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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ftdoajarticles:oai:doaj.org/article:95de350a6d4447759e923a31eb6f30c7 2023-05-15T16:12:07+02:00 Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data Peter Leary Peter Malin Tero Saarno Ilmo Kukkonen 2017-11-01T00:00:00Z https://doi.org/10.3390/en10121979 https://doaj.org/article/95de350a6d4447759e923a31eb6f30c7 EN eng MDPI AG https://www.mdpi.com/1996-1073/10/12/1979 https://doaj.org/toc/1996-1073 1996-1073 doi:10.3390/en10121979 https://doaj.org/article/95de350a6d4447759e923a31eb6f30c7 Energies, Vol 10, Iss 12, p 1979 (2017) enhanced geothermal systems (EGS) crustal permeability finite element flow modelling crustal wellbore temperatures wellbore injection well logs well core Technology T article 2017 ftdoajarticles https://doi.org/10.3390/en10121979 2022-12-30T20:00:37Z 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. Article in Journal/Newspaper Fennoscandia Directory of Open Access Journals: DOAJ Articles Energies 10 12 1979 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
enhanced geothermal systems (EGS) crustal permeability finite element flow modelling crustal wellbore temperatures wellbore injection well logs well core Technology T |
spellingShingle |
enhanced geothermal systems (EGS) crustal permeability finite element flow modelling crustal wellbore temperatures wellbore injection well logs well core Technology T Peter Leary Peter Malin Tero Saarno Ilmo Kukkonen Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data |
topic_facet |
enhanced geothermal systems (EGS) crustal permeability finite element flow modelling crustal wellbore temperatures wellbore injection well logs well core Technology T |
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. |
format |
Article in Journal/Newspaper |
author |
Peter Leary Peter Malin Tero Saarno Ilmo Kukkonen |
author_facet |
Peter Leary Peter Malin Tero Saarno Ilmo Kukkonen |
author_sort |
Peter Leary |
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 |
publisher |
MDPI AG |
publishDate |
2017 |
url |
https://doi.org/10.3390/en10121979 https://doaj.org/article/95de350a6d4447759e923a31eb6f30c7 |
genre |
Fennoscandia |
genre_facet |
Fennoscandia |
op_source |
Energies, Vol 10, Iss 12, p 1979 (2017) |
op_relation |
https://www.mdpi.com/1996-1073/10/12/1979 https://doaj.org/toc/1996-1073 1996-1073 doi:10.3390/en10121979 https://doaj.org/article/95de350a6d4447759e923a31eb6f30c7 |
op_doi |
https://doi.org/10.3390/en10121979 |
container_title |
Energies |
container_volume |
10 |
container_issue |
12 |
container_start_page |
1979 |
_version_ |
1765997358009548800 |