УДК 504

ЭКОЛОГИЧЕСКИЕ И ПОЛИТИЧЕСКИЕ АСПЕКТЫ ДОБЫЧИ СЛАНЦЕВОГО ГАЗА НА ПРИМЕРЕ ВЕЛИКОБРИТАНИИ

Сулейменова Алуа Бахытовна
Эдинбургский университет (Эдинбург, Великобритания)
Выпускник Эдинбургского университета (2013), специалист в области экологии и охраны окружающей среды. Научные интересы: биогеохимия, экологическое моделирование, ГИС, устойчивое развитие

Аннотация
Данная статья посвящена обзору экологических и законодательных аспектов, связанных с добычей сланцевого газа в Великобритании. Проведенный обзор позволяет утверждать, что разработка сланцевых месторождений может привести к серьезным рискам в области окружающей среды, которые должны быть рассчитаны и отражены в соответствующем экологическом законодательстве.

ENVIRONMENTAL AND POLITICAL IMPACT OF SHALE GAS DEVELOPMENT IN THE UK

Suleimenova Alua Bakhytovna
University of Edinburgh (Edinburgh, UK)
Graduate of the University of Edinburgh, UK, ecologist and environmental scientist. Scientific interests: biogeochemistry, ecological modelling, GIS, sustainable development

Abstract
This article provides an overview of environmental and legal aspects related to the extraction of shale gas in the UK. The review suggests that alongside economic opportunities, shale gas production may also bring environmental risks and uncertainties which need to be addressed by appropriate ecological regulation before shale gas exploration goes any further ahead.

Keywords: ecological legislation, ecological risks, hydraulic fracturing, shale gas, unconventional energy sources


Рубрика: 04.00.00 ГЕОЛОГО-МИНЕРАЛОГИЧЕСКИЕ НАУКИ, 05.00.00 ТЕХНИЧЕСКИЕ НАУКИ, 25.00.00 НАУКИ О ЗЕМЛЕ

Библиографическая ссылка на статью:
Сулейменова А.Б. Environmental and political impact of shale gas development in the UK // Современные научные исследования и инновации. 2013. № 9 [Электронный ресурс]. URL: http://web.snauka.ru/issues/2013/09/26376 (дата обращения: 01.10.2017).

Recent advances in gas extraction technologies have allowed affordable access to previously inaccessible shale gas deposits, leading to an increase in domestic energy production and significant energy independence in the US and elsewhere. Preliminary estimates conducted by the British Geological Survey suggest that by analogy with similar producing shale wells in the US, the UK shale gas reserves could produce enough energy to meet its gas consumption for two years. However, the UK shale gas industry is still in early stages of development and the amount of its total, onshore and offshore, shale gas reserves is very much open to debate. Current research in this area suggests that alongside economic opportunities, shale gas production may also bring environmental risks and uncertainties which need to be addressed by appropriate regulation before shale gas exploration goes any further ahead.

WHAT IS SHALE GAS?

The increasing global demand for energy, coupled with gradual depletion and unequal distribution of fossil fuel resources have encouraged research and investments in more advanced technologies to extract formerly inaccessible or uneconomic depth hydrocarbons, such as shale gas, shale oil, tight gas, and coalbed methane.1 Due to the unique nature of geological formations in which they are trapped, these resources are called “unconventional”, as opposed to “conventional” oil and gas found in  sandstone or limestone reservoirs. One of the most rapidly developing unconventional energy resources is shale gas, which is predominantly methane with smaller amounts of other light hydrocarbons, carbon dioxide, oxygen, nitrogen, hydrogen sulphide, and trace gases [1]. It resides in a fine-grained sedimentary rock known as shale, at a depth of more than 1 km. The amount of gas stored within shale is variable depending on rock quality, i.e. the total pore space, the amount of organic matter present and the maximum temperature and pressure the rock has experienced [2].In order to extract shale gas, the characteristics of the reservoir need to be altered using hydraulic fracturing (“fracking”) coupled with horizontal drilling [3]. This process involves pumping a water-based fluid mixed with proppant (which is typically quartz sand or some other granular material) into a well at high pressure to fracture the surrounding rock formation and create pathways for the flow of gas into the production well [3].

The world’s largest shale gas reserves are deposited in China, USA and Argentina[4]. The UK possesses about 150 billion cubic meters of shale gas which is low by world standards (e.g. 200 times less than in China) but sufficient to meet the UK’s gas consumption for two years [5]. These estimates are referred to as onshore reserves only, whereas offshore deposits could be 10 times more abundant [6]. Although none of the shale gas wells drilled has been production tested, interest in exploration for shale gas in the UK is steadily increasing, as the North Sea reserves are gradually depleting and the UK becoming a net energy importer [7]. Its largest concentration of shale gas lies in the Edale and Widmerpool Gulf in the Midlands, in West Lancashire, Cheshire, Wales and South West England [8]. However, there are also some risks and challenges associated with shale gas extraction. Thus, Cuadrilla Resources, a UK energy company playing a leading role in shale gas industry, suspended test drilling in the Bowland basin in Lancashire following minor tremors induced by the high pressure fracking technology [9]. Similarly, concerns about induced seismicity have led to moratoria on hydraulic fracturing in some parts of the USA, Canada, France, South Africa and Bulgaria [10]. Other sources of potential risk include groundwater contamination, water sourcing and disposal, and land take. In addition, shale gas development may have political impact through influencing UK’s energy markets and energy security [8]. Understanding these challenges is key to developing effective policies to appropriately address sustainable extraction and use of shale gas in the UK. 

ENVIRONMNETAL RISKS FROM SHALE GAS DEVELOPMENT 

Shale gas extraction in the UK is still in its early stage and involves only exploratory activities [8].However, in order to determine its feasibility in the UK’s geologic and environmental settings and decrease the footprint of its nationwide production, special attention needs to be paid to the scale of potential risks associated with shale gas extraction and use.

Induced seismicity. Natural seismicity in the UK is low by world standards and is likely to be less than 5 ML on the Richter scale [9]. It is predicted that hydraulic fracturing and well-completion operations in the UK may cause minor earthquakes and tremors of 4 ML which is sufficiently low to cause significant surface damage [9]. Thus, the largest earthquake triggered by hydraulic fracturing in Lancashire had a magnitude of only 2.3 ML and was associated with the transmission of injected fracture fluid to a pre-stressed tectonic fault causing it to reactivate and release energy [10]. However, the use of underground explosives to conduct seismic testing resulted in strong opposition of local public and exploratory drilling in Lancashire was voluntarily suspended by the gas operator [11]. Future seismic events in the UK can be managed by adopting more cautious operating procedures and conducting seismic reflection surveys to identify and map existing faults and characterise stresses [11]. In addition, to ensure a prompt response, it is recommended to use traffic light control systems to perform real-time seismic monitoring and reporting [9].

Groundwater contamination. Concerns have been raised about the possible groundwater contamination by methane and chemical additives used in the process of hydraulic fracturing [10]. Chemical additives may include acids, surfactants, biocides, gel and foaming agents, scale inhibitors (e.g. strontium and barrium) and pH stabilizers. Although these components contribute less than 1% to the total volume of the fracturing fluid, many of them are carcinogenic and neurotoxic [4]. Little is known about the potential risks associated with the use of these substances, and therefore, to adopt appropriate precautious measures to development of hydraulic fracturing, more evidence-based research is needed [13]. However, there have been recorded some instances of methane contamination of shallow aquifer systems overlying large shale formations in the Marcellus and Utica in north-western Pennsylvania [14]. It is suggested that hydraulic fracturing increases connectivity in fractured rock aquifers and enables methane to migrate upward. Similarly, methane can flow laterally and vertically through fracture systems and eventually escape into aquifers due to improperly cased shale-gas wells. Thus, to avoid methane leakage, it is important to ensure the integrity of wells and other equipment throughout the whole life-time of the well pad [14]. Due to different geology, the UK is thought to have lower risk of groundwater contamination, since most of its drinking-water aquifers lay above the level at which hydraulic fracturing usually takes place. In fact, if there is at least 600 meters separation between the groundwater source and the gas producing zone, the likelihood of fracturing fluid reaching drinking water supplies is remote [9]. However, where the separation distance is not as large, the risks of groundwater contamination due to shale gas extraction are considered “moderate” to “high” [9]. To characterise long term effects of hydraulic fracturing fluid, the British Geological Survey is currently carrying out baseline studies of methane concentrations in groundwater for future comparative analyses after any hydraulic fracturing operations [15].

Water sourcing and disposal. Depending on the depth and permeability of shale formation, hydraulic fracturing requires on average from 7.7 to 38 megalitres of water [16]. To minimise haulage costs, this water is usually extracted on-site from adjacent streams and groundwater sources. Thus, in the US, 70% of water is withdrawn from surface waters and 30% is provided by public water suppliers. In addition, most of the water used in hydraulic fracturing (25-100%) cannot be recovered and re-used [17]. As a result, large-scale water abstraction may lead to changes in local water regime, including sedimentation and erosion [9]. For instance, there have been some concerns regarding high volume withdrawals from nearby watersheds in the Marcellus Shale region in Pennsylvania USA, causing reduced aquifer levels coupled with altered salinity, enhanced bacterial growth, and destabilisation of local geology [18]. In the UK, water abstraction is regulated by the Water Resources Act 1999 which requires gas operators to obtain a special abstraction permit from the environmental regulator if more than 20,000 litres need to be withdrawn per day [9]. This is particularly an issue if a single catchment is used by multiple well pads which cumulatively impose a “moderate” to “high” risk to local hydrological resources. Thus, water use should be minimised where possible through wastewater recycling and reusing [18]. In addition, in some US shale gas reserves, water is abstracted from deep and more abundant saline aquifers rather than from more susceptible freshwater sources, or is simply replaced by waterless fracturing fluids, such as carbon dioxide and nitrogen gas foams and gels [18]. The use of these liquids may also decrease the wastewater toxicity since they do not dissolve radioactive material, heavy metals and some other water-soluble chemicals.

Land take. It is estimated that hydraulic fracturing requires twice as much land as conventional drilling and, hence, to produce a similar gas yield as one conventional gas well in the North Sea, about fifty shale-gas wells would be needed [9]. Overall, Europe may require up to 1.4% of the land above a productive shale gas well to achieve its full exploitation capacity, which is just three times less than the total land in Europe currently occupied by housing, industry and transportation [9]. The most land-demanding stage of the shale gas extraction is wellsite preparation which involves construction of well pads and associated infrastructure, such as pipelines, water impoundments, gravel access roads and utility corridors [18]. It may not always be possible to fully restore a site in areas of high agricultural or natural value following a well completion or abandonment, especially over wider areas with multi-well pads. Large-scale disturbance may cause long-term environmental impacts, leading to habitat fragmentation and biodiversity loss [9]. Thus, Marcellus shale gas wells in Pennsylvania require nearly 3.6 ha of land per well pad with an additional 8.5 ha of indirect edge effect [19]. It is estimated that further development of shale gas resources across the Allegheny Plateau in Pennsylvania will affect up to 1072 ha of agricultural land and 894 ha of forest land imposing pressure on remaining farmlands and causing regional forest fragmentation [20]. In addition, the loss of core forest increases a risk of water pollution in headwater streams, bringing not only land use problems, but also a significant water management challenge [19].

Based on American experience, it is expected that land managers in the UK will face similar consequences from shale gas development. However, given the UK’s size and high population density, it is likely that its shale gas production will face even stronger public opposition and environmental lobby against drilling and fracking, than the US [21]. 

ECONOMIC OPPORTUNITIES AND POLICY IMPLICATIONS OF SHALE GAS DEVELOPMENT 

Shale gas currently accounts for nearly 23% of marketed gas in the USA, transforming US economy and leading to its significant energy independence [22]. Moreover, by 2021 the US is expected to become a net global exporter of natural gas with the potential to replace more carbon-intensive oil and coal resourcesand cutthe US carbon emissions by 450 million tonnes [7]. The UK is expected to be only half as successful as the US due to smaller shale gas deposits, harder extraction from deep shale rocks and the absence of shale-gas-specific regulation [7]. In addition, there can be some challenges with interpreting and implementing regulation mechanisms at both the European and the UK level [23]. Nevertheless, the potential for development is high and shale gas may offer a viable alternative to renewable energy sources.

Energy security. Over the last 10 years, natural gas production in the North Sea fell by nearly 40% and is expected to experience a further decline by 43% in the next 20 years [8]. In addition, the generation capacity of the UK’s coal and nuclear sources will decrease by almost 20% in the next decade. Although the deployment of renewables could potentially replace this lost capacity, in reality it will take longer to reach scale rapidly enough [7]. In addition, despite increasing renewable subsidies (which totalled to £1.1 billion in 2010), the UK failed to meet its 10% renewable electricity target, producing only 6.5% in 2010. As a consequence, it is doubtful whether the UK would reach the EU Renewable Energy Directive target of 30% by 2020 [24]. That is why putting an emphasis on the development of shale gas which proved to be commercially viable in North America, may help to diversify energy supply sources moving away from the projected dependence on imports [7]. Preliminary calculations based on the analogy with similar producing shale wells in the US, showed intensive development of shale gas in the UK may provide 8% of 2011 gas supply in the next 10 years which is sufficient to offset 60% of the expected decline in the UK’s conventional natural gas production [7]. With respect to the US experience, an additional 8% would help to reduce gas prices and minimise the proportion of households in fuel poverty. In addition, shale gas industry can influence the economy and create 35,000 extra jobs [7]. Although UK’s shale gas is unlikely to replace coal and conventional oil in the near future, it could still improve the security of supply from a domestic energy resource and contribute to emission cuts and decarbonisation.

Policy implications. Currently, there is no regulatory framework in the UK specific to shale gas exploration and extraction [25]. As a result, shale gas development falls under the generic category of the onshore and offshore oil and gas legislation. This may result in regulatory uncertainties and legal gaps which could potentially slow down shale gas development [23]. Thus, shale gas is currently owned by the State, since land ownership in the UK does not apply to hydrocarbons below the surface. As a result, land owners cannot directly benefit from shale gas development, whereas in the US the rights to natural gas are held in private ownership and therefore land owners would be paid a royalty based on their land share. This is often considered to be one of the reasons for the ready acceptance of shale exploration in the US [26]. Introducing similar financial compensation to local communities in the UK may improve public opinion and enhance lobbying activities in favour of shale gas development [21].

Another limitation in the current regulatory framework is the fact that shale gas exploration in the UK is regulated by multiple authorities, i.e. the Department of Energy and Climate Change, the Mineral Planning Authority, the Environmental Agency, the Health and Safety Executive, and the Health Protection Agency, which are responsible for reviewing the operator’s plans for the design, preparation and maintenance of a gas well and granting a license or a permit for the site to begin operation [23]. In case the license for shale exploration is issued, the operator has to go through a similar planning and permit process to obtain a new license for shale gas production. Due to such a generic regulatory approach, the whole process of shale gas development is significantly slowed down [23]. However, despite this detailed, multi-staged permit process, authorization of shale drilling may not necessarily require an Environmental Impact Assessment (EIA) prior to well preparation. For example, since the drilling operations in the Bowland basin in Lancashire were considered “exploratory” as opposed to “commercial”, no EIA was conducted on the site, despite significant environmental impact associated with shale gas extraction [13].Similarly, due to poor understanding of the carbon footprint of shale gas, current legislation does not consider the role of carbon capture and storage for shale gas fired power stations and fails to address the issues of gas venting and flaring [10]. Finally, it is still not clear how shale gas will fit into the UK’s energy mix and the government’s energy plans which have been focussing on renewable sources [13]. Nevertheless, the UK is likely to incentivise its shale gas exploration while keeping the balance in other low-carbon technologies and mitigating disincentives to invest in renewables [5].

CONCLUSIONS AND FUTURE DIRECTIONS

Although the UK is unlikely to emulate the US success and experience a shale gas revolution, shale gas may well contribute to its energy market and diversify its gas supply, reducing levels of fuel poverty and dependence on imported energy sources. Due to local geologic settings, hydraulic fracturing in the UK is expected to be harder than in the US, but environmental impacts are likely to be less significant. Thus, naturally low seismicity and shallow drinking water systems would not probably result in damaging tremors and groundwater contamination. However, water issues associated with water abstraction and wastewater disposal coupled with land disturbance and habitat fragmentation may raise serious concerns among land and environmental groups, leading to strong lobbying against shale gas exploration. These issues need to be addressed by adopting precautious measures when planning a well pad construction and developing a new regulatory framework sufficient for licensing and monitoring commercially viable production sites on a national level. A particular emphasis should be put on a thorough Life Cycle Analysis and an Environmental Impact Assessment which are intended to identify all the potential risks of the shale gas project in the early stages of planning.

Using the US experience as a benchmark, it is possible to predict that in the next 10 years shale gas in the UK will account for nearly 10% of its gas consumption and will help to fill the gap left through depleting oil and gas reserves in the North Sea. In addition, shale gas could bring £95 billion of investment and create new marketing opportunities for business development.

Overall, developing UK shale does not solve all the current energy problems and cannot be considered a silver bullet, but it could make a large contribution to the UK energy markets, enabling the transition to a low carbon economy.


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