Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach
Geochemical processes change the microstructure of rocks and thereby affect their physical behaviour at the macro scale. A micro-computer tomography (micro-CT) scan of a typical reservoir sandstone is used to numerically examine the impact of three spatial alteration patterns on pore morphology, per...
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doaj-1a2110fbe0694a1599b8d93f633d6df92020-11-25T03:12:30ZengMDPI AGMaterials1996-19442020-07-01133100310010.3390/ma13143100Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation ApproachMaria Wetzel0Thomas Kempka1Michael Kühn2German Research Centre for Geosciences, Fluid Systems Modelling, Telegrafenberg, 14473 Potsdam, GermanyGerman Research Centre for Geosciences, Fluid Systems Modelling, Telegrafenberg, 14473 Potsdam, GermanyGerman Research Centre for Geosciences, Fluid Systems Modelling, Telegrafenberg, 14473 Potsdam, GermanyGeochemical processes change the microstructure of rocks and thereby affect their physical behaviour at the macro scale. A micro-computer tomography (micro-CT) scan of a typical reservoir sandstone is used to numerically examine the impact of three spatial alteration patterns on pore morphology, permeability and elastic moduli by correlating precipitation with the local flow velocity magnitude. The results demonstrate that the location of mineral growth strongly affects the permeability decrease with variations by up to four orders in magnitude. Precipitation in regions of high flow velocities is characterised by a predominant clogging of pore throats and a drastic permeability reduction, which can be roughly described by the power law relation with an exponent of 20. A continuous alteration of the pore structure by uniform mineral growth reduces the permeability comparable to the power law with an exponent of four or the Kozeny–Carman relation. Preferential precipitation in regions of low flow velocities predominantly affects smaller throats and pores with a minor impact on the flow regime, where the permeability decrease is considerably below that calculated by the power law with an exponent of two. Despite their complete distinctive impact on hydraulics, the spatial precipitation patterns only slightly affect the increase in elastic rock properties with differences by up to 6.3% between the investigated scenarios. Hence, an adequate characterisation of the spatial precipitation pattern is crucial to quantify changes in hydraulic rock properties, whereas the present study shows that its impact on elastic rock parameters is limited. The calculated relations between porosity and permeability, as well as elastic moduli can be applied for upscaling micro-scale findings to reservoir-scale models to improve their predictive capabilities, what is of paramount importance for a sustainable utilisation of the geological subsurface.https://www.mdpi.com/1996-1944/13/14/3100Bentheim sandstonedigital rock physicsmicro-CTelastic propertiespermeabilityprecipitation |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Maria Wetzel Thomas Kempka Michael Kühn |
spellingShingle |
Maria Wetzel Thomas Kempka Michael Kühn Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach Materials Bentheim sandstone digital rock physics micro-CT elastic properties permeability precipitation |
author_facet |
Maria Wetzel Thomas Kempka Michael Kühn |
author_sort |
Maria Wetzel |
title |
Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach |
title_short |
Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach |
title_full |
Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach |
title_fullStr |
Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach |
title_full_unstemmed |
Hydraulic and Mechanical Impacts of Pore Space Alterations within a Sandstone Quantified by a Flow Velocity-Dependent Precipitation Approach |
title_sort |
hydraulic and mechanical impacts of pore space alterations within a sandstone quantified by a flow velocity-dependent precipitation approach |
publisher |
MDPI AG |
series |
Materials |
issn |
1996-1944 |
publishDate |
2020-07-01 |
description |
Geochemical processes change the microstructure of rocks and thereby affect their physical behaviour at the macro scale. A micro-computer tomography (micro-CT) scan of a typical reservoir sandstone is used to numerically examine the impact of three spatial alteration patterns on pore morphology, permeability and elastic moduli by correlating precipitation with the local flow velocity magnitude. The results demonstrate that the location of mineral growth strongly affects the permeability decrease with variations by up to four orders in magnitude. Precipitation in regions of high flow velocities is characterised by a predominant clogging of pore throats and a drastic permeability reduction, which can be roughly described by the power law relation with an exponent of 20. A continuous alteration of the pore structure by uniform mineral growth reduces the permeability comparable to the power law with an exponent of four or the Kozeny–Carman relation. Preferential precipitation in regions of low flow velocities predominantly affects smaller throats and pores with a minor impact on the flow regime, where the permeability decrease is considerably below that calculated by the power law with an exponent of two. Despite their complete distinctive impact on hydraulics, the spatial precipitation patterns only slightly affect the increase in elastic rock properties with differences by up to 6.3% between the investigated scenarios. Hence, an adequate characterisation of the spatial precipitation pattern is crucial to quantify changes in hydraulic rock properties, whereas the present study shows that its impact on elastic rock parameters is limited. The calculated relations between porosity and permeability, as well as elastic moduli can be applied for upscaling micro-scale findings to reservoir-scale models to improve their predictive capabilities, what is of paramount importance for a sustainable utilisation of the geological subsurface. |
topic |
Bentheim sandstone digital rock physics micro-CT elastic properties permeability precipitation |
url |
https://www.mdpi.com/1996-1944/13/14/3100 |
work_keys_str_mv |
AT mariawetzel hydraulicandmechanicalimpactsofporespacealterationswithinasandstonequantifiedbyaflowvelocitydependentprecipitationapproach AT thomaskempka hydraulicandmechanicalimpactsofporespacealterationswithinasandstonequantifiedbyaflowvelocitydependentprecipitationapproach AT michaelkuhn hydraulicandmechanicalimpactsofporespacealterationswithinasandstonequantifiedbyaflowvelocitydependentprecipitationapproach |
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