Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling
Thermo-mechanical drilling combines the advantages of flame thermal treatment and rotary head drilling to achieve a high penetration rate in granitic rocks and a low wear rate of drill bits. This drilling strategy has been recognized as a potential technique to develop deep geothermal energy, but fu...
Saved in:
Main Authors: | , , , |
---|---|
Other Authors: | |
Format: | Article |
Language: | English |
Published: |
2022
|
Subjects: | |
Online Access: | https://hdl.handle.net/10356/155218 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Institution: | Nanyang Technological University |
Language: | English |
id |
sg-ntu-dr.10356-155218 |
---|---|
record_format |
dspace |
spelling |
sg-ntu-dr.10356-1552182022-02-22T02:22:10Z Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling Ji, Yinlin Wang, Lu Zheng, Yanlong Wu, Wei School of Civil and Environmental Engineering Engineering::Civil engineering Thermal Treatment Cerchar Abrasivity Index Thermo-mechanical drilling combines the advantages of flame thermal treatment and rotary head drilling to achieve a high penetration rate in granitic rocks and a low wear rate of drill bits. This drilling strategy has been recognized as a potential technique to develop deep geothermal energy, but further improvement is still needed to optimize the drilling efficiency, such as the reduction in drill bit wear in thermally treated rocks. We use the Cerchar abrasivity test to investigate the abrasivity characteristics of Bukit Timah granite after the thermal treatment at different high temperatures. The Cerchar abrasivity index (CAI) decreases from 3.5 at 25 °C to 3.0 at 400 °C, remains constant between 400 and 600 °C and subsequently increases to 4.1 at 800 °C. Based on the meso-scale and micro-scale observations using polarizing microscope, 3D scanner and scanning electron microscope, the reduction in CAI value at lower temperatures is due to the abrasive wear of stylus tip, while the mechanical interaction between the stylus cone and abrasive minerals causes the increase in CAI value at higher temperatures. The Cerchar abrasivity test results indicate that overheating rocks may result in the exposure of drill bits to more abrasive minerals and enhance drill bit wear. Nanyang Technological University Wei Wu gratefully acknowledges the support of Start-Up Grant from Nanyang Technological University, Singapore 2022-02-22T02:22:10Z 2022-02-22T02:22:10Z 2021 Journal Article Ji, Y., Wang, L., Zheng, Y. & Wu, W. (2021). Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling. Acta Geotechnica, 16(3), 885-893. https://dx.doi.org/10.1007/s11440-020-01056-x 1861-1125 https://hdl.handle.net/10356/155218 10.1007/s11440-020-01056-x 2-s2.0-85089699775 3 16 885 893 en Acta Geotechnica © 2020 Springer-Verlag GmbH Germany, part of Springer Nature. All rights reserved. |
institution |
Nanyang Technological University |
building |
NTU Library |
continent |
Asia |
country |
Singapore Singapore |
content_provider |
NTU Library |
collection |
DR-NTU |
language |
English |
topic |
Engineering::Civil engineering Thermal Treatment Cerchar Abrasivity Index |
spellingShingle |
Engineering::Civil engineering Thermal Treatment Cerchar Abrasivity Index Ji, Yinlin Wang, Lu Zheng, Yanlong Wu, Wei Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling |
description |
Thermo-mechanical drilling combines the advantages of flame thermal treatment and rotary head drilling to achieve a high penetration rate in granitic rocks and a low wear rate of drill bits. This drilling strategy has been recognized as a potential technique to develop deep geothermal energy, but further improvement is still needed to optimize the drilling efficiency, such as the reduction in drill bit wear in thermally treated rocks. We use the Cerchar abrasivity test to investigate the abrasivity characteristics of Bukit Timah granite after the thermal treatment at different high temperatures. The Cerchar abrasivity index (CAI) decreases from 3.5 at 25 °C to 3.0 at 400 °C, remains constant between 400 and 600 °C and subsequently increases to 4.1 at 800 °C. Based on the meso-scale and micro-scale observations using polarizing microscope, 3D scanner and scanning electron microscope, the reduction in CAI value at lower temperatures is due to the abrasive wear of stylus tip, while the mechanical interaction between the stylus cone and abrasive minerals causes the increase in CAI value at higher temperatures. The Cerchar abrasivity test results indicate that overheating rocks may result in the exposure of drill bits to more abrasive minerals and enhance drill bit wear. |
author2 |
School of Civil and Environmental Engineering |
author_facet |
School of Civil and Environmental Engineering Ji, Yinlin Wang, Lu Zheng, Yanlong Wu, Wei |
format |
Article |
author |
Ji, Yinlin Wang, Lu Zheng, Yanlong Wu, Wei |
author_sort |
Ji, Yinlin |
title |
Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling |
title_short |
Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling |
title_full |
Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling |
title_fullStr |
Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling |
title_full_unstemmed |
Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling |
title_sort |
temperature-dependent abrasivity of bukit timah granite and implications for drill bit wear in thermo-mechanical drilling |
publishDate |
2022 |
url |
https://hdl.handle.net/10356/155218 |
_version_ |
1725985694836326400 |