Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data
We use Matlab 3D finite element fluid flow/transport modelling to simulate localized wellbore temperature events of order 0.05–0.1 °C logged in Fennoscandia basement rock at ~1.5 km depths. The temperature events are approximated as steady-state heat transport due to fluid draining from the crust in...
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/230876 2024-01-07T09:43:10+01:00 Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data Leary, Peter Malin, Peter Saarno, Tero Kukkonen, Ilmo Department of Physics 2018-01-09T14:05:01Z application/pdf http://hdl.handle.net/10138/230876 eng eng 10.3390/en10121979 Subtle energies & energy medicine Leary , P , Malin , P , Saarno , T & Kukkonen , I 2017 , ' Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data ' , Subtle energies & energy medicine , vol. 10 , no. 12 . https://doi.org/10.3390/en10121979 Bibtex: urn:86e53b6b302917203e220dfc6fb8d475 85044506531 e1a7f55b-1ceb-40ad-b54b-1809a61bf7fb http://hdl.handle.net/10138/230876 000423156900050 cc_by openAccess info:eu-repo/semantics/openAccess 114 Physical sciences Article publishedVersion 2018 ftunivhelsihelda 2023-12-14T00:09:52Z We use Matlab 3D finite element fluid flow/transport modelling to simulate localized wellbore temperature events of order 0.05–0.1 °C logged in Fennoscandia basement rock at ~1.5 km depths. The temperature events are approximated as steady-state heat transport due to fluid draining from the crust into the wellbore via naturally occurring fracture-connectivity structures. Flow simulation is based on the empirics of spatially-correlated fracture-connectivity fluid flow widely attested by well-log, well-core, and well-production data. Matching model wellbore-centric radial temperature profiles to a 2D analytic expression for steady-state radial heat transport with Peclet number Pe ≡ r0φv0/D (r0 = wellbore radius, v0 = Darcy velocity at r0, φ = ambient porosity, D = rock-water thermal diffusivity), gives Pe ~ 10–15 for fracture-connectivity flow intersecting the well, and Pe ~ 0 for ambient crust. Darcy flow for model Pe ~ 10 at radius ~10 m from the wellbore gives permeability estimate κ ~ 0.02 Darcy for flow driven by differential fluid pressure between least principal crustal stress pore pressure and hydrostatic wellbore pressure. Model temperature event flow permeability κm ~ 0.02 Darcy is related to well-core ambient permeability κ ~ 1 µDarcy by empirical poroperm relation κm ~ κ exp(αmφ) for φ ~ 0.01 and αm ~ 1000. Our modelling of OTN1 wellbore temperature events helps assess the prospect of reactivating fossilized fracture-connectivity flow for EGS permeability stimulation of basement rock. Peer reviewed Article in Journal/Newspaper Fennoscandia HELDA – University of Helsinki Open Repository Energies 10 12 1979 |
institution |
Open Polar |
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HELDA – University of Helsinki Open Repository |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
114 Physical sciences |
spellingShingle |
114 Physical sciences Leary, Peter Malin, Peter Saarno, Tero Kukkonen, Ilmo Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data |
topic_facet |
114 Physical sciences |
description |
We use Matlab 3D finite element fluid flow/transport modelling to simulate localized wellbore temperature events of order 0.05–0.1 °C logged in Fennoscandia basement rock at ~1.5 km depths. The temperature events are approximated as steady-state heat transport due to fluid draining from the crust into the wellbore via naturally occurring fracture-connectivity structures. Flow simulation is based on the empirics of spatially-correlated fracture-connectivity fluid flow widely attested by well-log, well-core, and well-production data. Matching model wellbore-centric radial temperature profiles to a 2D analytic expression for steady-state radial heat transport with Peclet number Pe ≡ r0φv0/D (r0 = wellbore radius, v0 = Darcy velocity at r0, φ = ambient porosity, D = rock-water thermal diffusivity), gives Pe ~ 10–15 for fracture-connectivity flow intersecting the well, and Pe ~ 0 for ambient crust. Darcy flow for model Pe ~ 10 at radius ~10 m from the wellbore gives permeability estimate κ ~ 0.02 Darcy for flow driven by differential fluid pressure between least principal crustal stress pore pressure and hydrostatic wellbore pressure. Model temperature event flow permeability κm ~ 0.02 Darcy is related to well-core ambient permeability κ ~ 1 µDarcy by empirical poroperm relation κm ~ κ exp(αmφ) for φ ~ 0.01 and αm ~ 1000. Our modelling of OTN1 wellbore temperature events helps assess the prospect of reactivating fossilized fracture-connectivity flow for EGS permeability stimulation of basement rock. Peer reviewed |
author2 |
Department of Physics |
format |
Article in Journal/Newspaper |
author |
Leary, Peter Malin, Peter Saarno, Tero Kukkonen, Ilmo |
author_facet |
Leary, Peter Malin, Peter Saarno, Tero Kukkonen, Ilmo |
author_sort |
Leary, Peter |
title |
Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data |
title_short |
Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data |
title_full |
Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data |
title_fullStr |
Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data |
title_full_unstemmed |
Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data |
title_sort |
prospects for assessing enhanced geothermal system (egs) basement rock flow stimulation by wellbore temperature data |
publishDate |
2018 |
url |
http://hdl.handle.net/10138/230876 |
genre |
Fennoscandia |
genre_facet |
Fennoscandia |
op_relation |
10.3390/en10121979 Subtle energies & energy medicine Leary , P , Malin , P , Saarno , T & Kukkonen , I 2017 , ' Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data ' , Subtle energies & energy medicine , vol. 10 , no. 12 . https://doi.org/10.3390/en10121979 Bibtex: urn:86e53b6b302917203e220dfc6fb8d475 85044506531 e1a7f55b-1ceb-40ad-b54b-1809a61bf7fb http://hdl.handle.net/10138/230876 000423156900050 |
op_rights |
cc_by openAccess info:eu-repo/semantics/openAccess |
container_title |
Energies |
container_volume |
10 |
container_issue |
12 |
container_start_page |
1979 |
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1787424422073729024 |