An integrated assessment of UK Shale resource distribution based on fundamental analyses of shale mechanical & fluid properties.

Lead Research Organisation: British Geological Survey
Department Name: Energy & Marine Geoscience

Abstract

Shale gas has the potential to transform the UK's future energy security. With imports currently accounting for 50% of its domestic gas requirements, projected to rise to roughly 80% by 2035, the big question is 'Are there enough shale gas resources to effectively replace the declining North Sea and Irish Sea gas production, and for how long?' The largest unknown is the potential gas reserves (i.e. recoverable resources) that would be commercially viable to be produced in the UK. There have been a number of differing in-place estimates for the Upper Bowland Shale in the northern England Carboniferous, ranging from 164-447 tcf suggested by Andrews (2013), to 8-19 tcf quoted by Uguna et al. (2017). In the absence of flow test data, reliable recoverable reserves estimates could not have been published. There has been a single well test carried out by Cuadrilla in Lancashire, the results of which have not yet been made public. The industry, the scientific community, the government, and environmental scientists, have been starved of modern borehole electric log, core and well test data with which to assess both resource potential and the associated environmental impact. This is about to change, with drilling planned to take place during the course of the proposed study in Cheshire, Lancashire, North Yorkshire, and North Nottinghamshire.
This research project will focus on the Carboniferous (Bowland Shale) basins of the East Midlands, Lancashire, Cheshire, and Yorkshire. The vision is of a multidisciplinary approach to solving problems in the main research focus areas set out in Challenge 2 of the NERC call. We will bring together key researchers from several institutions around the UK, working on UK shale science from the micro-pore (<10 nm) to the basin scale. Key aspects of shale mineralogy, petrology, geochemistry, stratigraphy, rock mechanics, gas generation and adsorption and fluid flow in low porosity rocks will be combined into a holistic basin-scale model to generate a better scientifically-grounded set of estimates. Key sensitivities related to input parameters will be tested, and more importantly, compared/contrasted with available production data from the planned wells .
The outcome of this 4-year project will be a more scientifically defendable assessment of the location and magnitude of UK shale resources, guided by an improved understanding of the shale properties and fluid flow through the shale, before, during and following hydraulic fracturing to ascertain whether shale gas has the potential to have a marked impact on energy security in the UK for several decades into the future. This project will critically inform the key stakeholders (Government, Industry, Academia, and the general public) of UK shale potential, and will provide input to discussions on future UK energy strategy. Collaboration with those projects funded within the other Challenges in this programme will allow us to assess whether or not this resource can be accessed in a commercially viable and environmentally responsible way.

References
Andrews, I.J. 2013. The Carboniferous Bowland Shale: Geology and resource estimate. British Geological Survey for the Department of Energy and Climate Change, London, UK.
Uguna, C., Snape, C., Vane, C., V. Moss-Hayes, V., Whitelaw, P., Stevens, L., Meredith, W. and Carr, A. 2017. Convergence of shale gas reserve estimates from a high pressure water pyrolysis procedure and gas adsorption measurements. 28th International Meeting on Organic Geochemistry, 17-22 September 2017, Florence, Italy.

Planned Impact

The research carried out in the proposed project will address to fundamental questions related to UK Shale gas. Namely: How much gas and where is it located? Stakeholder interest in accessing new, scientifically calibrated estimates of resources and reserves will be of immense scientific, industry and public interest. Government will also use these outcomes to inform energy policy in the UK for potentially the next 20 years. Regular communication with the other Challenges in this call and industrial partners will take place at a minimum of 6 month intervals. There will also be formal reporting requirements to the funding bodies.

Beneficiaries

Industry
Depending on which current shale gas resource estimates we take (BGS: Andrews 2014) or Urgano (2017) and the recovery factor applied (nominally 10%) the UK would appear to have between 10 and 50 years of potential gas supply from the northern England Carboniferous basins. Assuming UK gas consumption continues at the current rate of approximately 2.7tcf/year. The value of narrowing the range on this estimate cannot be understated. Working with industry partners we can critically test current and evolving academic models of pore and fracture systems in shales against new data acquired by industry. The models will be re-calibrated with real well bore and test data to provide revised models of pore and fracture behaviour. The key to industry and the country is more efficient exploration and exploitation activities. Fewer wells, fewer pads equals less disruption, less emissions and consequently minimised environmental impact.

Government
Having a scientifically supported range of resource estimates for UK shale gas and its location is of immense value to government in terms of framing UK energy policy going forward. CO2 emission commitments require a cleaner energy policy based on gas rather than coal and oil and a resource that is indigenous from either the North and Irish seas and potentially onshore UK. This mitigates emissions related to transportation and the valid criticism that imported gas is just shifting the problem onto someone else.

General Public
One of the key roles we have to play as an informed group is in explaining to the general public from a scientific expert point of view the key pluses and minuses associated with shale gas and the impact of fracking and a potentially large resource might have on industrialisation and environment in the areas we identify that may contain the gas resources.

Publications

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Hennissen J (2019) Total organic carbon in the Bowland-Hodder Unit of the southern Widmerpool Gulf: a discussion in Journal of Petroleum Science and Engineering

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Hennissen J (2024) The Bowland Shale Formation in the Blacon Basin: palaeoecology and resource potential in Geological Society, London, Special Publications

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Jack Walker (2023) Cross-Basin Analysis of Bowland Basin Deposition, Upper Mississippian using Mo and U in Geological Society, London, Special Publications

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Jan A. I. Hennissen (2023) The Bowland Shale Formation in the Blacon Basin: palaeoecology and resource potential in Geological Society, London, Special Publications

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Joe F Emmings (2023) The Holywell Shale Formation in the Blacon Basin: syngenetic processes, stacking patterns and heat productivity in Geological Society, London, Special Publications

 
Description The main aims of the research grant were to assess the unconventional resources in the ground and how much is commercially recoverable. Despite many changes to the regulatory framework surrounding unconventional hydrocarbon exploration (see below), we managed to make resource assessments for the most promising targets in northern England. Especially the finding that many of the target mudstones (e.g. Bowland Shale Formation) are far more heterogeneous and their generative potential much lower than previously thought is a key finding. This restricts the commercial viability of an unconventional hydrocarbon industry onshore in the UK. Furthermore, it was revealed that many faults and fractures, some below the resolution of seismic surveying equipment, complicate the safe extraction of the resource.

At the start of Grant NE/R018065/1, in August 2018, a moratorium on hydraulic fracturing existed only in Scotland and Wales which remained in place for the duration of this grant. In England a moratorium was first imposed in November 2019, following seismic activity during drilling operations at Cuadrilla's Preston New Road Site. In September 2022, the moratorium was lifted in England after which it was re-instated in November 2022. The latest changes directly resulting from outcomes of Grant NE/R018065/1 and its parent and sister grants, united in the Unconventional Hydrocarbons in the UK Energy System (UKUH) research consortium. Two (out of four) authors of the commissioned report which informed the government on hydraulic fracturing (https://www.gov.uk/government/publications/review-of-the-geological-science-of-shale-gas-fracturing) and the unconventional hydrocarbon potential in the UK were PI and Co-I on Grant NE/R018065/1.
Exploitation Route 1) Improved resource assessment techniques. The outcomes of Grant NE/R018065/1 provide a bottom-up approach to assessing a natural resource. The traditional way of conducting resource assessments, especially in the hydrocarbons industry, is a top-down approach relying on vast amounts of data from an established industry. For the UK, an onshore unconventional hydrocarbons industry is non-existent and no such data were available. Therefore, we provided a scientific workflow that allowed a resource assessment in the absence of production data.

2) Heterogeneity of mudstones. The most promising unconventional hydrocarbon targets are fine-grained, organic rich mudstones. We have shown in the course of Grant NE/R018065/1 that these seemingly homogeneous strata are in fact very variable in chemical composition and generative potential. This is especially relevant in other subsurface geo-energy activities (e.g., CCUS) and the deep geological storage of nuclear waste which also target mudstones. We already adopted workflows and code to analyse X-ray fluorescence results, designed in the current grant, in projects that research the viability of certain mudstones for the storage of nuclear waste.
Sectors Energy,Environment,Government, Democracy and Justice

URL https://www.gov.uk/government/publications/review-of-the-geological-science-of-shale-gas-fracturing
 
Description Work done as part of this grant has been used to document a reduced estimate of unconventional gas in the subsurface. This led to a re-assessment of the future of unconventional hydrocarbon exploration and ultimately to a moratorium on hydraulic fracturing (November 2019), effectively stopping onshore exploration. In April 2022 the government commissioned The British Geological Survey to advise on the latest scientific evidence around shale gas extraction (https://www.gov.uk/government/publications/review-of-the-geological-science-of-shale-gas-fracturing). Two (of four) authors of this report were PI and Co-I on Grant NE/R018065/1 and the results of the commissioned report relied on the outcomes of this grant and its parent and sister grants, united in the Unconventional Hydrocarbons in the UK research consortium (http://www.ukuh.org/). The commissioned report had an immediate impact, the moratorium was restored, and its release dominated national news headlines (e.g., https://www.bbc.co.uk/news/uk-politics-62990021)
First Year Of Impact 2019
Sector Energy,Environment,Government, Democracy and Justice
Impact Types Societal,Policy & public services

 
Title Update on the development of Vitrinite Reflectance on strew mounted organic matter as a tool to assess thermal maturity 
Description The Vitrinite Reflectance technique on strew mounted organic matter has now been tested and is being implemented at the BGS as a tool for thermal maturity estimates. First results from the Preese Hall-1, Grange Hill-1z and Becconsall-1z have been incorporated in a larger study of the Bowland Basin in collaboration with Leicester University. A first draft of a manuscript has been distributed and will be submitted in 2020 with the Journal of Marine and Petroleum Geology as the target journal. 
Type Of Material Improvements to research infrastructure 
Year Produced 2019 
Provided To Others? No  
Impact Vitrinite reflectance is routinely used with coals and conventional hydrocarbon targets. We will now explore how more effectively implement this technique for the Carboniferous dark shales which are the target of the resource assessment conducted as part of Award. This technique will be crucial in basin analysis to determine the maximum depth sediments have been buried at. This is a transferable skill which has applications in assessing the right reservoir for carbon capture and storage (CCS). 
 
Title Vitrinite Reflectance on Dispersed Organic Matter in Organic Rich Dark Shales 
Description Background The aim of the work undertaken as part of Award NE/R017964/1 is to reassess the resource assessment published by Andrews (2013) in light of the new data that has been generated since then. Recent publications (Hennissen et al., 2017; Hennissen and Gent, 2019) highlighted current resource assessments rely heavily on calculated Vitrinite Reflectance (VR) rather than actual VR analysis, which has a higher degree of uncertainty resulting in less accurate resource estimation that are communicated to the public. Vitrinite Reflectance is the most widely used and is demonstrably most robust tool to assess the thermal maturity of organic matter in conventional and unconventional systems. Thermal maturity is a vital parameter to constrain resource assessments because it reflects the burial depth sediments have been exposed to which ultimately determines how much hydrocarbons are retained in the surrounding formations. Vitrinite reflectance determination is a vital skill that was missing from the energy portfolio at the British Geological Survey (BGS). Co-funded by BGS, I attended a two week training course with Prof. Paulo Fernandes at the Universidade do Algarve to gain a working knowledge of the technique (preparation and analysis) for BGS to be self-sufficient for VR analysis. With additional funding from the BGS we acquired standards to calibrate existing equipment (reflected light microscope with a 50X oil immersion objective) and laboratory consumables to prepare samples using our existing infrastructure (the Biostratigraphy and Palaeontology Laboratory). Vitrinite reflectance is routinely used with coals and conventional hydrocarbon targets. We will now explore how more effectively implement this technique for the Carboniferous dark shales which are the target of the resource assessment conducted as part of Award. In the future we will also explore how image analysis can be used to partly automate this technique to make analysis more efficient. References Andrews, I.J., 2013. The Carboniferous Bowland Shale Gas Study: Geology and Resource Estimation. British Geological Survey for the Department of Energy and Climate Change, London, UK, pp. 64. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/226874/BGS_DECC_BowlandShaleGasReport_MAIN_REPORT.pdf. Hennissen, J.A.I., Gent, C.M.A., 2019. Total Organic Carbon in the Bowland-Hodder Unit of the southern Widmerpool Gulf: a discussion. J. Pet. Sci. Eng. https://doi.org/10.1016/j.petrol.2019.01.097. Hennissen, J.A.I., Hough, E., Vane, C.H., Leng, M.J., Kemp, S.J., Stephenson, M.H., 2017. The prospectivity of a potential shale gas play: an example from the southern Pennine Basin (central England, UK). Mar. Petrol. Geol. 86, 1047-1066. https://doi.org/10. 1016/j.marpetgeo.2017.06.033. 
Type Of Material Improvements to research infrastructure 
Year Produced 2019 
Provided To Others? No  
Impact We will implement the above described technique during the course of this award and tangible outcomes are expected to be published in peer-reviewed journals in 2020. 
 
Title Palynology, Rock-Eval and Thermal Maturity data for the Holywell Shale Formation from the Ellesmere Port 1 Borehole 
Description Four data tables are included: 1. Rock-Eval 6 pyrolysis and stable isotope data: includes sample number; Depth in meters; S1, S2, S3, present day hydrogen index, present day oxygen index in milligram hydrocarbons per grams of rock; Tmax in degrees Celsius; total organic carbon (TOC), pyrolyzed carbon (PC), remaining carbon (RC) in %; proportion of TOC that is pyrolyzed in %; d13C in ‰. 2. Palynological counts: raw counts of the palynofacies analysis. Includes MPA (micropalaeontology sample number), SSK (subsample Keyworth) number provided by the National Geological Repository; Depth in meters; the raw counts grouped by Heterogeneous amorphous organic matter (AOM), Homogeneous AOM, Phytoclasts, Spores and Pollen, Fungal debris and Mineral Matter. 3. Thermal Maturity as random mean vitrinite reflectance data: includes SSK sample number, depth in meters; mean random vitrinite reflectance (%Rr), Standard Deviation (SD) and the number of measurements taken for each sample (n). 4. Spore counts: Includes MPA (micropalaeontology sample number), SSK (subsample Keyworth) number provided by the National Geological Repository; Depth in meters; raw counts of spores identified in selected samples. All the data are based on sample materials from the Holywell Shale Formation from the Ellesmere Port 1 Borehole. These data are in support of: Hennissen et al.'s The Holywell Shale Formation in the Blacon Basin: resource potential in the Geological Society of London Special Publications. 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
Impact This work allowed the development of a scientific work flow to conduct unconventional hydrocarbon research. it informed a government commissioned report on the assessment of extraction of unconventional hydrocarbons and contributed to the resource assessment of the Blacon and Bowland Basins. 
URL https://www2.bgs.ac.uk/nationalgeosciencedatacentre/citedData/catalogue/cdc7153f-f3ed-4c5e-b07a-7a9a...
 
Description Collaboration with the University of Nottingham and the Horizon 2020 SECURe project (ENER/H2020/764531/"SECURe") 
Organisation University of Nottingham
Department School of Chemistry Nottingham
Country United Kingdom 
Sector Academic/University 
PI Contribution Jan Hennissen (PI) and Ed Hough (Team Member) are involved in the Horizon 2020 project SECURe (securegeoenergy.eu) with the University of Nottingham also being a partner. One of the proposed topics in SECURe (potential targets for unconventional resources in the UK) overlapped with the research topics of the current grant NERC-UKUH. As part of NERC-UKUH we investigated Bowland Shale equivalent materials and characterized it lithologically, which was then complemented by the first author as part of the SECURe project.
Collaborator Contribution As part of the UKUH-NERC consortium, Jan Hennissen and Ed Hough investigated core materials of geological formations that were deemed prospective for unconventional hydrocarbons. We specifically target pyrite-rich intervals which would be of interest to our partner (University of Nottingham) who investigated element mobilization as a consequence of the use of hydraulic fracturing fluids.
Impact At the moment we co-authored one paper: https://doi.org/10.1016/j.fuel.2020.119914
Start Year 2019
 
Description Workshop as part of the NERC Unconventional Hydrocarbons in the UK Energy System Annual meeting 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact I organised, in collaboration with Rachel Brown (Newcastle University), the 1st Annual Science Meeting for the Unconventional Hydrocarbons in the UK Energy System Programme (UKUH 2019) at The British Geological Survey (BGS) on 17/09 and 18/09/2019 with 75 participants over both days (http://www.ukuh.org/events/annualsciencemeeting1/). The program, attached, included technical talks and panel discussions divided into four sessions:
• Session 1: Upscaling; sample availability
• Session 2: Public Perception
• Session 3: Regulations, planning and environmental considerations
• Session 4: Transport of gas 'Is it going to flow?'
The programme also included a core workshop at the National Geoscience Data Centre where we showed core material from thirteen boreholes originating from different Carboniferous basins: the Widmerpool Gulf, the Bowland Basin, the Cleveland Basin and the Craven Basin. During the meeting we also offered the opportunity to the different challenges to discuss progress in 5 breakout sessions
Year(s) Of Engagement Activity 2019
URL http://www.ukuh.org/events/annualsciencemeeting1/