Hydrologic properties of coal beds in the Powder River Basin, Montana I. Geophysical log analysis

Morin, Roger H.

doi:10.1016/j.jhydrol.2004.11.006

Cited by 27 publications

(6 citation statements)

References 27 publications

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“…However, in this study, the normal borehole fluid was turbid. This implies that the boreholes must be treated to have a transparent fluid, as stated by Morin (2005), or should be dry (aired). Thus, it became necessary to add a flocculant (aluminum sulfate) several hours before the commencement of geophysical logging.…”

Section: Execution Methods Adopted For Data Collectionmentioning

confidence: 99%

Comparative Analyses of Geophysical Logs of Resistivity as Applied to Coal Deposits

et al. 2018

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ABSTRACT. This study compares data sets obtained from three geophysical probes used for measuring rock resistivity. A detailed analysis was carried out to determine which of these probes provides the best option in terms of identification of coal-seam thickness. The resistivity probes used were guard log (GL), single-point resistance (SPR), and induction log (IND) probes. To aid the comparison among the different logs, two other geophysical logs were included: natural gamma (NG) and optical televiewer (OPTV), which helped to identify the coal seams. In the specific case of OPTV, when the situation is favorable, it identifies the coal seams and checks the vertical resolution of the other logs due to its excellent vertical resolution. In this study, analyzed data were obtained from four different coal deposits, namely B3, Calombo, Cerro, and Seival. All the coal deposits mentioned are located in the state of Rio Grande do Sul, Brazil. In all, 13 boreholes with recovered core samples are presented and discussed. The geological descriptions of the 13 boreholes are the main information used as a control parameter in comparisons with the geophysical logs, while OPTV images served as an alternative to verify the vertical resolution of the logs. At the end of the analysis, it was found that the guard log probe tends to offer better performance in the aspect of lithological identification, demonstrating a greater capacity in comparison with the others in terms of vertical resolution. Statistically, it presented the closest estimated value of coal-seam thickness in relation to that provided by geological description of the recovered core samples. Keywords: geophysics, coal, resistivity, OPTV. RESUMO. Este estudo compara registros de perfilagem geofísica obtidos por três sondas que medem a resistividade de litologias. Uma análise detalhada foi feita para determinar qual destas sondas proporciona a melhor opção em termos da identificação de espessuras de camadas de carvão. As sondas de resistividade utilizadas foram: guard log , single point resistance e induction log. Para auxiliar na comparação entre as diferentes sondas, outros dois registros geofísicos foram incluídos: radiação gama natural e optical televiewer (OPTV), os quais ajudaram a identificar os estratos de carvão. No caso específico do OPTV, quando a situação é favorável, ele permite identificar os estratos de carvão e verificar a resolução vertical dos demais registros, em função da excelente resolução vertical. Neste estudo, foram analisados dados obtidos em 4 depósitos de carvão diferentes: B3, Calombo, Cerro e Seival. Todos os depósitos de carvão mencionados situam-se no estado do Rio Grande do Sul – Brasil. Ao todo, 13 furos de sondagem com recuperação de testemunhos são apresentados e discutidos. As descrições geológicas dos 13 furos de sondagem são as informações principais utilizadas como parâmetro de controle nas comparações entre os perfis geofísicos, enquanto que as imagens OPTV serviram como uma alternativa para verificar a resolução vertical dos perfis geofísicos. Ao final das análises, verificou-se que o dispositivo guard log tende a ter o melhor desempenho no aspecto de identificação litológica, demonstrando uma capacidade superior em relação aos demais arranjos em termos de resolução vertical. Estatisticamente, ele apresentou as estimativas de espessurasmais próximas em valor, em relação às espessuras proporcionadas pelas descrições geológicas de testemunhos de sondagem.Palavras-chave: geofísica, carvão, resistividade, OPTV.

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Section: Execution Methods Adopted For Data Collectionmentioning

confidence: 99%

Comparative Analyses of Geophysical Logs of Resistivity as Applied to Coal Deposits

et al. 2018

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“…Understanding of groundwater flows between aquifers can be more complex due to anisotropic hydraulic conductivity. Interpretation of geophysical well logs analysis in the coal seam aquifer from the Powder River Basin, SE Montana, showed isotropic horizontal groundwater flows in coals due to the bedding configuration (Morin 2003).…”

Section: Does Underground Release Contaminate Drinking Water Aquifers?mentioning

confidence: 97%

Coal seam gas water: potential hazards and exposure pathways in Queensland

Navi

Skelly²,

Taulis

et al. 2014

International Journal of Environmental Health Research

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The extraction of coal seam gas (CSG) produces large volumes of potentially contaminated water. It has raised concerns about the environmental health impacts of the co-produced CSG water. In this paper, we review CSG water contaminants and their potential health effects in the context of exposure pathways in Queensland's CSG basins. The hazardous substances associated with CSG water in Queensland include fluoride, boron, lead and benzene. The exposure pathways for CSG water are (1) water used for municipal purposes; (2) recreational water activities in rivers; (3) occupational exposures; (4) water extracted from contaminated aquifers; and (5) indirect exposure through the food chain. We recommend mapping of exposure pathways into communities in CSG regions to determine the potentially exposed populations in Queensland. Future efforts to monitor chemicals of concern and consolidate them into a central database will build the necessary capability to undertake a much needed environmental health impact assessment.

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“…In a natural setting, coal seam gas is entrapped in the coal seams under high pressure. In order to release the gas, groundwater is often extracted from the coal bed to lower the hydraulic pressure in the coal (Morin, ). This could affect the groundwater resources in the GAB aquifers due to leakage through the BCB.…”

Section: Application To the Betts Creek Bedsmentioning

confidence: 99%

Application of 1D paleo‐fluvial process modelling at a basin scale to augment sparse borehole data: example of a Permian formation in the Galilee Basin, Australia

Jiang

Mariethoz

Raiber

et al. 2015

Hydrological Processes

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The heterogeneous hydraulic conductivity (K) in water‐bearing formations controls subsurface flow and solute transport processes. Geostatistical techniques are often employed to characterize the K distribution in space based on the correlation between K measurements. However, at the basin scale, there are often insufficient measurements for inferring the spatial correlation. This is a widespread problem that we address in this study using the example of the Betts Creek Beds (BCB) in the Galilee Basin, Australia. To address the lack of data, we use a 1D stochastic fluvial process‐based model (SFPM) to quantify the total sediment thickness, Z(x), and the sandstone proportion over the total thickness, Ps(x), in the BCB. The semivariograms of Z(x) and Ps(x) are then extracted and used in sequential Gaussian simulation to construct the 2D spatial distribution of Z(x) and Ps(x). Ps(x) can be converted to a K distribution based on classical averaging methods. The results demonstrate that the combination of SFPM and geostatistical simulation allows for the evaluation of upscaled K distribution with a limited number of K measurements. Copyright © 2015 John Wiley & Sons, Ltd.

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Hydrologic properties of coal beds in the Powder River Basin, Montana I. Geophysical log analysis

Cited by 27 publications

References 27 publications

Comparative Analyses of Geophysical Logs of Resistivity as Applied to Coal Deposits

Comparative Analyses of Geophysical Logs of Resistivity as Applied to Coal Deposits

Coal seam gas water: potential hazards and exposure pathways in Queensland

Application of 1D paleo‐fluvial process modelling at a basin scale to augment sparse borehole data: example of a Permian formation in the Galilee Basin, Australia

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