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This paper is concerned with the socio-spatial and ethical politics of redistribution, specifically the allocation of natural resources rents from political and economic cores to the economic and geographical peripheries whence the resource originated. Based on a case study of the coal seam gas sector in Queensland's Surat Basin, this paper focuses on the operation of the Queensland State Government's regional development fund for mining and energy extraction-affected regions. Employing an environmental justice framework, we critically explore the operation of these funds in ostensibly helping constituent communities in becoming resilient to the worst effects of the 'staples trap'. Drawing on secondary demographic and housing data for the region, as well as primary information collected from key respondents from mid-2018 to early 2019, we show that funds were distributed across all of the local government areas, and allocated to projects and places primarily on a perceived economic needs basis. However, concerns were raised with the probity of the funds' administration. In terms of recognition justice, the participation of smaller and more remote towns and local Indigenous communities was hampered by their structural marginalisation. Procedurally, the funds were criticised for the lack of local consultation taken in the development and approval of projects. While spatially concentrated expenditure may be the most cost-effective use of public monies, we argue that grant application processes should be open, transparent and inclusive, and the outcomes cognisant of the developmental needs of smaller communities, together with the need to foster regional solidarity and coherence. [ABSTRACT FROM AUTHOR]

In Australia, coal seam gas (CSG) could help to meet growing demands for cleaner alternatives to coal, thus making it important for the energy transition. By developing such an industry, not only does an energy resource become available, but large water volumes are also extracted, especially in the first stages of production. The purpose of this paper is to analyze the impacts of a large-scale coal seam gas industry on the landscape. Specifically, the research intends to explore how coal seam gas has changed the landscape of the agricultural production area in Western Downs, Queensland. In this Australian State, the water associated with coal seam gas production is considered an asset and the legislation in force encourages beneficial use of such resources. Comparison of aerial pictures highlights how, in a short timeframe, the local rural landscape has changed considerably due the extensive development of unconventional gas resources. The coal seam gas industry has provided the host region with opportunities for local development, but the issue of the sustainability of these new mining and non-mining activities still needs to be properly addressed. • Coal seam gas-associated water is potentially a valuable commodity. • In Queensland, the coal seam gas development footprint is quite extensive. • Landscape changes are related both to gas and CSG-associated water extraction. • Unsteady amounts of CSG-associated water pose challenges to the agricultural sector. [ABSTRACT FROM AUTHOR]

In-flight measurements of atmospheric methane (CH 4(a)) and mass balance flux quantification studies can assist with verification and improvement in the UNFCCC National Inventory reported CH 4 emissions. In the Surat Basin gas fields, Queensland, Australia, coal seam gas (CSG) production and cattle farming are two of the major sources of CH 4 emissions into the atmosphere. Because of the rapid mixing of adjacent plumes within the convective boundary layer, spatially attributing CH 4(a) mole fraction readings to one or more emission sources is difficult. The primary aims of this study were to use the CH 4(a) isotopic composition (δ13 C CH4(a)) of in-flight atmospheric air (IFAA) samples to assess where the bottom–up (BU) inventory developed specifically for the region was well characterised and to identify gaps in the BU inventory (missing sources or over- and underestimated source categories). Secondary aims were to investigate whether IFAA samples collected downwind of predominantly similar inventory sources were useable for characterising the isotopic signature of CH 4 sources (δ13 C CH4(s)) and to identify mitigation opportunities. IFAA samples were collected between 100–350 m above ground level (m a.g.l.) over a 2-week period in September 2018. For each IFAA sample the 2 h back-trajectory footprint area was determined using the NOAA HYSPLIT atmospheric trajectory modelling application. IFAA samples were gathered into sets, where the 2 h upwind BU inventory had > 50 % attributable to a single predominant CH 4 source (CSG, grazing cattle, or cattle feedlots). Keeling models were globally fitted to these sets using multiple regression with shared parameters (background-air CH 4(b) and δ13 C CH4(b)). For IFAA samples collected from 250–350 m a.g.l. altitude, the best-fit δ13 C CH4(s) signatures compare well with the ground observation: CSG δ13 C CH4(s) of -55.4 ‰ (confidence interval (CI) 95 % ± 13.7 ‰) versus δ13 C CH4(s) of -56.7 ‰ to - 45.6 ‰; grazing cattle δ13 C CH4(s) of -60.5 ‰ (CI 95 % ± 15.6 ‰) versus - 61.7 ‰ to - 57.5 ‰. For cattle feedlots, the derived δ13 C CH4(s) (- 69.6 ‰, CI 95 % ± 22.6 ‰), was isotopically lighter than the ground-based study (δ13 C CH4(s) from -65.2 ‰ to -60.3 ‰) but within agreement given the large uncertainty for this source. For IFAA samples collected between 100–200 m a.g.l. the δ13 C CH4(s) signature for the CSG set (- 65.4 ‰, CI 95 % ± 13.3 ‰) was isotopically lighter than expected, suggesting a BU inventory knowledge gap or the need to extend the population statistics for CSG δ13 C CH4(s) signatures. For the 100–200 m a.g.l. set collected over grazing cattle districts the δ13 C CH4(s) signature (- 53.8 ‰, CI 95 % ± 17.4 ‰) was heavier than expected from the BU inventory. An isotopically light set had a low δ13 C CH4(s) signature of - 80.2 ‰ (CI 95 % ± 4.7 ‰). A CH 4 source with this low δ13 C CH4(s) signature has not been incorporated into existing BU inventories for the region. Possible sources include termites and CSG brine ponds. If the excess emissions are from the brine ponds, they can potentially be mitigated. It is concluded that in-flight atmospheric δ13 C CH4(a) measurements used in conjunction with endmember mixing modelling of CH 4 sources are powerful tools for BU inventory verification. [ABSTRACT FROM AUTHOR]

Concentrations of major ions in coal mine discharge waters and unconventional hydrocarbon produced waters derived from coal bed methane (CBM) production, are potentially harmful to freshwater ecosystems. Bicarbonate is a major constituent of produced waters from CBM and coal mining. However, little is known about the relative toxicity of differing ionic proportions, especially bicarbonate, found in these CBM waters. As all freshwater invertebrates tested are more acutely sensitive to sodium bicarbonate (NaHCO3) than sodium chloride (NaCl) or synthetic sea water, we tested the hypotheses that toxicity of CBM waters are driven by bicarbonate concentration, and waters containing a higher proportion of bicarbonate are more toxic to freshwater invertebrates than those with less bicarbonate. We compared the acute (96 h) lethal toxicity to six freshwater invertebrate species of NaHCO3 and two synthetic CBM waters, with ionic proportions representative of water from CBM wells across New South Wales (NSW) and Queensland (Qld), in Australia. The ranking of LC50 values expressed as total salinity was consistent with the hypotheses. However, when toxicity was expressed as bicarbonate concentration, the hypothesis that the toxicity of coal bed waters would be explained by bicarbonate concentration was not well supported, and other ionic components were either ameliorating or exacerbating the NaHCO3 toxicity. Our findings showed NaHCO3 was more toxic than NaCl and that the NaHCO3 proportion of synthetic CBM waters drives toxicity, however other ions are altering the toxicity of bicarbonate. [ABSTRACT FROM AUTHOR]

• Traffic offenses can predict a person's likelihood of being at fault for a crash. • Versatile offenders pose the highest risk to road safety. • People who drive while unlicensed are a particular group of concern. • People who commit serious, criminal-type, traffic offenses are at risk. Introduction: The aim of this study was to determine whether drivers who had received more traffic infringements were more likely to be at fault for the crash in which they were killed. Method: The current dataset was derived from the crash and traffic history records provided by the Queensland Department of Transport and Main Roads and Coroner's Court for every driver, with available records, who was killed in a crash in Queensland, Australia, between 2011 and 2019 (N = 1,136). The most common traffic offenses in the current sample were speeding, disobeying road rules, driving under the influence of drugs and alcohol, and unlicensed driving. Logistic regression models were used to compute odds ratios for the number of overall offenses, the number of specific offense types, and for specific offending profiles that were derived from the literature. Age, gender, and crash type were each controlled for by entering them into the initial blocks of the regression models. Results: After accounting for the variance associated with age, gender, and crash type, only the overall number of offenses and the number of unlicensed driving offenses predicted a significant change in a drivers' likelihood of being at fault for the crash that killed them. Furthermore, drivers who were identified as having versatile (i.e., multiple offenses from different categories) or criminal-type offense profiles (i.e., offenses that were considered to approximate criminal offenses) were each significantly more likely to be at fault for a fatal crash. Practical Applications: This study provided an important contribution by demonstrating how a more nuanced approach to understanding how a driver's traffic history might be used to identify drivers who are more at risk of being involved in a crash (i.e., for which they were at fault). The implications of these findings are discussed with recommendations and consideration for future research. [ABSTRACT FROM AUTHOR]

This work was supported by National Natural Science Foundation of China (No. 52172218) and the JST‐ERATO Materials Space‐Tectonics Project (JPMJER2003). Z.A. is grateful to the Researchers Supporting Project (RSP‐2021/1), King Saud University, Riyadh, Saudi Arabia. This work was performed in part at the Queensland node of the Australian National Fabrication Facility, a company established under the National Collaborative Research Infrastructure Strategy to provide nano and microfabrication facilities for Australia′s researchers. [ABSTRACT FROM AUTHOR]

Coal seam gas (CSG) accounts for about one-quarter of natural gas production in Australia and rapidly increasing amounts globally. This is the first study worldwide using airborne measurement techniques to quantify methane (CH4) emissions from a producing CSG field: the Surat Basin, Queensland, Australia. Spatially resolved CH4 emissions were quantified from all major sources based on top-down (TD) and bottom-up (BU) approaches, the latter using Australia's UNFCCC reporting workflow. Based on our TD-validated BU inventory, CSG sources emit about 0.4% of the produced gas, comparable to onshore dry gas fields in the USA and The Netherlands, but substantially smaller than in other onshore regions, especially those where oil is co-produced (wet gas). The CSG CH4 emission per unit of gas production determined in this study is two to three times higher than existing inventories for the region. Our results indicate that the BU emission factors for feedlots and grazing cattle need review, possibly requiring an increase for Queensland's conditions. In some subregions, the BU estimate for gathering and boosting stations is potentially too high. The results from our iterative BU inventory process, which feeds into TD data, illustrate how global characterization of CH4 emissions could be improved by incorporating empirical TD verification surveys into national reporting. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 1)'. [ABSTRACT FROM AUTHOR]

In regions where there are multiple sources of methane (CH4) in close proximity, it can be difficult to apportion the CH4 measured in the atmosphere to the appropriate sources. In the Surat Basin, Queensland, Australia, coal seam gas (CSG) developments are surrounded by cattle feedlots, grazing cattle, piggeries, coal mines, urban centres and natural sources of CH4. The characterization of carbon (δ13C) and hydrogen (δD) stable isotopic composition of CH4 can help distinguish between specific emitters of CH4. However, in Australia there is a paucity of data on the various isotopic signatures of the different source types. This research examines whether dual isotopic signatures of CH4 can be used to distinguish between sources of CH4 in the Surat Basin. We also highlight the benefits of sampling at nighttime. During two campaigns in 2018 and 2019, a mobile CH4 monitoring system was used to detect CH4 plumes. Sixteen plumes immediately downwind from known CH4 sources (or individual facilities) were sampled and analysed for their CH4 mole fraction and δ13CCH4 and δDCH4 signatures. The isotopic signatures of the CH4 sources were determined using the Keeling plot method. These new source signatures were then compared to values documented in reports and peer-reviewed journal articles. In the Surat Basin, CSG sources have δ13CCH4 signatures between -55.6 ‰ and -50.9 ‰ and δDCH4 signatures between -207.1 ‰ and -193.8 ‰. Emissions from an open-cut coal mine have δ13CCH4 and δDCH4 signatures of -60.0±0.6 ‰ and -209.7±1.8 ‰ respectively. Emissions from two ground seeps (abandoned coal exploration wells) have δ13CCH4 signatures of -59.9±0.3 ‰ and -60.5±0.2 ‰ and δDCH4 signatures of -185.0±3.1 ‰ and -190.2±1.4 ‰. A river seep had a δ13CCH4 signature of -61.2±1.4 ‰ and a δDCH4 signature of -225.1±2.9 ‰. Three dominant agricultural sources were analysed. The δ13CCH4 and δDCH4 signatures of a cattle feedlot are -62.9±1.3 ‰ and -310.5±4.6 ‰ respectively, grazing (pasture) cattle have δ13CCH4 and δDCH4 signatures of -59.7±1.0 ‰ and -290.5±3.1 ‰ respectively, and a piggery sampled had δ13CCH4 and δDCH4 signatures of -47.6±0.2 ‰ and -300.1±2.6 ‰ respectively, which reflects emissions from animal waste. An export abattoir (meat works and processing) had δ13CCH4 and δDCH4 signatures of -44.5±0.2 ‰ and -314.6±1.8 ‰ respectively. A plume from a wastewater treatment plant had δ13CCH4 and δDCH4 signatures of -47.6±0.2 ‰ and -177.3±2.3 ‰ respectively. In the Surat Basin, source attribution is possible when both δ13CCH4 and δDCH4 are measured for the key categories of CSG, cattle, waste from feedlots and piggeries, and water treatment plants. Under most field situations using δ13CCH4 alone will not enable clear source attribution. It is common in the Surat Basin for CSG and feedlot facilities to be co-located. Measurement of both δ13CCH4 and δDCH4 will assist in source apportionment where the plumes from two such sources are mixed. [ABSTRACT FROM AUTHOR]

Methane (CH 4) is a potent greenhouse gas and a key precursor of tropospheric ozone, itself a powerful greenhouse gas and air pollutant. Methane emissions across Queensland's Surat Basin, Australia, result from a mix of activities, including the production and processing of coal seam gas (CSG). We measured methane concentrations over 1.5 years from two monitoring stations established 80 km apart on either side of the main CSG belt located within a study area of 350 km × 350 km. Using an inverse modelling approach coupled with a bottom-up inventory, we quantify methane emissions from this area. The inventory suggests that the total emission is 173.2 × 10 6 kg CH 4 yr -1 , with grazing cattle contributing about half of that, cattle feedlots ∼ 25 %, and CSG processing ∼ 8 %. Using the inventory emissions in a forward regional transport model indicates that the above sources are significant contributors to methane at both monitors. However, the model underestimates approximately the highest 15 % of the observed methane concentrations, suggesting underestimated or missing emissions. An efficient regional Bayesian inverse model is developed, incorporating an hourly source–receptor relationship based on a backward-in-time configuration of the forward regional transport model, a posterior sampling scheme, and the hourly methane observations and a derived methane background. The inferred emissions obtained from one of the inverse model setups that uses a Gaussian prior whose averages are identical to the gridded bottom-up inventory emissions across the domain with an uncertainty of 3 % of the averages best describes the observed methane. Having only two stations is not adequate at sampling distant source areas of the study domain, and this necessitates a small prior uncertainty. This inverse setup yields a total emission of (165.8 ± 8.5) × 10 6 kg CH 4 yr -1 , slightly smaller than the inventory total. However, in a subdomain covering the CSG development areas, the inferred emissions are (63.6 ± 4.7) × 10 6 kg CH 4 yr -1 , 33 % larger than those from the inventory. We also infer seasonal variation of methane emissions and examine its correlation with climatological rainfall in the area. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Jurassic Walloon Coal Measures of the Surat Basin in eastern Australia host the continent's most significant coal bed methane resources. Previous studies have interpreted the Walloon Coal Measures within a single depositional facies model encompassing a wholly terrestrial setting. Using a multidisciplinary approach (facies analysis, palynology and wireline logs), the evolution of the Walloon Coal Measures is described within a new chronostratigraphic framework defined by accurate and precise U–Pb tuff dates. Analysis of sedimentary facies indicates that the majority of the Walloon Coal Measures was deposited by relatively small (<300 m wide), low gradient rivers on a poorly‐drained floodplain with numerous small lakes and mires. However, this study also identified some marine‐influenced facies with brackish palynomorphs (notably dinoflagellate cysts) and tidal sedimentary structures. These facies appear to have been deposited in estuaries during times of transgression. The evidence for base level shifts suggests that the coals may not have coevally accumulated with at least some of the thicker sandstones. Palaeogeographic maps for eleven time intervals suggest that rivers drained towards to the south/south‐west and south‐east, as indicated by sandstone percentage and gross unit isopach maps, presumably into proximal estuarine complexes. Marine incursions into the continent probably came from the north and east during times of high eustatic sea level and as precursors to those of the more persistent and extensive transgressions of the Early Cretaceous. A similar multidisciplinary approach should help to elucidate the evolution of other fluviolacustrine systems in other basins and aid in resource prediction. [ABSTRACT FROM AUTHOR]

This Article provides a glimpse into a living laboratory for the governance of the energy-water-food nexus. It does so to expand our understanding of nexus governance, which has remained under-examined in the context of unconventional gas development. Focusing on a case study of unconventional gas development in the state of Queensland in Australia, the Article explores governance innovations to manage this energy source's impact on water and food. The Article draws upon empirical data to identify a hybrid approach to nexus governance, involving a mix of four policy instruments, which each differently frames and responds to nexus challenges arising in this emerging governance space. Each instrument has strengths and weaknesses, which leads to the identification of at least two pathways for better governing nexus issues: (1) building governance hybrids that adapt existing approaches to ensure complementary policy responses to nexus issues; and (2) pursuing new holistic and collaborative governance systems that can navigate complex social, economic, and environmental problems. The aim is to further inform the governance debate on nexus issues, particularly in the context of unconventional gas, and its impacts on water and food. [ABSTRACT FROM AUTHOR]

This paper describes how social resistance emerged between 2010 and 2016, in response to coal seam gas (CSG) industry development in the Northern Rivers region of New South Wales, Australia. Social responses to existing and proposed coal seam gas developments led to the formation of a substantial social movement, for which events are conceptualised and structured using the Movement Action Plan (MAP) model. Moyer's (2001) MAP model describes eight main stages of social movements, from 'normal times', through to 'success' and 'continuing the struggle'. The model also provides a useful frame for describing the key roles required to achieve successful and broad social mobilisation, which is discussed in the Northern Rivers context. Growing from a small seed of discontent in the Western Downs region of South-East Queensland, this social movement ultimately led to broad scale social licence withdrawal for the coal seam gas industry in the Northern Rivers region. It also led to the creation of a broad and complex network of associations and social identities, extending well beyond the local region. The international growth of a social movement against the unconventional gas industry appears to be re-fuelling the momentum of the global environmental justice movement. This paper explores when and how the industry's social licence was withdrawn. There are important learnings from this case study that can inform government policy on ways to improve community engagement in land use planning, to avoid such extreme cases of social licence withdrawal in the future. [ABSTRACT FROM AUTHOR]

Background: There is some concern that coal seam gas mining may affect health and wellbeing through changes in social determinants such as living and working conditions, local economy and the environment. The onward impact of these conditions on health and wellbeing is often not monitored to the same degree as direct environmental health impacts in the mining context, but merits attention. This study reports on the findings from a recurrent theme that emerged from analysis of the qualitative component of a comprehensive Health Needs Assessment (HNA) conducted in regional Queensland: that health and wellbeing of communities was reportedly affected by nearby coal seam gas (CSG) development beyond direct environmental impacts.Methods: Qualitative analysis was initially completed using the Framework Method to explore key themes from 11 focus group discussions, 19 in-depth interviews, and 45 key informant interviews with health and wellbeing service providers and community members. A key theme emerged from the analysis that forms the basis of this paper. This study is part of a larger comprehensive HNA involving qualitative and quantitative data collection to explore the health and wellbeing needs of three communities living in proximity to CSG development in regional Queensland, Australia.Results: Communities faced social, economic and environmental impacts from the rapid growth of CSG development, which were perceived to have direct and indirect effects on individual lifestyle factors such as alcohol and drug abuse, family relationships, social capital and mental health; and community-level factors including social connectedness, civic engagement and trust.Conclusions: Outer regional communities discussed the effects of mining activity on the fabric of their town and community, whereas the inner regional community that had a longer history of industrial activity discussed the impacts on families and individual health and wellbeing. The findings from this study may inform future health service planning in regions affected by CSG in the development /construction phase and provide the mining sector in regional areas with evidence from which to develop social responsibility programs that encompass health, social, economic and environmental assessments that more accurately reflect the needs of the affected communities. [ABSTRACT FROM AUTHOR]

The development of the coal seam gas industry in Australia has led to the extraction of large volumes of relatively salty groundwater. Once treated, this coal seam water (CSW) is being made available for irrigation and it is an opportunity for landholders to increase the level and reliability of their agricultural production. This paper reviews the use of CSW and approaches to sustainable agriculture. The review suggests that, barring technical and economic constraints, re-injection of treated CSW into stressed agricultural aquifers may provide more equitable access to water and broader economic benefits than current location-specific irrigation schemes. [ABSTRACT FROM PUBLISHER]

New U-Pb detrital zircon ages from sandstones have been determined for the Walloon Coal Measures-Springbok Sandstone section of the Surat Basin. In the late Jurassic Surat Basin, there is a shift from relatively thick coal measures – the Walloon Coal Measures – consisting of laterally discontinuous coal-seam horizons intercalated with lithic sandstones and mudstones to an overlying coal-poor sandstone-dominated unit – the Springbok Sandstone – that is more laterally continuous. Across the basin, the contact between the two units varies from transitional to unconformable, and the sandstone becomes less lithic. The nature of the contact and the compositional variability of the sandstone across the basin have implications for predicting communication between gas production fields and potential aquifers in the Walloon Coal Measures and overlying Springbok Sandstone. This study tests whether detrital zircon age (LA-ICP-MS) populations from sandstones within these two units can identify provenance shifts and potential tectonic drivers for basin infill at this time. Detrital zircon ages of both units, informed by paleocurrent measurements showing a southerly flowing depositional system, suggest sediment was sourced from three distinct terranes: the Thomson Orogen in northeastern Queensland; Permian-Triassic granitic intrusions emplaced within the northeast New England Orogen during the Hunter-Bowen Orogeny accretion event; and an inferred but now eroded Jurassic magmatic-arc located along the eastern margin of Gondwana. Two major source-delivery systems, named here Western and Eastern Source systems, are recognized by distinct detrital zircon age populations in both formations in the northern Surat Basin. The Western Source of the Walloon Coal Measures delivered substantial Jurassic age zircons, with minor Pre-Cambrian input; the Eastern Source delivered substantial reworked Precambrian and lesser Jurassic zircons. In contrast, the Western Source of the Springbok Sandstone delivered substantial Jurassic and distinct Triassic zircons dated between ca 234 Ma and 224 Ma in the north-west, while the Eastern Source delivered more pronounced Pre-Cambrian input, with minor Jurassic and absent or minor age zircons in the northeast. Maximum depositional ages for the Springbok Sandstone are approximately 2 Ma younger in the northwestern than in the northeastern Surat Basin. The westward younging could be due to migration of the system and/or differential movement on the bounding faults. • New insights into spatial and lateral provenance shift between the Middle-Late Jurassic strata, northern Surat Basin. • Multiple fluvial depocenters identified in the northern Surat Basin using U-Pb detrital zircon geochronology. • Potential reactivation of fault system may have caused a provenance shift between the Middle-Late Jurassic strata in Surat Basin • The detrital age populations when combined with MDAs and published CA-TIMS reveal a younging trend from east to west. [ABSTRACT FROM AUTHOR]

Coal seam gas (CSG) production requires the extraction of large volumes of water. Discharges of the extracted water into the environment occur via authorised temporary permits or through accidental releases. The purpose of this study is to assess the risk to shallow groundwater aquifers from potential CSG water releases in Queensland, Australia. A GIS based methodology was used to identify vulnerable shallow aquifers by overlaying a series of risk factors, which increase the likelihood of flow from the ground surface into aquifers below. We identified where the vulnerable aquifers are located and estimate that about 10,000 people live in these areas. The GIS based exposure mapping approach applied here provides a useful „first-pass. assessment of areas with CSG activity. Areas identified as potentially high risk should be prioritised for further detailed investigation. [ABSTRACT FROM AUTHOR]

The Late Jurassic Walloon Subgroup (recently dated as Oxfordian) is a productive, subbituminous coal seam gas source in the Surat Basin and can be subdivided from bottom to top into the Taroom Coal Measures, the Tangalooma Sandstone, the Lower and Upper Juandah Coal Measures, which have different coal character. The lower Taroom coals are commonly thick, associated with sandstones and interpreted to form as base level is rising, creating sodden anoxic conditions for peat accumulation. The middle Tangalooma to Lower Juandah contains fewer and thinner coals, and transitions upwards from a sandstone to siltstone dominated sequence responding to inundation with the development of floodplain lakes. The strata then coarsen upward in both grain size and coal thickness in the Upper Juandah Coal Measures, which may be eroded by an overlying unit, the Springbok Sandstone. This unconformable surface is basin wide and depending on age, can be tied into global changes in climate and base level. Existing models for peat growth under changing base level and the variability in terms of the conditions of peat formation through time, as well as throughout the basin, are tested. Environment of peat deposition and changes therein, are investigated by petrographic analysis of the Walloon coals, coupled with high resolution lithotype logging of core and organic stable carbon isotope analysis. Fine microlayering and abundance of root suberinite, telo- and detrovitrinite indicate precursory peat formation in a mostly herbaceous marsh to fen environment, in which bigger trees are either infrequent or absent, except for the lower seams of the Taroom Coal Measures and the upper seams of the Lower Juandah Coal Measures, where bright bands are thicker (≥ 10 mm) and more frequent. No extended periods of dehydration-oxidation (< 1 vol.% mmf inertinite group macerals) are indicated until the deposition of the Upper Juandah Coal Measures that contain greater amounts (5 to 15 vol.% mmf with rare 68 vol.%) of inertinite group macerals. Suberinite is interpreted to reflect dense root mats that are resistant to decay by microbial activity. They leave behind their suberinised exoderms, which originally helped wetland plants to protect themselves from deleterious solutes or in case of a change to drier conditions provided protection from desiccation. The most common inertinite maceral found in the Upper Juandah Coal Measures is inertodetrinite, associated with detrovitrinite. After bush or swamp fires, pieces of charcoal on dried out peat surfaces are easily blown away by the wind and accumulate with sediment in standing water. Fusinites and semifusinites are mainly associated with telovitrinites and are likely to be the result of desiccation and (fungal) mouldering in addition to fire. Stable carbon isotopes of coal show a distinct positive shift in the Lower Juandah Coal Measures that sets in well before the increased inertinite content in the Upper Juandah Coal Measures. The enrichment in 13 C could be linked to a change in climate during the high stand depositional cycle, marking the onset of late stage falling, where base level begins to drop, later creating exposures and water stress. A shift to a less humid climate in the Upper Juandah Coal Measures could have favoured the conditions for desiccation, mouldering and bush fires, which is reflected in the coal's maceral composition. The Surat Basin δ 13 C isotope trend follows the global trend found in marine carbonate samples from the same age interval that corroborates increasing enrichment towards the top of the coal measures (approximately middle Oxfordian), followed by a shift to more negative compositions, which corresponds to the onset of the Springbok Sandstone deposition on an unconformable surface. [ABSTRACT FROM AUTHOR]

Particulate matter (PM) or particle pollution include the tiny particles of dust and fly ash particles are expelled from coal-burning power plants. Coal combustion is an extremely prevalent source of air pollution, and resulting PM has substantial impacts on human health, especially in industrial zones. This paper aims to design a novel hybrid deep learning framework based on long short-term memory (LSTM) integrated with a two-stage data filtering technique to accurately predict the air quality indices (i.e., PM 2.5 and PM 10) in a chosen study region 'Miles Airport, Queensland,' that meets the needs of the coal seam gas industry in Australia. The data used to construct the novel hybrid two-stage data filtering technique based on LSTM comprising of six meteorological parameters (i.e., wind direction, wind speed, air temperature, relative humidity, solar radiation, and rainfall) and two environmental factors (i.e., ozone and total suspended particulate). In the first stage, two robust feature selection methods, namely, extreme gradient boosting (XGBoost) and the classification and regression tree (CART) approach, were adopted to explore the most significant predictors. Then in the second stage, the best subset regression (BSR) technique is utilized to determine the best subsets input combinations i.e., C1, C2, and C3 based on several particular metrics. The three BSR-based input combinations were employed in the LSTM model to estimate the PM 2.5 and PM 10. Furthermore, to validate the main hybrid framework, two advanced machine learning (ML) methods (i.e., LightGBM and ridge kernel regression (KRR)) and two traditional ML methods (i.e., Adaptive neuro-fuzzy inference system (ANFIS) and multilayer perceptron neural network (MLP)) were hybridized with the multi-level data filtering strategy by examining the optimal input combinations. Several statistical metrics, graphical tools, and diagnostic analyses evaluated the hybrid models. The outcomes of the PM 2.5 simulation based on 2375 data samples showed that the LSTM-C3 containing all the selected predictors yielded the most promising accuracy, followed by the LightGBM-C3 and MLP-C3 models. On the other hand, the simulation of PM 10 distribution demonstrated that the LSTM-C3 was superior to other models, followed by the KRR-C3 and LightGBM-C3 models. [ABSTRACT FROM AUTHOR]

Despite more than a decade of intensive coal seam gas exploration and development in the Surat Basin, fundamental aspects surrounding the sedimentary organisation of the Walloon Subgroup remain unresolved. While generally agreed to have been deposited on a waterlogged alluvial plain, contradictory paleogeographic models describe the Walloon Subgroup as an internally draining fluvio-lacustrine system or, alternatively, as a southeast-prograding distributive trunk drainage system. The former invokes a radially organised fluvial catchment feeding a basin depocentre, suggesting that rivers within the study area flowed from east to west. In contrast, a prograding trunk drainage system assumes an axial system flowing southeastward towards a distant paleocoastline. Without a unifying conceptual model describing the organisation of the Jurassic depositional system, predictions about the distribution of alluvial subenvironments within the Surat Basin are difficult. This study tests previous hypotheses surrounding the Walloon Subgroup's sedimentary organisation by reconstructing regional variations in alluvial architecture, fluvial styles and sediment dispersal patterns. The workflow integrates borehole image log interpretation, wireline log analysis, core description and numerical modelling to explore the character and occurrence of subenvironments throughout the basin. Synthesis of interpretations suggests a composite meandering to anastomosing fluvial system containing both a south-oriented trunk drainage component and tributary rivers feeding the axial system from the east. [ABSTRACT FROM AUTHOR]

Since the late 1990s, coalbed methane (CBM) has grown to be a significant part of the economy of the State of Queensland, Australia, building alongside world-scale coal-export operations. Environmental regulation in Queensland over the same period has evolved, with petroleum activities following a unified mineral rights/land tenure and environmental permitting process, particularly in respect to the impacts related to the spatial extent of CBM-basin developments. Following the announcements in 2008 of a number of multibillion-dollar liquefied-natural-gas-export projects, with industry estimates approaching 30,000 wells, attention by interest groups and the public at large gave rise to increased scrutiny by regulators of the scope of prevailing rules. In respect to the application of hydraulic fracturing, the CBM-sector has indicated a likelihood of fracturing up to 40% of wells. A number of shale resources and tight gas basins are also under exploration in Queensland, with horizontal completions. Thus, the State can expect a significant rise in the application of stimulation technology. The unconventional-resources sector in Australia is somewhat different from that in North America, with the absence of a third-party pipeline sector, the result being few major producers with their own pipeline networks and speculative minors. As a result of this industry structure of relatively few operators, permitting has been project-based rather than sector-based, resulting in older approvals having conditions inconsistent with modern expectations. The State Government has moved to amend this position by developing more-performance-focused codes in respect to new hydraulic-fracturing programs. It has also moved toward greater emphasis on compliance activities. This paper examines a wide range of environmental issues related to hydraulic fracturing, including those potentially affecting groundwaters, surface waters, landforms and geology, biodiversity, the atmosphere, and community, drawing examples from Queensland and elsewhere. In respect to environmental regulation of hydraulic fracturing, a single, risk-based comprehensive code is proposed that encompasses the use of stimulation across all energy sources and fluid systems--conventional oil and gas, CBM, unconventional oil and gas, and geothermal. Fundamental to the approach is a comprehensive risk assessment, considering a wide range of issues at local and regional scales. Permit conditions will target pre-event disclosure requirements, engineering constraints, environmental-protection measures, product accreditation, process monitoring, and post-event reporting. Disclosure of products is required under petroleum and gas legislation, but this new approach will require product accreditation under an international standard that encompasses contaminant-concentration limits, human toxicology, and ecotoxicology. Evidence supporting code development includes consideration of environmental issues in Queensland, detailed review of hydraulic-fracturing studies, and reviews of petroleum-engineering risks. A detailed legislative review was completed that considers rules from 55 jurisdictions (including Australia, the US, Canada, Brazil, the UK and Scotland, France, and South Africa) across 59 identified regulatory matters. The following general principles and practices have been proposed to underpin the revised code to minimize the likelihood of adverse impacts from hydraulic fracturing: * Detailed understanding of the local stratigraphy, including aquifers, faults, linear features, hydraulic conductivity, porosity, seismic risk, and groundwater-dependent assets * Detailed engineering understanding of the impacts of applied stresses, including aquifer drawdown, on connectivity to aquifers above and below the fractured zone subsequent to the hydraulic-fracturing activity * To require the presence of vertically impermeable formations between the fractured zone and other aquifers * To require installation of a multibarrier casing string that isolates aquifers from hydrocarbon-bearing formations and, with current certification, demonstrates internal and external mechanical integrity * To ensure injected fluids have low toxicity, contain no persistent bioaccumulating constituents, and are accredited for use under an international standard * For the operator to apply advanced process control that incorporates real-time analysis, fracture modeling, and formation understanding by use of techniques such as microseismic measurements, as required, to assist in the early development of the resource and to address identified environmental risk over the life of the project * To initiate and maintain a high level of meaningful communication with adjacent groundwater users, near neighbors, government, and the public in general This paper presents information supporting the chain of evidence leading to a revision of the Queensland regulations that is expected to be completed and approved in 2015, following industry and public consultation. [ABSTRACT FROM AUTHOR]

Queensland experienced extraordinary growth in booked 2P coal seam gas ( CSG) reserves, rising from 3,400 PJ in 2005 to 41,200 PJ in 2013. Given annual domestic consumption of ca. 700 PJ/a, 2P reserves rapidly shifted from 14 to 72 years supply. Profit-maximising firms sought to speed up commercialisation of reserves through the development of three liquefied natural gas ( LNG) export plants at Gladstone. In this article, we present forecasts of Australia's east coast interconnected gas system with daily resolution using our dynamic partial equilibrium model. Modelling results show the rapid development of LNG plants combined with restrictive CSG development policies in NSW may result in unserved load from 2016. Relaxing development constraints or delaying construction of one LNG terminal by 1 year could have avoided the risk of Unserved Load events in the domestic gas market. Lessons can be learned from this CSG- LNG boom scenario. Facilitating new gas supplies is the most efficient way of alleviating the impacts of the CSG- LNG boom on domestic markets in the medium term. In the long-term, Australian policymakers may consider the merits of a National Net Benefits Test to maximise welfare through appropriate coordination - as is done by policymakers in the USA - as opposed to protecting local industries through 'domestic gas reservation policies'. [ABSTRACT FROM AUTHOR]

The sustainable in situ regeneration of microbial (biogenic) methane or microbially enhanced coal bed methane (‘MECoM’) is an emerging concept being investigated globally. Promising results and recommendations of a preliminary culture study of Walloon Subgroup co-produced coal seam gas (CSG) waters from the Surat Basin, Queensland established the presence of viable methanogens and suggested that in situ methanogenesis could be stimulated using physical and chemical reservoir treatments. This paper represents the culmination of a stepwise basin analysis project ultimately aimed at siting potential in situ bioreactor locations in the eastern Surat Basin. The integration of stratigraphically located data on the molecular and isotopic composition of desorbed gases, host coal properties and spatially associated waters through the core production zone has allowed the spatial variability and relative influence of hydro-geological factors on methanogenesis to be evaluated in detail for the first time. Higher gas contents and systematically enriched CH 4 and CO 2 carbon isotopic compositions in the stratigraphically central coal seams (oldest-youngest: in the upper Taroom Coal Measures, Tangalooma Sandstone lower Juandah Coal Measures) are best explained by increased rates of microbial CO 2 reduction and substrate depletion. There is a building case to trial MECoM in the central coal seams in a depleted/underperforming well in an area of high permeability. Integrated microbiological, chemical engineering, hydro-chemical and geological studies are ongoing to further enhance understanding of Walloon Subgroup CSG and the bioreactor potential of the Surat Basin. [ABSTRACT FROM AUTHOR]

The Middle Jurassic Walloon Subgroup is a prolific coal seam gas (CSG) resource in the Surat Basin, Queensland. Sedimentary framework models constrain stochastic reservoir models of the geological heterogeneity, but there is limited basin analysis information in the public domain. Here we present a regionally consistent stratigraphic framework model for the Walloon CSG play in the eastern Surat Basin. Lithostratigraphic correlation of open-file industry and government wireline logs supports the interpretation of six subunits in the eastern Surat Basin (oldest–youngest: Durabilla Formation; Taroom Coal Measures; Tangalooma Sandstone; and Juandah Coal Measures, informally divided into three members named the lower Juandah Coal Measures, Juandah sandstone and upper Juandah Coal Measures). Important findings are that subunits within the Walloon Subgroup do not correlate along the entire CSG play area; in many places, the overlying Springbok Sandstone (Upper Jurassic) has incised to the lower Juandah Coal Measures level, removing the upper coal seam groups. The Walloon Subgroup thins to the south through a combination of depositional thinning and truncation. Lithofacies analysis and isopach maps support deposition in a southerly prograding fluvial system or clastic wedge. This stratigraphic and depositional interpretation informs models for hydrogeological studies of the Walloon Subgroup and underpins a regional assessment of controls on microbial methane distribution. [ABSTRACT FROM AUTHOR]

An introduction is presented is presented in which the editor discusses various reports within the issue on topics including practicalities of on-ground management, perception of stakeholder on environmental risk in the context of coal seam gas development in Queensland, and awards.

Social opposition to coal seam gas development in Queensland, Australia, reflects a broad and complex array of value-based issues, many of which are poorly represented in the regulatory decision-making process. The Queensland Government's adaptive policy framework for managing coal seam gas development has targeted risks identified through conventional risk management methodologies based solely on technical assessment. This study presents a novel approach to identifying risks during policy development. Socially perceived risks and policy gaps identified in news media are compared against existing policy using a three-phase mixed methodology. Three leverage points for strengthening the current management framework are proposed: (1) integration of policies to address cumulative and overlapping risks; (2) adoption of a prescribed development plan, allowing proactive data collection and impact assessment; and (3) establishment of a detailed, systematic approach for formulating and implementing adaptive policy measures. [ABSTRACT FROM AUTHOR]

Organic compounds in Australian coal seam gas produced water (CSG water) are poorly understood despite their environmental contamination potential. In this study, the presence of some organic substances is identified from government-held CSG water-quality data from the Bowen and Surat Basins, Queensland. These records revealed the presence of polycyclic aromatic hydrocarbons (PAHs) in 27% of samples of CSG water from the Walloon Coal Measures at concentrations <1 µg/L, and it is likely these compounds leached from in situ coals. PAHs identified from wells include naphthalene, phenanthrene, chrysene and dibenz[a,h]anthracene. In addition, the likelihood of coal-derived organic compounds leaching to groundwater is assessed by undertaking toxicity leaching experiments using coal rank and water chemistry as variables. These tests suggest higher molecular weight PAHs (including benzo[a]pyrene) leach from higher rank coals, whereas lower molecular weight PAHs leach at greater concentrations from lower rank coal. Some of the identified organic compounds have carcinogenic or health risk potential, but they are unlikely to be acutely toxic at the observed concentrations which are almost negligible (largely due to the hydrophobicity of such compounds). Hence, this study will be useful to practitioners assessing CSG water related environmental and health risk. [ABSTRACT FROM AUTHOR]

The article presents an analysis on the regulation of land access for resource development based on a coal seam gas case study from Queensland. It emphasizes the statutory agreements that bind upon successors and assigns of the landowner in reference to the provisions of Queensland's Petroleum and Gas Act 2004 which do not require recorded agreement on the land title. It presents recommendations for land access agreements addressing the nonconformity to the established legal rules.

Abstract: The Middle Jurassic Walloon Subgroup is a prolific, low-rank coal seam gas (CSG) resource in the Surat Basin, Australia. This study applied a regionally consistent stratigraphic framework model to open-file gas desorption and coal property data from 69 cored CSG wells, to assess spatial trends in gas content and test the influence of large-scale geological heterogeneity on present-day gas distribution. Continued successful exploration and production, and possible future microbial regeneration of the Walloon CSG resource require an improved understanding of the controls on gas content distribution across the core region of production in the eastern Surat Basin. The Walloon Subgroup can be subdivided into upper (Juandah) and lower (Taroom) coal measures separated by a relatively coal-barren and sandstone-dominated unit (Tangalooma Sandstone). Within these units, lateral variation in coal character is high, precluding a regionally agreed coal group or seam correlation. While the total dataset shows a general increase in gas content (dry-ash-free; d.a.f.) with increasing depth, as a function of hydrostatic pressure, there is considerable scatter in the distribution. Within individual wells, gas content follows one of three trends. Gas content either (1) increases; (2) increases, then decreases; or (3) decreases with depth. Trend 2 (parabolic) wells predominate, with the gas content maxima coinciding with the Tangalooma Sandstone, regardless of depth. As such, gas content layering follows, rather than cross-cuts the stratigraphy in the majority of wells. The change in gas content with depth between the different units and the wells was used to identify domains of different gas gradients, which could relate to differing gas saturations and geological setting. The well profiles and gas gradients were analysed against available open-file coal quality data, without strong correlation to rank or type parameters. The majority of very high gas gradient values occur in coals within or above the Tangalooma Sandstone, suggesting that it forms a regional-scale barrier, both to possible gas migration from underlying and higher rank coals, and to meteoric and biogenic recharge from above. Increased ethane values in the upper Taroom and Tangalooma CSG support this interpretation. Alternatively, this distribution may be the result of alternating adsorption–desorption cycles linked to burial and uplift. The wells containing the highest mean gas gradients span a range of subtle rank and structural domains, but generally occur in structural highs under topographic lows with hydrostatic head. Wells from smaller-scale anticlines not associated with topographic surface lows mainly exhibit lower mean gas gradients. The study significantly expands the number of published gas content trends and proposes several factors influencing their formation and geographical distribution. The results form the basis for future targeted sampling to test for gas origins, migration, retention and biogenic recharge processes within the Surat Basin. [Copyright &y& Elsevier]

Abstract: Matrix shrinkage in coal-seam gas reservoirs as a result of production, and the resultant impact on absolute permeability, is a current area of intense interest. A number of publications have documented the existence of this phenomenon. The exponential growth behaviour of coal seam permeability with reservoir pressure depletion has been observed previously at the Fairway wells in the San Juan basin. More recently, an exponential trend has also been confirmed for a group of 10 wells in a region northeast of Fairway. An increase in the absolute permeability of coal seam is a result of matrix shrinkage caused by gas desorption, which becomes a dominant factor on cleat permeability over the effective horizontal stress change during production. Bottom hole pressure recovery during shut-in periods can provide valuable data concerning the impact of coal seam gas production on reservoir permeability. Arrow Energy''s historical production data, from the MGP field in the Bowen Basin, contains over 60 instances of data on pressure recovery during shut-in. These time lapse build-up periods have been analysed using the pseudo-pressure method (Kamal and Six, 1991) in an effort to gain an understanding of the extent and effect of this phenomenon within the company''s existing assets. The method is based on a pseudo pressure function that uses the adsorption isotherm and the relative permeability relations of the reservoir. The infinite acting radial flow regime was identified and the gradient was recorded on a semi log plot of the pseudo pressure versus dimensionless time. Results from these tests show multi fold increase in absolute permeability as a function of the estimated reservoir pressure. [Copyright &y& Elsevier]

Abstract: Produced water samples collected from Surat Basin coal seams in eastern Queensland, Australia were shown to contain viable microbial consortia with the ability to convert native Walloon coal into methane. Methane generation rates of up to 1.0m3/tcoal/day (30scf/ton/day) were observed, with overall yields up to 6.5m3/t coal (210scf/ton); in comparison, total methane reserves for the Surat Basin are typically 4 to 8m3/t. This is the first direct evidence of real-time biogenic coal-to-methane potential for an Australian coal seam sample. Six of the eight Surat Basin water samples tested positive for biomethane production when H2–CO2 was provided as the sole methanogenic substrate; five produced methane from methanol, but acetoclastic methanogenesis was not observed. An active H2–CO2 pathway could have implications for the conversion of sequestered CO2, if an in-situ source of reduced hydrogen is present in excess. In a simple experiment, biomethane production from a Walloon coal was not enhanced when the bicarbonate concentration in the medium was doubled. It is anticipated that the low surface area/solubility of coals may limit their bioavailability; coal-to-methane rates and final yields increased in proportion to the coal particle surface area. Similarly, when a Zonyl FSN surfactant was added to improve coal bioavailability, the initial methane production rate increased by 240%, and the final methane yield increased by 180% in comparison to a no-surfactant control. Overall, these results suggest an opportunity to enhance Surat Basin coalbed methane reserves via in-situ stimulation of indigenous microbial consortia. [Copyright &y& Elsevier]

Abstract: This paper describes the methodology used to derive the economics of CO2 storage in coal with enhanced coalbed methane recovery. A significant difference between CO2 storage in coal seams and storage in saline aquifers is that the incrementally recovered natural gas constitutes an additional revenue stream. In the case of CO2 storage in coal it is necessary to distinguish between CBM (primary coalbed methane recovery), CO2-ECBM (enhanced coalbed methane recovery caused by and including the injection of CO2), and CO2 storage with incremental CBM recovery (Storage-ICBM). The methodology is demonstrated by means of a case study that evaluates the economics of carbon capture and storage with incremental CBM recovery (CCS-ICBM) at the Spring Gully CBM prospect in the Bowen Basin, QLD, Australia–Australia’s most productive CBM basin. Economic analyses of the Spring Gully development show that the specific cost of CO2-ECBM is A$37/t CO2 avoided (equivalent to US$31/t at an assumed long term exchange rate of A$1.00 = US$0.85) including capture costs. However, this incorporates the benefits of the underlying CBM project and therefore underestimates the cost of CCS-ICBM. The incremental cost of CCS-ICBM is A$92/t (US$78/t) excluding these benefits. The results demonstrate the importance of using an appropriate methodology to determine and present storage economics. If no distinction between CO2-ECBM and Storage-ICBM is made, the real costs of storage will for most cases be significantly underestimated and could potentially lead to poor investment decisions and the selection of economically unviable storage sites. [Copyright &y& Elsevier]

Abstract: Thirty six onshore basins in Queensland, Australia, have been assessed for their CO2 geological storage prospectivity through injection into either: regional reservoir-seal intervals (‘saline reservoirs‘ and aquifers); depleted oil and gas fields; or deep unmineable coal seams. This comprehensive state wide regional assessment is based on the technical (geological) suitability for geological storage, and does not consider factors such as potential interference with other resources, distance from emissions nodes or absolute storage volumes. Basins were assessed by evaluating the potential reservoir-seal intervals for their effectiveness for injection, storage and containment of CO2. Methodologies have been developed that allow the estimation of storage capacity volumes within highly prospective reservoir-seal fairways at a regional scale. These estimates reflect conservative values that are more reliable than previous theoretical estimates, which relied upon access to pore space at the physical limit of the pore rock volume to accept fluids. Results show that the greatest potential to store the large quantities of CO2 required to make deep cuts in Queensland’s stationary emissions is to use deep, regional reservoir-seal intervals using structural traps or migration assisted storage (MAS) mechanisms. The Bowen, Cooper, Eromanga, Galilee and Surat basins contain Paleozoic–Mesozoic age fluvial reservoirs that have either produced hydrocarbons, and/or are major aquifers, and are evaluated as having the highest prospectivity for CO2 geological storage in Queensland. Other basins have either low prospectivity or are unsuitable for geological storage. Depleted oil and gas fields and deep unmineable coal seams provide only limited opportunities for geological storage of CO2 in Queensland. [Copyright &y& Elsevier]

Abstract: Coal bed methane (CBM) is a significant growing industry in Queensland''s energy sector. It is, however, a relatively new industry with little local water quality data and stable isotope compositions of production waters and gases available in the public domain. This study aims to determine whether water quality and stable isotope data can be correlated with gas and groundwater production and flow pathways, and identify zones of recharge and water mixing. Stable isotope analysis and accessory water quality tests were conducted on CBM production gas and water samples collected from two CBM producing bituminous coal seams within a single field in the Bowen Basin. In the production field, the reservoir seams are gently folded with eastwardly dipping fold axes, and compartmentalised by an ENE normal fault on the flank of a broad central anticline that contains minor faults. For one seam, splitting and a change in coal quality parallels the fault and fold axes. Although virgin reservoir conditions were similar, differing production performance north and south of the main fault suggests it acts as a barrier to water and gas flow along strike. The stable isotope analysis on the production water showed that waters with more positive δD and δ 18O compositions were associated with areas of higher water production and shallower depths, whereas more negative δD and δ 18O compositions were associated with lower water production and high gas production. The gas isotope analysis showed that production gases had both biogenic and thermogenic origins and that secondary biogenic gas generated through CO2 reduction comprises a significant portion of the CBM produced from this field. More negative CH4 δ 13C values characterize the zones of meteoric recharge in shallow, up-dip areas. Gas production data and CO2 δ 13C values suggest that this may result from 13CH4 stripping by the recharge waters and/or increased biogenic activity in this area. Smaller CO2–CH4 carbon isotopic fractionation values characterized zones of meteoric recharge, whereas higher isotopic fractionation values characterized the high gas production domain. [Copyright &y& Elsevier]

The article details a study which investigated the kinetics of binary gas displacement and Darcy flow in coal using Maxwell-Stefan (MS) diffusion theory. The study was conducted to understand the carbon dioxide (CO2)-sequestration enhanced coalbed methane (ECBM) recovery process. The bulk of coal used in the study was taken from a Bowen Basin coal mine located in Queensland. The study concluded that MS diffusion theory is best for describing diffusion of mixed gases in coals. Findings of the study are said to be of significance to modeling ternary gas mixtures in ECBM production.