Derbin, YG, Walker, J and Wanatowski, D orcid.org/0000-0002-5809-0374 (2018) Modelling surface subsidence during underground coal gasification. In: Deep Rock Mechanics: From Research to Engineering: Proceedings of the International Conference on Geo-Mechanics, Geo-Energy and Geo-Resources (IC3G 2018). International Conference on Geomechanics, Geo-energy and Geo-resources, 21-24 Sep 2018, Chengdu, P.R. China. , pp. 3-9. ISBN 978-1-138-48761-1
Abstract
Underground Coal Gasification (UCG) is an alternative method of extracting energy from coal whereby the coal is burnt within an in situ UCG reactor. The method has been established for almost a century, but it has not been widely used despite its advantages, which include the circumvention of underground human presence and the possibility to work with low quality coal that is deep underground. One of the main difficulties associated with the implementation of UCG on an industrial scale is the prediction of surface subsidence, which is required to assess potential damage to surface infrastructure, UCG equipment, and boreholes. This work considers the numerical modelling of surface subsidence during UCG. For this, the finite difference numerical modelling software FLAC3D by Itasca is utilized. Historically, this tool has been used for modelling surface settlement caused by traditional coal mining activities. The mechanism of surface subsidence during conventional coal mining and UCG are almost identical; however, the UCG reactor has some distinguishing features, for example, thermal strains and the resulting altered mechanical properties of the soil-rock. In this work, firstly, a thermal analysis is run to impose the thermal fields. Secondly, the engineering properties relationship with temperature is implemented in the model. Finally, model results are compared with field observations and discussed. The conclusion is drawn that updating the mechanical properties, i.e. elastic stiffness, friction angle and cohesion, in correlation with the elevated temperatures improves the surface subsidence predictions.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This item is protected by copyright. This is an Accepted Manuscript of an article published by Taylor & Francis in Deep Rock Mechanics: From Research to Engineering: Proceedings of the International Conference on Geo-Mechanics, Geo-Energy and Geo-Resources (IC3G 2018) on 13 Dec 2018, available online: https://www.taylorfrancis.com/books/e/9781351042666/chapters/10.1201/9781351042666-1 |
Keywords: | Underground Coal Gasification; Surface Subsidence; Numerical Modelling; Thermal Analysis; FLAC3D |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > SWJTU Joint School (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 19 Aug 2020 14:42 |
Last Modified: | 19 Aug 2020 18:58 |
Status: | Published |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:164343 |