Publication details

Geological Perspectives from the First Deep Exploratory Slimhole in Singapore

Publication data

Type:
Chapter in multi-author book
Authors:
Jonathan Poh, Hendrik Tjiawi, Wei Wu, Alessandro Romagnoli, Tobias Massier, Cliff Khiok Eng Chua, Jian Wei Mark Lim, Lizhong Yang, Dazhao Lu, Anurag Chidire, Balaganesha Balasubramaniam Veerasamy and Jerry Chan Sin Loong
Published in:
Lecture Notes in Civil Engineering, vol. 471
(Electronic ISBN: 978-981-97-1257-1, Print ISBN: 978-981-97-1256-4) (Electronic ISSN: 2366-2565, Print ISSN: 2366-2557)
Issue:
Publisher:
Springer, Heidelberg (Baden-Württemberg, Germany)
Publication date:
July 2024
Pages:
1231–1233
Abstract:
A deep exploratory slimhole reaching a depth of approximately 1.1 km was successfully completed in the northern part of Singapore. The rock cores extracted from the exploration slimhole provide a unique opportunity to understand rock conditions past few hundred metres deep and generate datasets such as overall rock conditions and concentrations of various elements. Good-quality rocks are seen in most of the rock samples with coarse-to-medium-grained minerals. The rock cores are found to be lightly fractured and jointed. Hydrothermal alteration, as observed in rock cores at various depths (e.g. 500 m and 670 m), destroyed the original granitic texture. The rock cores have averaged heat production values of around 5 µW·m−3 throughout the borehole. Two zones of very poor rock quality are observed at around 565 m and 1.1 km deep. The rocks at both weak zones are found to be extremely weak, highly weathered and brecciated, contain specular hematite filling, and have low heat production of around 3.5 µW·m−3. The second and deeper weak zone consists of a continuous zone of highly weathered and altered fine sand to pebble-sized rock fragments exhibiting a potential cataclastic texture. Here, heat production values are observed to be around 1 µW·m−3. Highly altered and weathered rocks within these weak/porous zones indicate fluid-rock interactions. However, their vertical and lateral extents are not well constrained and should be investigated further. If similar zones are found at greater depths, they could be utilised as natural conduits for fluid circulation to extract heat from hot rocks, thereby reducing the potential need for rock fracturing.
Keywords:
Geology, Rock core, Geothermal, Singapore granite
DOI:

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@incollection{Poh_GeologicalPerspectivesFirst_2024,
  author    = {Poh, Jonathan and Tjiawi, Hendrik and Wu, Wei and Romagnoli, Alessandro and Massier, Tobias and Chua, Cliff Khiok Eng and Lim, Jian Wei Mark and Yang, Lizhong and Lu, Dazhao and Chidire, Anurag and Veerasamy, Balaganesha Balasubramaniam and Loong, Jerry Chan Sin},
  title     = {Geological Perspectives from the First Deep Exploratory Slimhole in {Singapore}},
  year      = {2024},
  month     = jul,
  booktitle = {Lecture Notes in Civil Engineering},
  isbn      = {978-981-97-1257-1},
  issn      = {2366-2565},
  publisher = {Springer},
  address   = {Heidelberg, Germany},
  chapter   = {169},
  volume    = {471},
  pages     = {1231--1233},
  doi       = {10.1007/978-981-97-1257-1\_169},
  keywords  = {Geology, Rock core, Geothermal, Singapore granite},
}
@incollection{Poh_GeologicalPerspectivesFirst_2024,
  author     = {Poh, Jonathan and Tjiawi, Hendrik and Wu, Wei and Romagnoli, Alessandro and Massier, Tobias and Chua, Cliff Khiok Eng and Lim, Jian Wei Mark and Yang, Lizhong and Lu, Dazhao and Chidire, Anurag and Veerasamy, Balaganesha Balasubramaniam and Loong, Jerry Chan Sin},
  title      = {Geological Perspectives from the First Deep Exploratory Slimhole in {Singapore}},
  date       = {2024-07},
  booktitle  = {Lecture Notes in Civil Engineering},
  issuetitle = {Proceedings of the 18th Conference of the Associated Research Centers for the Urban Underground Space (ACUUS 2023)},
  isbn       = {978-981-97-1257-1},
  issn       = {2366-2565},
  publisher  = {Springer},
  location   = {Heidelberg, Germany},
  chapter    = {169},
  volume     = {471},
  pages      = {1231--1233},
  doi        = {10.1007/978-981-97-1257-1\_169},
  keywords   = {Geology, Rock core, Geothermal, Singapore granite},
}

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