date: 2016-09-30T07:59:32Z pdf:PDFVersion: 1.6 pdf:docinfo:title: Fault Reactivation Can Generate Hydraulic Short Circuits in Underground Coal Gasification?New Insights from Regional-Scale Thermo-Mechanical 3D Modeling xmp:CreatorTool: LaTeX with hyperref package access_permission:can_print_degraded: true subject: Underground coal gasification (UCG) has the potential to increase worldwide coal reserves by utilization of coal deposits not mineable by conventional methods. This involves combusting coal in situ to produce a synthesis gas, applicable for electricity generation and chemical feedstock production. Three-dimensional (3D) thermo-mechanical models already significantly contribute to UCG design by process optimization and mitigation of the environmental footprint. We developed the first 3D UCG model based on real structural geological data to investigate the impacts of using isothermal and non-isothermal simulations, two different pillar widths and four varying regional stress regimes on the spatial changes in temperature and permeability, ground surface subsidence and fault reactivation. Our simulation results demonstrate that non-isothermal processes have to be considered in these assessments due to thermally-induced stresses. Furthermore, we demonstrate that permeability increase is limited to the close reactor vicinity, although the presence of previously undetected faults can introduce formation of hydraulic short circuits between single UCG channels over large distances. This requires particular consideration of potentially present sub-seismic faults in the exploration and site selection stages, since the required pillar widths may be easily underestimated in presence of faults with different orientations with respect to the regional stress regime. dc:format: application/pdf; version=1.6 pdf:docinfo:creator_tool: LaTeX with hyperref package access_permission:fill_in_form: true pdf:encrypted: false dc:title: Fault Reactivation Can Generate Hydraulic Short Circuits in Underground Coal Gasification?New Insights from Regional-Scale Thermo-Mechanical 3D Modeling modified: 2016-09-30T07:59:32Z cp:subject: Underground coal gasification (UCG) has the potential to increase worldwide coal reserves by utilization of coal deposits not mineable by conventional methods. This involves combusting coal in situ to produce a synthesis gas, applicable for electricity generation and chemical feedstock production. Three-dimensional (3D) thermo-mechanical models already significantly contribute to UCG design by process optimization and mitigation of the environmental footprint. We developed the first 3D UCG model based on real structural geological data to investigate the impacts of using isothermal and non-isothermal simulations, two different pillar widths and four varying regional stress regimes on the spatial changes in temperature and permeability, ground surface subsidence and fault reactivation. Our simulation results demonstrate that non-isothermal processes have to be considered in these assessments due to thermally-induced stresses. Furthermore, we demonstrate that permeability increase is limited to the close reactor vicinity, although the presence of previously undetected faults can introduce formation of hydraulic short circuits between single UCG channels over large distances. This requires particular consideration of potentially present sub-seismic faults in the exploration and site selection stages, since the required pillar widths may be easily underestimated in presence of faults with different orientations with respect to the regional stress regime. pdf:docinfo:subject: Underground coal gasification (UCG) has the potential to increase worldwide coal reserves by utilization of coal deposits not mineable by conventional methods. This involves combusting coal in situ to produce a synthesis gas, applicable for electricity generation and chemical feedstock production. Three-dimensional (3D) thermo-mechanical models already significantly contribute to UCG design by process optimization and mitigation of the environmental footprint. We developed the first 3D UCG model based on real structural geological data to investigate the impacts of using isothermal and non-isothermal simulations, two different pillar widths and four varying regional stress regimes on the spatial changes in temperature and permeability, ground surface subsidence and fault reactivation. Our simulation results demonstrate that non-isothermal processes have to be considered in these assessments due to thermally-induced stresses. Furthermore, we demonstrate that permeability increase is limited to the close reactor vicinity, although the presence of previously undetected faults can introduce formation of hydraulic short circuits between single UCG channels over large distances. This requires particular consideration of potentially present sub-seismic faults in the exploration and site selection stages, since the required pillar widths may be easily underestimated in presence of faults with different orientations with respect to the regional stress regime. pdf:docinfo:creator: Christopher Otto, Thomas Kempka, Krzysztof Kapusta and Krzysztof Sta?czyk PTEX.Fullbanner: This is pdfTeX, Version 3.14159265-2.6-1.40.15 (TeX Live 2014/W32TeX) kpathsea version 6.2.0 meta:author: Christopher Otto, Thomas Kempka, Krzysztof Kapusta and Krzysztof Sta?czyk trapped: False meta:creation-date: 2016-09-29T02:19:37Z created: 2016-09-29T02:19:37Z access_permission:extract_for_accessibility: true Creation-Date: 2016-09-29T02:19:37Z Author: Christopher Otto, Thomas Kempka, Krzysztof Kapusta and Krzysztof Sta?czyk producer: pdfTeX-1.40.15 pdf:docinfo:producer: pdfTeX-1.40.15 pdf:unmappedUnicodeCharsPerPage: 0 dc:description: Underground coal gasification (UCG) has the potential to increase worldwide coal reserves by utilization of coal deposits not mineable by conventional methods. This involves combusting coal in situ to produce a synthesis gas, applicable for electricity generation and chemical feedstock production. Three-dimensional (3D) thermo-mechanical models already significantly contribute to UCG design by process optimization and mitigation of the environmental footprint. We developed the first 3D UCG model based on real structural geological data to investigate the impacts of using isothermal and non-isothermal simulations, two different pillar widths and four varying regional stress regimes on the spatial changes in temperature and permeability, ground surface subsidence and fault reactivation. Our simulation results demonstrate that non-isothermal processes have to be considered in these assessments due to thermally-induced stresses. Furthermore, we demonstrate that permeability increase is limited to the close reactor vicinity, although the presence of previously undetected faults can introduce formation of hydraulic short circuits between single UCG channels over large distances. This requires particular consideration of potentially present sub-seismic faults in the exploration and site selection stages, since the required pillar widths may be easily underestimated in presence of faults with different orientations with respect to the regional stress regime. Keywords: underground coal gasification; thermo-mechanical modeling; numerical simulation; environmental impacts; fault reactivation access_permission:modify_annotations: true dc:creator: Christopher Otto, Thomas Kempka, Krzysztof Kapusta and Krzysztof Sta?czyk description: Underground coal gasification (UCG) has the potential to increase worldwide coal reserves by utilization of coal deposits not mineable by conventional methods. This involves combusting coal in situ to produce a synthesis gas, applicable for electricity generation and chemical feedstock production. Three-dimensional (3D) thermo-mechanical models already significantly contribute to UCG design by process optimization and mitigation of the environmental footprint. We developed the first 3D UCG model based on real structural geological data to investigate the impacts of using isothermal and non-isothermal simulations, two different pillar widths and four varying regional stress regimes on the spatial changes in temperature and permeability, ground surface subsidence and fault reactivation. Our simulation results demonstrate that non-isothermal processes have to be considered in these assessments due to thermally-induced stresses. Furthermore, we demonstrate that permeability increase is limited to the close reactor vicinity, although the presence of previously undetected faults can introduce formation of hydraulic short circuits between single UCG channels over large distances. This requires particular consideration of potentially present sub-seismic faults in the exploration and site selection stages, since the required pillar widths may be easily underestimated in presence of faults with different orientations with respect to the regional stress regime. dcterms:created: 2016-09-29T02:19:37Z Last-Modified: 2016-09-30T07:59:32Z dcterms:modified: 2016-09-30T07:59:32Z title: Fault Reactivation Can Generate Hydraulic Short Circuits in Underground Coal Gasification?New Insights from Regional-Scale Thermo-Mechanical 3D Modeling xmpMM:DocumentID: uuid:c7ffb584-de86-4720-8990-4762f2ea21c6 Last-Save-Date: 2016-09-30T07:59:32Z pdf:docinfo:keywords: underground coal gasification; thermo-mechanical modeling; numerical simulation; environmental impacts; fault reactivation pdf:docinfo:modified: 2016-09-30T07:59:32Z meta:save-date: 2016-09-30T07:59:32Z pdf:docinfo:custom:PTEX.Fullbanner: This is pdfTeX, Version 3.14159265-2.6-1.40.15 (TeX Live 2014/W32TeX) kpathsea version 6.2.0 Content-Type: application/pdf X-Parsed-By: org.apache.tika.parser.DefaultParser creator: Christopher Otto, Thomas Kempka, Krzysztof Kapusta and Krzysztof Sta?czyk dc:subject: underground coal gasification; thermo-mechanical modeling; numerical simulation; environmental impacts; fault reactivation access_permission:assemble_document: true xmpTPg:NPages: 19 pdf:charsPerPage: 319 access_permission:extract_content: true access_permission:can_print: true pdf:docinfo:trapped: False meta:keyword: underground coal gasification; thermo-mechanical modeling; numerical simulation; environmental impacts; fault reactivation access_permission:can_modify: true pdf:docinfo:created: 2016-09-29T02:19:37Z