Characterisation of Surat Basin Walloon interburden and overlying Springbok Sandstone: a focus on methane adsorption isotherms, permeability and gas content
Syed Shabbar Raza A C , Julie Pearce A , Pradeep Shukla B , Phil Hayes A and Victor Rudolph BA UQ Centre for Natural Gas, The University of Queensland, Qld 4072, Australia.
B School of Chemical Engineering, The University of Queensland, Qld 4072, Australia.
C Corresponding author. Email: syed.raza@uq.net.au
The APPEA Journal 60(2) 748-752 https://doi.org/10.1071/AJ19078
Accepted: 19 February 2020 Published: 15 May 2020
Abstract
The Surat Basin in Queensland is one of the world’s premier producers of natural gas from coal seams. We investigate the potential for clay-rich Walloon Coal interburden and the overlying Springbok Sandstone to hold or produce gas. Seventeen core samples were analysed from two wells from intervals within the Walloon Upper Juandah Coal Measures interburden and the Springbok Sandstone. Samples were characterised using high-pressure methane adsorption isotherms, canister gas desorption tests, moisture contents, ash contents, carbon contents, scanning electron microscopy/energy dispersive X-ray spectrometry, X-ray quantitative clay analysis, permeability, helium pycnometry and mercury intrusion porosimetry. Methane adsorption was conducted at 30°C with up to 8 MPa pressure on dried crushed samples. The adsorption capacity of methane at 8 MPa varied from 3 cc/g (calcite-cemented) up to 25 cc/g (standard temperature and pressure equivalent) (coal). Clay-rich interburden samples adsorbed ~5–14 cc/g (dry). The measured isotherms and methane content from canister desorption tests show that appreciable volumes of gas are contained within some portions of interburden and in the overlying Springbok Sandstone. Gas within the interburden likely represents a large volumetric resource, albeit in low permeability rock that restricts direct productivity. The gas adsorption and gas content results for the Springbok Sandstone help to explain field observations of high gas content in some landholder water wells.
Keywords: ash contents, bulk density, canister desorption, coal, formation pressure, helium pycnometry, Langmuir isotherm, lithology, mercury intrusion porosimetry (MIP), moisture contents, mudstone, permeability, porosity, quantitative clay analysis XRD, scanning electron microscopy (SEM), skeleton density, stratigraphy, total carbon contents (TC), total organic carbon (TOC) contents, triaxial stress permeameter rig, Walloon Subgroup.
Dr Syed Shabbar Raza works in the University of Queensland (UQ) Centre for Natural Gas as Postdoctoral Research Fellow. He completed his PhD from the School of Chemical Engineering, also at UQ. Syed is the member of Engineers Australia (MIAust). Syed has over 15 years of research and development experience and is well versed in Australian standards. |
Dr Julia Pearce works as a Research Fellow at the UQ Centre for Natural Gas. Julie’s research mainly focuses on gas-water-rock core reactivity at reservoir conditions using experimental and geochemical modelling techniques. Her recent projects look at how CO2 is captured from sources, such as the burning of fossil fuels, and stored in geological formations that are generally contained by low permeability cap-rock, with a particular focus on safe containment of injected CO2 and the potential changes to rock porosity, permeability and water quality. Her recent and current projects also focus on a demonstration site in the Surat Basin (Precipice Sandstone) and include the impacts of impurity or acid gases present in industrial CO2 streams (in collaboration with D. Kirste, Simon Fraser University). Julie is also working on field sampling methods for gas and water in coal seam gas (CSG) and overlying aquifers. |
Dr Pradeep Shukla works as a Senior Research Fellow in the Queensland Alliance for Environmental Health Sciences, Faculty of Health and Behavioural Sciences at UQ. Dr Shukla completed his PhD from Curtin University. |
Dr Phil Hayes is an Associate Professor of Water Resources and Gas Development in the UQ Centre for Natural Gas. Phil’s research focuses on groundwater and its interaction with gas and the CSG industry and in groundwater modelling, uncertainty and communication. Prior to joining UQ, Phil worked as a consultant in the water, mining, oil and gas and nuclear sectors in Australia, the UK and South America. Dr Hayes completed his PhD from the University of Birmingham, UK. |
Following 12 years industrial experience in large-scale chemical plant design, operations and project management, Victor Rudolph joined the Department of Chemical Engineering at UQ in 1987. He became the Head of the department in 1996 for a 4-year term. In 1998, he assumed a 3-year term as Director of the UQ Technology and Information Management Centre. He is currently a Professor of Chemical Engineering at UQ and Director of the Baosteel-Australia Joint Research and Development Centre. |
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