User guide for the BGS UK Coal Resource for New Exploitation Technologies (Version 1) dataset

This report describes the Coal for New Technologies GIS dataset, which is a suite of data layers developed in 2004 by the British Geological Survey (BGS), with the assistance of Wardell Armstrong and Imperial College, London. The principle aim of the original study was to develop a methodology to assess the potential of the UK onshore coal resources for both exploitation by conventional (mining) and new technologies. Digital data was created using a Geographic Information System (GIS) to produce the delivered output of the original project, a series of paper maps that would identify prospective areas. The Coal for New Technologies digital data has been derived from the original source data. No updating has been carried out and has been published in its original format under Open Government Licence as a set of data layers covering mining technologies: Mining Technologies: Area with technical potential for opencast workings (source Coal Resource Map of Great Britain BGS/Coal Authority 1999) Underground mining exploration prospects Good prospects for abandoned mine methane (AMM) (Mine workings not recovered) Resource area for coal mine methane (CMM) (source Coal Authority Underground Licences, May 2002) Extent of underground workings with 500m buffer zone (based on Coal Authority data, May 2002) New Technologies: Area greater than 1200m from surface with potential for CO2 sequestration Area with good coalbed methane (CBM) potential Underground coal gasification (UCG) potential Coalbed methane (CBM) resource area Coal-bearing strata The original methodology is described in the project report which outlines the assessment, development and uncertainties of the methodology which is available as a free download on the BGS website here: http://www.bgs.ac.uk/downloads/start.cfm?id=1712

Carboniferous stratigraphical correlation and interpretation in the Irish Sea

This report systematically details the stratigraphy and palaeogeography of Carboniferous rocks of the UK Irish Sea for the 21CXRM Palaeozoic project. Each stratigraphical group of Carboniferous or Permian age is described in turn. This report describes the stratigraphical correlation of Carboniferous strata of the report area using principally well data, but incorporates information from new seismic interpretations (Pharaoh et al., 2016a) to identify key unconformities. The report provides: a systematic description of a spatially and temporally variable Carboniferous succession; Permian strata are also described for the succession above the Variscan Unconformity; a full incorporation of onshore knowledge is provided given the often limited offshore well data; a series of four correlation panels of key offshore and onshore wells/boreholes; a series of eight palaeogeogeographical maps which highlight the potential regional distribution of source and reservoir rock facies through selected time intervals during the Carboniferous. A spreadsheet of well tops accompanies this report

Palaeozoic petroleum systems of the Irish Sea

This report synthesises the results of the 21CXRM Palaeozoic project in the Irish Sea to describe the Palaeozoic petroleum systems of that area. One hydrocarbon play system dominates the basin system: Namurian organic-rich marine shales (Bowland Shale Formation) generated oil and gas with a peak during maximum burial of the system in late Jurassic/early Cretaceous time. These hydrocarbons passed to reservoirs in the Triassic Ormskirk Sandstone (Sherwood Sandstone Group) by way of structures generated during the Variscan Orogeny and Cenozoic inversion, resulting in the Morecambe, Hamilton and other gas and oil fields The Palaeozoic study of the wider Irish Sea area has assessed the potential for more widespread petroleum systems situated outside the well-known play, particularly within the Carboniferous. Within the Main Graben system of the East Irish Sea Basin, Coal Measures strata were partially removed following Variscan inversion and early Permian uplift. They are not rich in coals, and not inferred to be a significant source rock. There is some potential in the Millstone Grit and Yoredale sequences, as some shales (particularly those associated with marine bands) are known to have high Total Organic Contents. The source rock potential of shales within the Carboniferous Limestone sequence is poorly constrained by data. A Devonian source rock is unproven and considered unlikely. Potential Namurian source rocks, such as the Yoredale Group, have been largely eroded in the Peel and North Channel basins, considerably reducing their prospectivity, although terrestrial sequences of equivalent age in the Solway Basin may offer better potential. The variable seismic data quality at Carboniferous levels and sparsity of deep well control have led to challenges in interpretation, particularly of the deeper picks. The interpretation of the surfaces contains a strong model-driven element, evidenced by the onshore relationships and areas where seismic picks can be made with the greatest confidence. Based upon the integration of regional seismic mapping with a limited well, source rock and reservoir property dataset, the most prospective parts of the region, outside the Ormskirk conventional gas play, are considered to be: The thick Westphalian sequences preserved in the Eubonia Tilt-Block in Quadrant 109, outside the main Permian-Mesozoic graben system and unaffected by Cenozoic inversion. The presence and quality of seals form a major risk as the Cumbrian Coast Group seal is thin or absent and Carboniferous intraformational seals are required but untested. Based on the limited dataset available in adjacent basins, reservoir quality is also a significant risk. A belt of Variscan inversion structures correlated with structures on the Formby Platform, and Ribbledale Foldbelt onshore, from which hydrocarbons have leaked into the overlying, Ormskirk-hosted Hamilton fields. The biggest risk here is whether reservoirs remain unbreached at the Pre-Permian level, and retain good poroperm characteristics at depths of about 2500 m. A more speculative play lies in the extensive carbonate platform in Quadrant 109 and surrounding the Isle of Man, in reefal facies with enhanced secondary porosity. Here, source rock presence and migration pathways, reservoir properties and seal quality are major risks

DECC/BGS assessment of resource potential of the Bowland Shale, UK

This paper reviews the results of the DECC-commissioned 2012-13 BGS study to estimate the shale gas resource assessment of the Carboniferous Bowland Shale in central Great Britain. Over 15,000 miles of seismic data were interpreted and integrated with well and outcrop control, BGS mapping, 3D depth modelling, geochemical analysis, and 2D thermal maturity basin modelling. The Bowland Shale, and its laterally equivalent basinal shale formations are known to be important source rocks. The study recognised two depositional units; an organic-rich upper part that is a widespread marine shale unit drowning most platform highs and a lower unit comprised of very thick rift-basin fill shales with mass-flow carbonates and rare mass-flow sandstones, passing laterally to platform carbonates on the paleo-highs. An interpreted top gas window thermal maturity surface was integrated with the depth structure mapping to identify the volume of Bowland shale in the gas window which was used as one of the input parameters for a Monte Carlo simulation of the in-place gas resources. The study estimates a large volume of gas in the shales beneath the UK, but concludes that not enough is known yet to estimate a recovery factor, nor to estimate potential reserves

UK Coal resource for new exploitation technologies. Final report

This focus of this report are the UK coal resources available for exploitation by the new technologies of Underground Coal Gasification, Coalbed Methane production and Carbon Dioxide Sequestration. It also briefly considers the potential for further underground and opencast mining and the extraction of methane from working and closed mines. The potential for mining was mainly considered because it has a bearing on the scope for the new exploitation technologies rather than to identify resources or potential mine development areas. The report covers the UK landward area and nearshore areas, although information on the extent of underground mining was not available for the nearshore areas. This work was carried out by the British Geological Survey, with the assistance of Wardell Armstrong and Imperial College, London. It represents a summary of the results of the Study of the UK Coal Resource for New Exploitation Technologies Project, carried out for the DTI Cleaner Coal Technology Programme (Contract No. C/01/00301/00/00) under the management of Future Energy Solutions (Agreement No. C/01/00301/00/00). Coalbed methane production can be subdivided into three categories: Methane drained from working mines, known as Coal Mine Methane (CMM), has been exploited in the UK since at least the 1950s. Currently all working mines except Daw Mill and Ellington drain methane. It is used to generate electricity at Harworth, Tower and Thoresby collieries and in boilers at Welbeck, Kellingley and Ricall/Whitemoor collieries. There is potential to increase the exploitation of CMM in the UK but this is mainly a question of economics. There is also an environmental case for further utilisation, as methane is an important greenhouse gas, 23 times more powerful than carbon dioxide on a mass basis. Methane drained from abandoned mines, known as Abandoned Mine Methane (AMM), is a methane-rich gas that is obtained from abandoned mines by applying suction to the workings. The fuel gas component consists primarily of methane desorbed from seams surrounding the mined seam(s). These unmined seams have been de-stressed and fractured by the collapse of overlying and underlying strata into the void left by the extracted seam(s). Currently AMM is being exploited at sites in North Staffordshire (Silverdale Colliery), the East Midlands (Bentinck, Shirebrook and Markham collieries) and Yorkshire (Hickleton, Monk Bretton and Wheldale collieries). The methane-rich gas is used for electricity generation or supplied to local industry for use in boilers and kilns. Over the last few years, the fledgling UK AMM industry has started to ascend a learning curve. However, it has suffered a major setback since the wholesale price of electricity fell under the New Electricity Trading Arrangements and AMM does not currently qualify as renewable energy in the UK. Coalbed methane produced via boreholes from virgin coal seams, known as Virgin Coalbed Methane (VCBM), has been the subject of significant exploration effort in Lancashire, North Wales, South Wales and Scotland. The best production of gas and water from a single well is understood to be from the project at Airth, north of Falkirk in Scotland. However, this is not economic at present. The main reason for the slow development of VCBM in the UK is perceived to be the widespread low permeability of UK coal seams, although little work has been carried out in the UK on coal permeability, or to truly identify the reasons for the lack of success. This must be overcome before the otherwise significant resource bases in the Clackmannan Syncline, Canonbie, Cumbria, South Lancashire, North Wales, North Staffordshire and South Wales coalfields can be exploited. A technological breakthrough is required to overcome the likely widespread low permeability in the UK Carboniferous coal seams. Otherwise, at best, production will probably be limited to niche opportunities in areas where high seam permeability exists. The criteria used to define and map the location of VCBM resources are as follows: • Coal seams greater than 0.4 m in thickness at depths >200 m • Seam gas content >1m3/tonne • 500 metres or more horizontal separation from underground coal workings • Vertical separation of 150m above and 40 m below a previously worked seam Vertical separation of >100 m from major unconformities of these areas is thought to be about ,900 x 109 m3 (about 29 years of UK natural gas consumption). he main criteria sed for the delineation and mapping of resource areas with potential for UCG were: eparation from underground coal workings and current omic and environmental grounds as described later in this report. he establishment of these criteria do not rule out UCG projects in shallower or thinner seams, if • Vertical separation of >100 m from major aquifers, and • Areas with a CMM resource (current underground coal mining licences) were excluded. Note that the presence of a CBM resource does not imply permeability in the coal seams or that the resource can be recovered economically now or at any time in the future. Using these criteria resource areas were defined and represented on the maps. The total VCBM resource 2 Underground coal gasification (UCG) is the process whereby the injection of oxygen and steam/water via a borehole results in the partial in-situ combustion of coal to produce a combustible gas mixture consisting of CO2, CH4, H2 and CO, the proportions depending on temperature, pressure conditions and the reactant gases injected. This product gas is then extracted via a producing well for use as an energy source. All previous trials of this technology in the UK took place in the 1950’s or before, e.g. Durham (1912), Newman Spinney (1949-1956) and Bayton (c.1955), although this country is well placed for UCG, with large reserves of indigenous coal both onshore and offshore. T u • Seams of 2 m thickness or greater • Seams at depths between 600 and 1200 m from the surface • 500 m or more horizontal and vertical scoal mining licences, and • Greater than 100 m from major aquifers While seams outside these depth and thicknesses criteria are known to support UCG, the criteria were chosen for this generic study on econ T local site specific factors support it. Mapping of the potential UCG resource has identified large areas suitable for UCG, particularly in Eastern England, Midland Valley of Scotland, North Wales, Cheshire Basin, South Lancashire, Canonbie, the Midlands and Warwickshire. Potential also exists in other coalfields but on a smaller scale; this is often limited by the extent of former underground coal mining activities. The total area where coals are suitable for gasification is approximately 2.8 x 109m2. Where the criteria for UCG are met, the minimum volume of coal available for gasification, calculated assuming only one 2 m thick seam meets the criteria across each area, is app63 roximately 5,698 x 10 m (~7 Btonnes). Using an verage of the total thickness of coals that meet the criteria across each area gives a more realistic source figure of 12,911 x 106m3 (~17 Btonnes). pass the expensive step of parating the CO2 from flue gases. If the main objective, however, is CO2 sequestration rather than ethane production then separation of the flue gases may be worthwhile. O2 on coal seams, is would render them unminable and ungasifiable (because the CO2 would be released). Any future ining of such coals would require re-capture and sequestration of the stored CO . ion, providing that other issues, such as low seam permeability, can be vercome. Large areas where coal is below 1,200 m occur in the UK, particularly in the Cheshire asin and Eastern England. In summary • and its potential application in the UK cannot be assessed. However, there are vast areas of coal at depths below 1,200 m that are possibly too deep for mining and in situ gasification

An overlooked play? Structure, stratigraphy and hydrocarbon prospectivity of the Carboniferous in the East Irish Sea–North Channel basin complex

Seismic mapping of key Paleozoic surfaces in the East Irish Sea–North Channel region has been incorporated into a review of hydrocarbon prospectivity. The major Carboniferous basinal and inversion elements are identified, allowing an assessment of the principal kitchens for hydrocarbon generation and possible migration paths. A Carboniferous tilt-block is identified beneath the central part of the (Permian–Mesozoic) East Irish Sea Basin (EISB), bounded by carbonate platforms to the south and north. The importance of the Bowland Shale Formation as the key source rock is reaffirmed, the Pennine Coal Measures having been extensively excised following Variscan inversion and pre-Permian erosion. Peak generation from the Bowland source coincided with maximum burial of the system in late Jurassic–early Cretaceous time. Multiphase Variscan inversion generated numerous structural traps whose potential remains underexplored. Leakage of hydrocarbons from these into the overlying Triassic Ormskirk Sandstone reservoirs is likely to have occurred on a number of occasions, but currently unknown is how much resource remains in place below the Base Permian Unconformity. Poor permeability in the Pennsylvanian strata beneath the Triassic fields is a significant risk; the same may not be true in the less deeply buried marginal areas of the EISB, where additional potential plays are present in Mississippian carbonate platforms and latest Pennsylvanian clastic sedimentary rocks. Outside the EISB, the North Channel, Solway and Peel basins also contain Devonian and/or Carboniferous rocks. There have, however, been no discoveries, largely a consequence of the absence of a high-quality source rock and a regional seal comparable to the Mercia Mudstone Group and Permian evaporites of the Cumbrian Coast Group in the EISB

Scientific rationale for Uranus and Neptune <i>in situ</i> explorations

The ice giants Uranus and Neptune are the least understood class of planets in our solar system but the most frequently observed type of exoplanets. Presumed to have a small rocky core, a deep interior comprising ∼70% heavy elements surrounded by a more dilute outer envelope of H2 and He, Uranus and Neptune are fundamentally different from the better-explored gas giants Jupiter and Saturn. Because of the lack of dedicated exploration missions, our knowledge of the composition and atmospheric processes of these distant worlds is primarily derived from remote sensing from Earth-based observatories and space telescopes. As a result, Uranus's and Neptune's physical and atmospheric properties remain poorly constrained and their roles in the evolution of the Solar System not well understood. Exploration of an ice giant system is therefore a high-priority science objective as these systems (including the magnetosphere, satellites, rings, atmosphere, and interior) challenge our understanding of planetary formation and evolution. Here we describe the main scientific goals to be addressed by a future in situ exploration of an ice giant. An atmospheric entry probe targeting the 10-bar level, about 5 scale heights beneath the tropopause, would yield insight into two broad themes: i) the formation history of the ice giants and, in a broader extent, that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. In addition, possible mission concepts and partnerships are presented, and a strawman ice-giant probe payload is described. An ice-giant atmospheric probe could represent a significant ESA contribution to a future NASA ice-giant flagship mission

Lithostratigraphy of the Sherwood Sandstone Group of England, Wales and south-west Scotland

This review was commissioned by the BGS Stratigraphy Committee under the Chairmanship of John Powell and Colin Waters. It is based on a synthesis of new stratigraphical information on the Sherwood Sandstone Group acquired since the publication, in 1980, of the Geological Society of London Special Report ‘A correlation of Triassic rocks in the British Isles’ (Warrington, 1980). During this period, numerous BGS geological survey projects have acquired new knowledge of the Sherwood Sandstone Group succession in England and Wales, and many BGS colleagues provided us with information and expertise to assist with this review. Among these, we particularly wish to thank, D McC Bridge, N S Jones, J N Carney, A H Cooper, A J Newell, R G Crofts, A S Howard and S Holloway for information on local Triassic successions, advice on geophysical log correlation, and for comments on earlier drafts of the report. The report has been edited by Joanna Thomas and has benefited from the comments of former and present members of the BGS Stratigraphy Committee, notably the chairman, John Powell, and his successor Colin Waters and from external reviews by Mark Hounslow and Nigel Mountney on behalf of the Stratigraphy Commission, Geological Society of London. Cartography in this report is by Paul Lappage and Henry Holbrook

Hydrogen exploration : a review of global hydrogen accumulations and implications for prospective areas in NW Europe

From a geological perspective, hydrogen has been neglected. It is not as common as biogenic or thermogenic methane, which are ubiquitous in hydrocarbon basins, or carbon dioxide, which is common in geologically active areas of the world. Nevertheless, small flows of hydrogen naturally reach the Earth’s surface, occur in some metal mines and emerge beneath the oceans in a number of places worldwide. These occurrences of hydrogen are associated with abiogenic and biogenic methane, nitrogen and helium. Five geological environments are theoretically promising for exploration based on field, palaeofluid and theoretical evidence: ophiolites (Alpine, Variscan and Caledonian in order of decreasing prospectivity), thinned-crust basins (failed-arm rifts, aulacogens), potash-bearing basins, basement in cratonic areas and the Mid-Atlantic ridge and its fracture zones. The subsurface areas of these environments are relatively poorly known, compared to hydrocarbon basins. Hydrogen shows may indicate larger reserves in the subsurface, in a similar way to the beginnings of hydrocarbon exploration in the 19th century. The main source of hydrogen is ultramafic rocks, which have experienced serpentinization, although other generation processes have been identified, including biogenic production of hydrogen during very early stages of maturation and radiolysis. There are two main tectonic settings where serpentinization has operated. The main accessible onshore areas are where ophiolites are found tectonically emplaced within fold belts. Potentially much larger investigation areas lie in the subsurface of some ophiolites. These areas generally lie outside hydrocarbon provinces. However, where thrusting has emplaced ophiolites over a hydrocarbon-bearing foreland basin, tests involving sub-thrust conventional hydrocarbon exploration plays could also be employed to search for hydrogen. The other main tectonic setting is in highly extended basins, for example failed rifts or aulacogens, where thick sediments overlie thinned or absent crust above probably serpentinized mantle. These structures occur offshore on continental margins and extend onshore into long-lived rifts which have been reactivated and rejuvenated repeatedly. Conventional seismic reflection data are already available in these areas, but deep subsurface resolution is poor where there are extensive volcanic rocks. Analogues of these occurrences are also found in the deep oceans, along the mid-ocean ridges and offsetting transform faults. Here, thin crust and faulting may facilitate serpentinization of the mantle rocks by seawater ingress. Further research should aim to identify the extent of the hydrogen flux and its probable dominant role in the abiogenic production of hydrocarbons in Precambrian times, a natural process now largely replaced by biogenic participation. A similar industrial process replicates serpentinization, producing hydrogen and ultimately liquid hydrocarbons on a commercial scale in some countries. It remains to be proved whether a contribution from exploration can be made to any future hydrogen economy