Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam Treatment

Purposes In the process of in-situ steam-assisted oil shale extraction, the shear strength of oil shale plays a crucial role in the stability of injection and production wells as well as the mining gallery. Additionally, the shear strength of rock formation is influenced by temperature. The variatio...

Full description

Bibliographic Details
Main Authors: Jingzhe CAO, Dong YANG, Zhiqin KANG, Lihong FENG
Format: Article
Language:English
Published: Editorial Office of Journal of Taiyuan University of Technology 2024-03-01
Series:Taiyuan Ligong Daxue xuebao
Subjects:
Online Access:https://tyutjournal.tyut.edu.cn/englishpaper/show-2266.html
_version_ 1797208288061816832
author Jingzhe CAO
Dong YANG
Zhiqin KANG
Lihong FENG
author_facet Jingzhe CAO
Dong YANG
Zhiqin KANG
Lihong FENG
author_sort Jingzhe CAO
collection DOAJ
description Purposes In the process of in-situ steam-assisted oil shale extraction, the shear strength of oil shale plays a crucial role in the stability of injection and production wells as well as the mining gallery. Additionally, the shear strength of rock formation is influenced by temperature. The variations in the shear characteristics of oil shale under different temperatures and shear angles are investigated. Methods A steam generation apparatus was employed to heat the oil shale. In the experimental setup, steam temperatures were set at 100, 200, 300, 400, and 500 ℃, separately. Subsequently, the steam-treated oil shale was subjected to variable-angle shear experiments at shear angles of 45°, 55°, and 65°. According to the experiment results, the variable-angle shear parameters and peak shear strain of the oil shale were calculated. Furthermore, an analysis of the shear failure characteristics of the oil shale following exposure to different steam conditions was conducted. Findings The research findings can be summarized as follows: 1) At steam temperatures below 300 ℃, oil shale exhibits pronounced brittle failure characteristics, while at temperatures of 400 ℃ and 500 ℃, ductile failure characteristics becomes more evident; 2) The cohesion of oil shale first increases and then decreases with the increase of steam temperature. Similarly, the internal friction angle decreases initially with rising steam temperature, followed by an increase. The shear strength decreases as the shear angle increases; 3) The peak shear strain of the oil shale increases with steam temperature rising, and high shear angle has a significant impact on the peak shear strain of the rock; 4) The shear failure mode of the oil shale transitions from penetrating failure to combined failure with an increase in steam temperature, along with an increase in secondary cracks.
first_indexed 2024-04-24T09:36:25Z
format Article
id doaj.art-6770dc9f8639429fafe16b9121cd0b5d
institution Directory Open Access Journal
issn 1007-9432
language English
last_indexed 2024-04-24T09:36:25Z
publishDate 2024-03-01
publisher Editorial Office of Journal of Taiyuan University of Technology
record_format Article
series Taiyuan Ligong Daxue xuebao
spelling doaj.art-6770dc9f8639429fafe16b9121cd0b5d2024-04-15T09:17:32ZengEditorial Office of Journal of Taiyuan University of TechnologyTaiyuan Ligong Daxue xuebao1007-94322024-03-0155225225910.16355/j.tyut.1007-9432.202306371007-9432(2024)02-0252-08Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam TreatmentJingzhe CAO0Dong YANG1Zhiqin KANG2Lihong FENG3College of Mining Engineering; Taiyuan University of Technology, Taiyuan 030024, ChinaKey Laboratory of In-situ Property Improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, ChinaKey Laboratory of In-situ Property Improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, ChinaCollege of Mining Engineering; Taiyuan University of Technology, Taiyuan 030024, ChinaPurposes In the process of in-situ steam-assisted oil shale extraction, the shear strength of oil shale plays a crucial role in the stability of injection and production wells as well as the mining gallery. Additionally, the shear strength of rock formation is influenced by temperature. The variations in the shear characteristics of oil shale under different temperatures and shear angles are investigated. Methods A steam generation apparatus was employed to heat the oil shale. In the experimental setup, steam temperatures were set at 100, 200, 300, 400, and 500 ℃, separately. Subsequently, the steam-treated oil shale was subjected to variable-angle shear experiments at shear angles of 45°, 55°, and 65°. According to the experiment results, the variable-angle shear parameters and peak shear strain of the oil shale were calculated. Furthermore, an analysis of the shear failure characteristics of the oil shale following exposure to different steam conditions was conducted. Findings The research findings can be summarized as follows: 1) At steam temperatures below 300 ℃, oil shale exhibits pronounced brittle failure characteristics, while at temperatures of 400 ℃ and 500 ℃, ductile failure characteristics becomes more evident; 2) The cohesion of oil shale first increases and then decreases with the increase of steam temperature. Similarly, the internal friction angle decreases initially with rising steam temperature, followed by an increase. The shear strength decreases as the shear angle increases; 3) The peak shear strain of the oil shale increases with steam temperature rising, and high shear angle has a significant impact on the peak shear strain of the rock; 4) The shear failure mode of the oil shale transitions from penetrating failure to combined failure with an increase in steam temperature, along with an increase in secondary cracks.https://tyutjournal.tyut.edu.cn/englishpaper/show-2266.htmlrock mechanicsoil shalesteamvariable angle shearshear parameterfailure characteristics
spellingShingle Jingzhe CAO
Dong YANG
Zhiqin KANG
Lihong FENG
Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam Treatment
Taiyuan Ligong Daxue xuebao
rock mechanics
oil shale
steam
variable angle shear
shear parameter
failure characteristics
title Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam Treatment
title_full Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam Treatment
title_fullStr Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam Treatment
title_full_unstemmed Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam Treatment
title_short Study on Shear Failure Characteristics of Oil Shale under High-temperature Steam Treatment
title_sort study on shear failure characteristics of oil shale under high temperature steam treatment
topic rock mechanics
oil shale
steam
variable angle shear
shear parameter
failure characteristics
url https://tyutjournal.tyut.edu.cn/englishpaper/show-2266.html
work_keys_str_mv AT jingzhecao studyonshearfailurecharacteristicsofoilshaleunderhightemperaturesteamtreatment
AT dongyang studyonshearfailurecharacteristicsofoilshaleunderhightemperaturesteamtreatment
AT zhiqinkang studyonshearfailurecharacteristicsofoilshaleunderhightemperaturesteamtreatment
AT lihongfeng studyonshearfailurecharacteristicsofoilshaleunderhightemperaturesteamtreatment