Gas permeability measurement of shales using the quasi steady-state technique
M. Nadia Testamanti A B , Reza Rezaee A and Christopher Wong AA Department of Petroleum Engineering, Curtin University, Perth, WA, Australia.
B Corresponding author. Email: m.testamanti@postgrad.curtin.edu.au
The APPEA Journal 57(2) 656-659 https://doi.org/10.1071/AJ16181
Accepted: 17 March 2017 Published: 29 May 2017
Abstract
The decline in reserves from conventional reservoirs, paired with the technological advances made in the drilling, stimulation and production areas over the last two decades have placed unconventional reservoirs in the limelight. Shale plays, in particular, have become increasingly attractive prospects and production from these reservoirs has increased significantly during this period.
Most of the petrophysical characterisation techniques routinely used in the laboratory were originally developed for rocks with relatively high porosity and permeability, making some of them unsuitable for tight rocks. Gas permeability measurements in shales can be particularly challenging due to their small pore and pore throat sizes, and even the validity of Darcy’s law under these conditions needs to be evaluated. The steady-state technique is generally unsuitable for measuring gas permeability in shales due to technical limitations of the instruments required, so the quasi steady-state method is proposed as an alternative.
This paper presents the results of gas permeability measurements conducted on two shale core plugs using the quasi steady-state technique. Although the effect of variations in ambient conditions is not usually significant for tests performed on cores from conventional reservoirs, our results indicate that it should not be overlooked when experiments are conducted on shale samples. Furthermore, the length of the core plugs should be minimised to reduce the time required to measure gas permeability.
Keywords: core analysis, gas permeability, quasi-steady state technique, shale reservoirs.
M. Nadia Testamanti is a PhD candidate in the Department of Petroleum Engineering at Curtin University. Her research focuses on the characterisation of the pore network and gas flow properties in shale reservoirs. Concurrent with her PhD studies, she has worked as Teaching Assistant for the Petrophysics and Formation Evaluation units at Curtin University. She has over 5 years’ experience in the oil and gas industry and before beginning her doctoral studies, she worked as a reservoir engineer for Pan American Energy (2011–14) in Argentina. She holds a Bachelor’s degree and a Diploma in Petroleum Engineering from ITBA University, Argentina. |
Professor Reza Rezaee of Curtin’s Department of Petroleum Engineering has a PhD degree in Reservoir Characterisation. He has over 26 years’ experience in academia, being responsible for both teaching and research. During his career, he has been engaged in several research projects supported by major oil and gas companies and these commissions, together with his supervisory work at various universities, have involved a wide range of achievements. He has received a total of more than $2.2M of funds through his collaborative research projects. He has supervised over 70 MSc and PhD students during his university career to date. He has published more than 130 peer-reviewed journal and conference papers, and is the author of four books on petroleum geology, logging and log interpretation and gas shale reservoirs. His research has been mostly on integrated solutions for reservoir characterisation, formation evaluation and petrophysics. Currently, he is focused on unconventional gas including gas shale and tight gas sand studies. As a founder of the Unconventional Gas Research Group of Australia, he has established a unique and highly sophisticated research laboratory at the Department of Petroleum Engineering, Curtin University. This laboratory was established to conduct research on petrophysical evaluation of tight gas sands and shale gas formations. He is the winner of an Australian Gas Innovation Award for his innovation on tight gas sand treatment for gas production enhancement. |
Christopher Wong holds a Bachelor of Petroleum Engineering degree from Curtin University. He graduated in 2016 with First-Class Honours and his thesis focused on the study of the gas flow properties of shale. He currently works as a QA/QC/Project Engineer for Shin Yang Sdn Bhd, in Malaysia, and is a member of the Society of Petroleum Engineers. |
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