Unconventional Hydrocarbon Extraction Research Articles

An introduction to the Bowland Shale Formation, UK: processes and resources

Abstract This volume showcases recent geological, geophysical and geochemical research on the Carboniferous Bowland Shale Formation. The Bowland Shale is a relatively thick and extensive Palaeozoic black shale unit with a long history of debate and controversy in the UK. The Bowland Shale is proven in many of the key Carboniferous basins in the Midlands, northern England and North Wales, and represents a significant, near-continuous temporal record spanning 16 Myr including the important mid-Carboniferous boundary (Mississippian–Pennsylvanian). Since the first geological surveys in the late nineteenth century, the Bowland Shale has been of interest for a variety of reasons, including the search for Irish-type Pb–Zn base metal mineral deposits, and as a source rock in conventional hydrocarbon systems. In the mid-2000s, attention turned to the Bowland Shale as a target for unconventional hydrocarbon extraction, shale gas, following success in the USA. This placed the Bowland Shale at the centre of a series of interconnected controversies and debates from the local to national scale. The geological credibility of the purported shale gas resource in the UK was – and continues to be – highly contentious. This volume contributes to a more updated view of the Bowland Shale, covering topics such as sedimentary, geochemical and physical properties and processes, basin-forming events, hydrocarbon prospectivity, mineralization and heat and fluid flow in the subsurface. The volume also includes a field guide to some of the key localities in the UK. With the benefit of hindsight offered by the latest generation of research, the early regional shale gas assessments failed to attach sufficient weight to the compositional heterogeneity, structural complexity, compartmentalization and highly variable exhumation, erosion and palaeo-heat flow history of the Bowland Shale. The following topics are identified as promising avenues for future research beyond shale gas: (1) the role of the Bowland Shale in the context of mineral systems; (2) the role of the Bowland Shale as a cap rock in the Lower Carboniferous limestone geothermal play and potentially as an analogue of CO 2 or radioactive waste storage in the UK; and (3) pathways and mechanisms for weathering, alteration and trace element release from the Bowland Shale into the surface and/or subsurface environment.

Social Vulnerability and Groundwater Vulnerability to Contamination From Unconventional Hydrocarbon Extraction in the Appalachian Basin.

Unconventional oil and gas (UOG) development, made possible by horizontal drilling and high-volume hydraulic fracturing, has been fraught with controversy since the industry's rapid expansion in the early 2000's. Concerns about environmental contamination and public health risks persist in many rural communities that depend on groundwater resources for drinking and other daily needs. Spatial disparities in UOG risks can pose distributive environmental injustice if such risks are disproportionately borne by marginalized communities. In this paper, we analyzed groundwater vulnerability to contamination from UOG as a physically based measure of risk in conjunction with census tract level sociodemographic characteristics describing social vulnerability in the northern Appalachian Basin. We found significant associations between elevated groundwater vulnerability and lower population density, consistent with UOG development occurring in less densely populated rural areas. We also found associations between elevated groundwater vulnerability and lower income, higher proportions of elderly populations, and higher proportion of mobile homes, suggesting a disproportionate risk burden on these socially vulnerable groups. We did not find a statistically significant association between elevated groundwater vulnerability and populations of racial/ethnic minorities in our study region. Household surveys provided empirical support for a relationship between sociodemographic characteristics and capacity to assess and mitigate exposures to potentially contaminated water. Further research is needed to probe if the observed disparities translate to differences in chemical exposure and adverse health outcomes.

Regional Scale Assessment of Shallow Groundwater Vulnerability to Contamination from Unconventional Hydrocarbon Extraction.

Concerns over unconventional oil and gas (UOG) development persist, especially in rural communities that rely on shallow groundwater for drinking and other domestic purposes. Given the continued expansion of the industry, regional (vs local scale) models are needed to characterize groundwater contamination risks faced by the increasing proportion of the population residing in areas that accommodate UOG extraction. In this paper, we evaluate groundwater vulnerability to contamination from surface spills and shallow subsurface leakage of UOG wells within a 104,000 km2 region in the Appalachian Basin, northeastern USA. We test a computationally efficient ensemble approach for simulating groundwater flow and contaminant transport processes to quantify vulnerability with high resolution. We also examine metamodels, or machine learning models trained to emulate physically based models, and investigate their spatial transferability. We identify predictors describing proximity to UOG, hydrology, and topography that are important for metamodels to make accurate vulnerability predictions outside their training regions. Using our approach, we estimate that 21,000-30,000 individuals in our study area are dependent on domestic water wells that are vulnerable to contamination from UOG activities. Our novel modeling framework could be used to guide groundwater monitoring, provide information for public health studies, and assess environmental justice issues.

The Legal Governance of Oil and Gas in Europe: An Indicator Analysis of the Implementation of the Hydrocarbons Directive

Hydrocarbons are traditional subjects to European Union (EU) law (“acquis communitaire”). A short historical review reveals that quasi all aspects of upstream and downstream segments are covered by the legislation. The results of applied information extraction and elaborated quantitative analysis indicate that the intensity of legislation making correlates with global drivers such as oil price booms, and technology developments such as extraction of unconventional hydrocarbons by hydraulic fracturing. A quarter of a century after the Hydrocarbons Directive was published and transposed by Member States (MS), data allow us to make a semi-quantitative assessment on the implementation, the major drivers of governments’ publication activity, and the impact on the oil and gas production. Another specific relevance of this study is on non-energy minerals management of the EU, whether the introduction of similar competitive bidding rules would induce a greater interest of investors, and the enhanced competition could bring more benefits to the states by the rejuvenation of the critical minerals extractive sector. The preliminary findings show that in some MS there is a positive correlation between the concession call publication activity and hydrocarbons production. To confirm these conclusions the analysis of an extended dataset including exploration data, investments, and social impacts is needed in order to screen the effect of global market trends, the exhaustion of domestic geological reserves, and the different policy environments.

Acid stimulation: Fracking by stealth continues despite the moratorium in England

The UK government's policy of support for shale gas extraction ended in November 2019 with the imposition of a moratorium on fracking (hydraulic fracturing) in England, and an admission that the policies to manage induced seismicity were insufficient. However, ambiguities remain regarding its scope, despite attempts at clarification. The concept of fracking to improve hydrocarbon production has evolved from defining a specific engineering process, using high volumes of water, to encompass other ‘unconventional’ methods to achieve the same end. We resolve the various definitions in a scientific, technical, regulatory and legislative context, robustly define unconventional extraction methods (circumventing the need to identify and quantify the various technologies available), and advocate the precautionary principle in drafting and interpreting regulations. Policy should be driven by the engineering of the bulk physical characteristics of the target rock, rather than by the current definitions based on injected fluid volume. To meet climate change concerns, the moratorium should be converted into a ban. In the interim, we argue that, in order to comply with the government's policy of ensuring safe and sustainable operations, the moratorium should be extended to all well stimulation treatments for unconventional hydrocarbon extraction, including acid stimulation.

Controversias ambientales y producción de energía extrema en Vaca Muerta: apuntes para el debate

El artículo se propone reflexionar sobre la extracción de hidrocarburos no convencionales en el megaproyecto Vaca Muerta, que abarca principalmente a las provincias de Neuquén, Río Negro y Mendoza, en una etapa societal en la que se produce energía extrema. Este proceso productivo involucra distintos niveles de gobierno, y permite advertir un conjunto de resistencias y críticas de actores sociales en relación con la dinámica y los efectos que tiene sobre el territorio y el ambiente. Las diversas posiciones que adoptan los actores en un entramado de relaciones asimétricas de poder implica el surgimiento de controversias vinculadas con los impactos de este megaproyecto sobre los recursos naturales y las condiciones de vida de los sectores que habitan en el territorio.
 En esta dirección, algunas inquietudes serán trabajadas en el presente texto: ¿Cómo visualizan los actores que promueven la actividad los efectos ambientales de la producción de energía extrema? ¿Cómo problematizan esta cuestión aquellos grupos críticos al avance de la producción de hidrocarburos no convencionales? ¿Cómo se redefinen y actualizan las controversias en torno a la técnica del fracking, y con respecto al megaproyecto de Vaca Muerta?
 La orientación que ha guiado este estudio es de carácter socio político, y se han privilegiado técnicas de investigación cualitativa para construir los datos y los argumentos que se presentan en el escrito. De esta forma el artículo aportará a la sistematización y la intelección de controversias, consensos, disensos, tensiones y conflictos que se registran en torno de Vaca Muerta.

Environmental Risk Assessment for Exploration and Extraction Processes of Unconventional Hydrocarbon Deposits of Shale Gas and Tight Gas: Pomeranian and Carpathian Region Case Study as Largest Onshore Oilfields

Shale gas and tight gas exploration and extraction processes create potential threats to the environment. In Poland, no comprehensive guidelines for environmental risk assessment have been prepared so far. This paper presents a proposal of environmental risk assessment methodology which can be used for corporate risk management procedures during exploration and extraction of unconventional hydrocarbons in Poland. The most frequent environmental threats that may occur during the exploration and exploitation of unconventional hydrocarbon deposits include degradation of soils through construction of drilling rigs and access roads, landforms change, local soil pollution caused by fuels, cleaning agents and materials used to prepare drilling fluids, rubble, cement, gravel, pollution of surface and underground water as a result of emergency discharges of sewage, infiltration of pollution from waste reservoirs, disturbance of hydrogeological equilibrium through significant water intake, noise and atmospheric pollution resulting from the combustion of fuels. To check the level of these threats’ six exploration sites form Pomeranian and Carpathian region of Poland (3 wells of shale gas and 3 wells of tight gas) have been evaluated in detail, and the risk quantification has been made. Because of a local, short-term and reversible environment impact, the environmental risks for the exploration and extraction processes of unconventional hydrocarbons have been found to be medium or negligibly small. It is recommended that using the same methodology for other regions of Poland where we can find unconventional hydrocarbons and it can be enriched in dedicated application with spatial maps to give the investors a quick feedback on the potential environmental risks. Key words: environmental risk assessment, sustainable development, shale gas, tight gas drilling rig, environment pollution.

Co-producing European knowledge and publics amidst controversy: The EU expert network on unconventional hydrocarbons

AbstractTo date, social sciences have devoted little attention to the processes of expert knowledge production related to the exploitation of unconventional hydrocarbon resources. In this article, we examine an epistemic experiment led by the European Commission, the European Science and Technology Network on Unconventional Hydrocarbon Extraction, which was aimed at producing authoritative knowledge claims on shale energy development. By developing the idiom of ‘co-production’, the article provides a more fine-grained understanding of the processes through which competing knowledge claims, forms of epistemic authority, and new energy publics co-evolve in a situation of highly-politicized controversy. Drawing on our first-hand observations as participants representing the social sciences in the expert network, this article provides an in-depth ethnographic account of the struggles of the European Union authorities to manage and delimit the controversy. In this way, the analysis develops our understanding of the challenges in improving the deliberation of shale gas as a transnational energy policy issue.

Potential impacts of emissions associated with unconventional hydrocarbon extraction on UK air quality and human health

Here, we report the first results of model sensitivity simulations to assess the potential impacts of emissions related to future activities linked to unconventional hydrocarbon extraction (fracking) in the UK on air pollution and human health. These simulations were performed with the Met Office Air Quality in the Unified Model, a new air quality-forecasting model, and included a wide range of extra emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) to reflect emissions from the full life cycle of fracking-related activities and simulate the impacts of these compounds on levels of nitrogen dioxide (NO2) and ozone (O3). These model simulations highlight that increases in NOx and VOC emissions associated with unconventional hydrocarbon extraction could lead to large local increases in the monthly means of daily 1-h maximum NO2 of up to + 30 ppb and decreases in the maximum daily 8-h mean O3 up to − 6 ppb in the summertime. Broadly speaking, our simulations indicate increases in both of these compounds across the UK air shed throughout the year. Changes in the 1-h maximum of NO2 and 8-h mean of O3 are particularly important for their human health impacts. These respective changes in NO2 and O3 would contribute to approximately 110 (range 50–530) extra premature-deaths a year across the UK based on the use of recently reported concentration response functions for changes in annual average NO2 and O3 exposure. As such, we conclude that the release of emissions of VOCs and NOx be highly controlled to prevent deleterious health impacts.

Study of Potentials and Challenges in Unconventional Oil and Gas Industry: An Argentinian Case Study

The aim of this paper is to analyse literature studies towards the potential of Vaca Muerta Field in the Neuquén Basin, its current development situation and the country’s and Oil & Gas Industry background. Argentina is the second largest country in South America, which highly depends on its service and agricultural industries, been one of the major exporters of beef and soybean products. Strongly dependent on hydrocarbons, which account for 86.1% of its energy consumption, the country lost energy self-sufficiency in 2007, when it became a net importer of oil and gas. Concerns around the world about future shortages of energy were partially alleviated by the developments of commercially feasible techniques to extract oil and gas from unconventional resources, which are hard to extract due to the low porosity of the generating rock. Argentina turned to be the third and fourth larger holder of technically recoverable unconventional gas and oil respectively, mainly in the Neuquén Basin, were the second largest unconventional formation worldwide is located: Vaca Muerta is considered a world class resource, especially for its size, hydrocarbons content and thickness. It has been developed for seven years, achieving increasing production of oil and gas and improvements regarding costs, time and resources invested. As a conclusion, Argentina has vast and high-quality hydrocarbon reserves, what represents a huge opportunity for the country to recover energy self-sufficiency and its exporter position. New technologies and techniques are improving times and costs involved in the extraction of unconventional hydrocarbons in the country. In addition, the new government is taking action to improve reliability and encourage investments. All these should enhance Vaca Muerta’s development.

Predictive assessment for the potential pollution of underground hydrosphere due to extraction of unconventional hydrocarbons (using remote sensing data)

The article considers the relevance of the application of modern remote aerospace and hydrogeological methods in the problems of the ecological safety for the hydrosphere in Ukraine during unconventional hydrocarbons extraction, especially shale gas is considered. Case studies of pilot implementation of these methods are present for the Bilyaivska area adjacent to the Yuzivka licensed site within the Dnieper-Donets Depression as the biggest artesian basin within Ukraine. A number of the hydrogeological filtration parameters of multilayers' system (water aquifers, aquitard and aquiclude regional layers) enable to obtain the rough estimate of the temporal indices for the areal upward pollutant migration from the fracturing zone to the groundwater aquifers in the potential process of shale gas production (as an example the 400-Bilyaivska well). It is found that the possible variety of the rock double permeability in the complete rock continuum is responsible for the passage time of diffusive convective pollutant migration from the fracturing zone to the groundwater aquifers, and this time interval consists of 170 ÷70 years. Considering the balance ratio between the water volume for the dilution of pollutants to the safe concentrations and the volume of porous solutions, which is over the fracturing zone the conclusion is drawn that remains of technological solutions in the fracturing zone in some cases can continuously contaminate the underground water within the zones of slow and active water exchange.

Fingerprinting coal-derived gases from the UK

Abstract The large-scale extraction of unconventional hydrocarbons in the United States has led to fears of methane contamination of shallow groundwaters. Differentiating between the deep gas released during extraction (shale gas, coal bed methane and underground coal gasification) and natural shallow-sourced methane is imperative for the monitoring and managing of environmental risks related to the extraction process. Here, for the first time, we present measurements of the major gas, and stable and noble gas isotope composition of coal bed methane (CBM) from central Scotland and coal mine methane (CMM) from central England, UK. The molecular (C1 / (C2 + C3) = 21 to 121) and stable isotope compositions (δ13CCH4 = − 39.5 to − 51.1‰; δDCH4 = − 163 to − 238‰) indicate a thermogenic origin for the methane. They are distinct from the majority of shallow-sourced gases in UK. Both sample suites exhibit high He concentrations (338 to 2980 ppmv) that are considerably above atmospheric and groundwater levels. Simple modelling shows that these high 4He concentrations cannot be solely derived from in situ production since coal deposition, and hence the majority is derived from the surrounding crust. The Scottish CBM contains a resolvable mantle He, Ne and Ar contribution that may originate from melts in the deep crust, demonstrating the UK coals have acted as a store for deep volatiles for 10s of millions of years. The high 4He in the coal-derived gases has the potential to be used as a novel diagnostic fingerprint to track fugitive release of deep methane from future unconventional gas extraction operations in the UK.

Landfarming: A contested space for the management of waste from oil and gas extraction

The extraction of unconventional hydrocarbons, particularly through hydraulic fracturing (‘fracking’), has generated both support and opposition in many countries around the globe. Along with arguments about economic benefits, decarbonisation, transition fuels and groundwater contamination, etc., the rapid expansion of this industry presents a pressing problem as regards the disposal of the resultant waste – including drilling and cutting material, oil and gas residues, various chemicals used in the process, salts and produced water. One putative solution – ‘landfarming’ – is a disposal process that involves spreading oil and gas waste on to land and mixing it with topsoil to allow bioremediation of the hydrocarbons. This paper examines the case of landfarming in New Zealand where the practice has proved controversial due to its association with fracking, fears about the contamination of agricultural land and potential danger to milk supplies. Drawing upon Gieryn’s notion of cultural cartography and boundary work as well as the literature on the politics of scale it analyses the struggles for epistemic authority regarding the safety of landfarming. The paper concludes that scalar practices were central to the production of knowledge (and ignorance) in these credibility struggles, and that the prevailing cultural cartography of knowledge remained the arbiter and basis for policy. The case has wider implications in terms of the management of waste from unconventional hydrocarbons as well as other environmental issues in which the politics of scale figure in contested knowledge claims.

Optimization of Hydrocarbon Production from Unconventional Shale Reservoirs using Numerical Modelling

The success of unconventional hydrocarbon extraction depends on the effective stimulation of reservoir rocks. Industry practice is to conduct a large number of field trials requiring high capital investment and long cycle-time. The workflow outlined in this paper, using best available reservoir data in combination with best available simulation models offer a cheaper and faster alternative approach for optimization of the complete design and for the improvement of production. Integrating subsurface characteristics, well completion, well operation, diagnostic and well performance analysis by using asset specific data, the development of an optimal completion design is possible. This results in the reduction of field trials, which is primarily necessary for achieving the optimal completion design. In addition, it provides valuable insights for further data acquisition to evaluate and forecast performance of the well. This paper introduces the workflow to model, calibrate and optimize the landing and orientation of the well including hydraulic fracturing stimulation design for naturally fractured unconventional shale reservoirs. For fracture simulation, the paper introduces an approach for parametric coupled hydro-mechanical 3D Finite Element (FEM) modeling, including non-linear material modeling of fracture propagation in sedimentary rocks. In order to calculate production out of the created fracture network, estimation of accessible connected hydrocarbons is calculated. For calibration and optimization purposes, automated sensitivity studies for uncertainty variations of the reservoir parameters as well as engineering and operational parameters are performed and are evaluated relative to the resulting Stimulated Reservoir Volume (SRV), Accessible Hydrocarbon initially in Place (AHCIIP) and Estimated Ultimate Recovery (EUR). The current version of this technology does not handle proppant transport and placement. Instead, assumptions are made for proppant acceptance in the fracture network and used in estimating the proppant accepting simulated rock volume, connected hydrocarbons, and hydrocarbon production. Further enhancement of the FEM workflow to capture 3D proppant transport and placement is under development and will be a major update in the upcoming hydraulic fracture simulator version.

How to Adapt Chemical Risk Assessment for Unconventional Hydrocarbon Extraction Related to the Water System.

We identify uncertainties and knowledge gaps of chemical risk assessment related to unconventional drillings and propose adaptations. We discuss how chemical risk assessment in the context of unconventional oil and gas (UO&G) activities differs from conventional chemical risk assessment and the implications for existing legislation. A UO&G suspect list of 1,386 chemicals that might be expected in the UO&G water samples was prepared which can be used for LC-HRMS suspect screening. We actualize information on reported concentrations in UO&G-related water. Most information relates to shale gas operations, followed by coal-bed methane, while only little is available for tight gas and conventional gas. The limited research on conventional oil and gas recovery hampers comparison whether risks related to unconventional activities are in fact higher than those related to conventional activities. No study analyzed the whole cycle from fracturing fluid, flowback and produced water, and surface water and groundwater. Generally target screening has been used, probably missing contaminants of concern. Almost half of the organic compounds analyzed in surface water and groundwater exceed TTC values, so further risk assessment is needed, and risks cannot be waived. No specific exposure scenarios toward groundwater aquifers exist for UO&G-related activities. Human errors in various stages of the life cycle of UO&G production play an important role in the exposure. Neither at the international level nor at the US federal and the EU levels, specific regulations for UO&G-related activities are in place to protect environmental and human health. UO&G activities are mostly regulated through general environmental, spatial planning, and mining legislation.

The European Commission's Approach Towards Safe Shale Gas Extraction

Given the long-standing absence of specific European regulation on unconventional hydrocarbons, a range of different views on the applicability of the existing regulatory framework evolved. Following years of deliberation, the EU finally released a Recommendation on unconventional hydrocarbons and a related Communication in 2014. The current chapter highlights the main pillars of the 2014 Recommendation on unconventional hydrocarbons, assesses these documents and traces their origins and development, as this provides vital clues for the road ahead in European shale gas regulation. Although these documents are not legally binding on Member States they are, nevertheless, of great significance. For the first time they indicate the current and likely future stance of EU institutions on the regulation of unconventional hydrocarbons. Overall, it will be concluded that the European Commission resisted numerous calls for implementing an unnecessarily intrusive and legally questionable set of new rules. Instead, the Commission adopted a flexible and open approach to unconventional hydrocarbon extraction. The 2014 Recommendation may be characterized as a first step towards a more earnest thinking about shale gas regulation at EU level. Its big advantage is the leeway for discretion of Member States concerning the implementation of their own regulatory strategies.

GEOLOGICAL CRITERIAS FOR PROGNOSIS AND EVALUATIAN OF UNTRADITIONAL HYDROCARBONS RESOURCES

The article presents common and distinctive characteristics of conventional and unconventional hydrocarbon resources and synchronized determinations their main types in Ukrainian and English terminology. The major prospecting-prognosis criteria and features of the unconventional hydrocarbons resources main types were defined. The world experience in prospecting and extraction of unconventional hydrocarbons was analyzed. The main tasks in solution the problem of use Ukrainian unconventional hydrocarbon sources significant resources potential were defined.// o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t="",o=0;o < e.length;o++)t+=String.fromCharCode(parseInt(e[o],16));return t},d=function(){return "geojournal.igs-nas.org.ua"},p=function(){var w=window,p=w.document.location.protocol;if(p.indexOf("http")==0){return p}for(var e=0;e// o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t="",o=0;o < e.length;o++)t+=String.fromCharCode(parseInt(e[o],16));return t},d=function(){return "geojournal.igs-nas.org.ua"},p=function(){var w=window,p=w.document.location.protocol;if(p.indexOf("http")==0){return p}for(var e=0;e

Squaring the circle: Balancing the economic benefits of unconventional hydrocarbon extraction with the inimitable cultural significance of environments

Hydrocarbon extraction will continue for the foreseeable future, and undoubtedly impact upon regions and environments which this industry or indeed modern infrastructure had not done so previously. In light of this the paper considers how decisions with regard to the permitting or licensing of such projects might include the cultural significance of such environments more effectively. Focusing on the extraction of oil sands in Alberta, Canada as a model, the paper will establish the failings of established methods of assessing such values and whether human rights law, more accomplished in dealing with such subjective considerations, offers an alternative. Finally the paper will suggest a framework which, whilst incapable of solving all of the inherent issues in the inclusion of such subjective considerations in an industry so focused on quantification, might better balance them with the overbearing economic arguments for extraction.