering) to stay within the target formation. This link also shows the ability of this to detect faults, and follow a target formation.

Regulation

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. 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 that outlined the requirements of the regulatory framework.

The House of Lords report into Fracking from the Economic Affairs Committee was published in May 2014. 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.

There are a variety of Government Agencies involved in regulation. (See external links below) The Department of Energy and Climate Change, DECC, is one of the key Departments to grant permission Applications will only be granted if the relevant agency is confident that there is no unacceptable impact to the environment and, in particular, to principal aquifers that provide potable water supply. As part of this process, operators are required to disclose the content of hydraulic fracturing fluids to the relevant environment agency.

Fracking fluids are required to be non hazardous, by the regulatory authority, the Environment Agency EA. In addition the link states that Operators should disclose, either on their own website or on third-party websites, the chemicals used in their fracturing fluid. 'Only substances that have been assessed as being non-hazardous within the specified situation can be used. There are other regulatory authorities in Scotland, Wales and Ireland

Another main player in the regulation of the industry 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. Under current regulation, the 'independent' Well Examiner can be an employee of the operating company, as identified in the RAE report recommendations chapter 3.

In the event of a poor cementation remediation must involve outside expert opinion from the Well Examiner. Poor cementation has been identified by the RAE report as one of the main pollution paths and sources of surface gas leaks in the USA. Concern has been expressed about cuts in jobs at the HSE that could lead to a non rigorous inspection regime.

The British Geological Survey (BGS) also have to be consulted.

Local Councils and parish councils also have some regulatory powers, with regard to planning permission. These can be overturned on appeal.

The Minerals Planning Authority (MPA) will determine if an environmental impact assessment (EIA) is required. This would be funded by the operating company, as can be seen here.

The regulatory process is clearly set out in the UKOOG flow chart here In addition this document details the various techniques and practices required, and this document indicates the expectations involved with community engagement. 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 stage'.

Public Health England concluded in October 2013 that, if properly regulated, hydraulic fracturing would pose minimal risk to public health. The government considers the current oil and gas regulatory system "robust", but is seeking ways to improve it.

A 2013 government-sponsored study of the effect of large-scale natural gas development in Britain concluded that it would not interfere with efforts to halt climate change.

Chemicals Permitted for Fracking in the UK

Only 'Non-Hazardous' chemicals are permitted for frac fluids in the UK by the Environment Agency, and the chemicals typically make up less than 1% of the total volume of the fracturing fluid. 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, subject to appropriate protection for commercially sensitivity Increasingly, food additive based chemicals are becoming available. Chemicals used in drilling and frack fluids are assessed case by case by the environmental regulator for hazards. The operator must prove any chemicals they want to use are not hazardous in that application

In the Preese Hall 1 well, the concentration was 0.05%. However, when millions of gallons of water are being used, the amount of chemicals per fracking operation could be large. For example, a four million gallon fracturing operation would use at 1%, 180 tonnes. At 0.05% this would be 9 tonnes. (2million gals = 1.8 x 10^7 kg = 1.8 x 10^4 tonnes. 1% = 180 tonnes, at 0.05% 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. Increasingly UV treatment will replace chemicals for treatment.

Although some of the chemicals used in fracking fluids such as hydrochloric acid may be classified as toxic, corrosive or irritant, they are non-toxic at the concentrations used.

Geothermal Energy

Circulation of water to extract heat energy is a potential source of reliable energy, and to enable the flow of fluids in deep rocks, hydraulic fracturing would be required. From the 'Underground Drilling Access' consultation paper, Deep geothermal energy is renewable and low carbon. It is a particularly attractive renewable technology because geothermal plants have little visual, noise or air quality impact, aside from the initial drilling. And, unlike renewable technologies such as wind, hydro and solar that are affected by changes in the weather, geothermal plants can run almost continuously. For power plants, this would provide baseload electricity. For heat, this would provide a reliable source all year round. (Page10)

Opposition

Balcombe anti-fracking protest - July 2013

There are a number of anti-fracking groups, 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, Ribble Estuary Against Fracking, NO Fracking in Sussex, Frack Free Fernhurst and The Vale Says No!

The Environmental Group Greenpeace publish an online 'live' fracking report

Friends of the Earth are also against Fracking.

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.

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 fracking could contaminate Bath's famous hot springs. Similar worries about future fracking have been aired in a number of other places, including the Vale of Glamorgan and Woodnesborough, Kent. Industry assurances about its forthcoming plans were tarnished in January 2012, though, when Cuadrilla Resources came under fire for its categorical denials of plans to frack near Balcombe after documents from parent company AJ Lucas materialised appearing to indicate the complete opposite.

In March 2014, a group of conservation charities including the RSPB and the National Trust released a report containing a 10-point plan for increased regulation, and highlighting concerns about groundwater pollution, industrialization of the countryside, Environmental Impact Assessments, and fracking inside National Parks. The response from UKOOG, the representative body for the UK onshore oil and gas industry 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. Residents feared that successful exploration would be the prelude for fracking. 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. 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 fracking. 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 fracking for extraction.

Coastal Oil and Gas decided to appeal to the Welsh Government, rather than undertake legal action against the local authority, and a public enquiry began in May 2012. 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, and were increased to near certainty after Welsh Water effectively retracted its previous risk assessment.

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; 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. The company also relies heavily on industry analysis of a European Climate Foundation report, though the analysis is rejected by the ECF itself. 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."

Public opinion

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.

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.

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).

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

See also

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

External links

• Industry guide to regulation process
• Environment Agency requirements for 'Non Hazardous' chemicals
• Guide to the regulation of a well by the Health and Safety Executive
• Illustration of fracking
• DECC's FAQs on shale gas
• British Geological Survey's information about shale gas
• Guardian coverage of shale gas and fracking
• Cuadrilla Resources
• BBC, Fracking: Untangling fact from fiction

UK Government Publications

• Planning Permission and Communities.
• 'Water'
• 'Facts about Fracking'
• 'Climate Change'
• 'AirQuality'
• 'Regulation'
• 'Design to Decommissioning'
• 'Earthquake risk'