Determination of T2 cut-off for shale reservoirs: a case study from the Carynginia formation, Perth Basin, Western Australia
M. Nadia Testamanti A B , Reza Rezaee A , Yujie Yuan A and Dawei Pan 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) 664-668 https://doi.org/10.1071/AJ16184
Accepted: 17 March 2017 Published: 29 May 2017
Abstract
Over recent decades, the low-field Nuclear Magnetic Resonance (NMR) method has been consistently used in the petroleum industry for the petrophysical characterisation of conventional reservoirs. Through this non-invasive technique, the porosity, pore size distribution and fluid properties can be determined from the signal emitted by fluids present in the porous media. Transverse relaxation (T2) data, in particular, are one of the most valuable sources of information in an NMR measurement, as the resulting signal decay can be inverted to obtain the T2 distribution of the rock, which can in turn be correlated with porosity and pore size distribution.
The complex pore network of shales, which can have a large portion of pore sizes in the nanopore and mesopore range, restricts the techniques that can be used to investigate their pore structure and porosity. The ability of the NMR technique to detect signals from a wide range of pores has therefore prompted the quest for more standardised interpretation methods suitable for shales.
Using low-field NMR, T2 experiments were performed on shale samples from the Carynginia formation, Perth Basin, at different saturation levels. The shale samples were initially saturated with brine and the T2 spectrum for each sample was obtained. Then, they were placed in a vacuum oven and their weight monitored until a constant value was reached. T2 curves were subsequently obtained for each of the oven-dried samples and a cut-off value for clay-bound water was calculated.
Keywords: clay bound water, nuclear magnetic resonance, transverse relaxation.
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 a 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 also the winner of an Australian Gas Innovation Award for his innovation on tight gas sand treatment for gas production enhancement. |
Yujie Yuan is a PhD student in Department of Petroleum Engineering at Curtin University. Her research focuses on the petrophysical characterisation of tight rocks. She holds a Bachelor of Petroleum Engineering degree from the China University of Petroleum (UPC, East China). |
Dawei Pan holds a Bachelor of Petroleum Engineering degree from Curtin University, obtained in 2015 with First-Class Honours. His final year project focused on the petrophysical evaluation of shale reservoirs with NMR. He currently works as a petroleum engineer in the digital rock physics area for Reservoir Rock Technologies in Perth. Dawei is also a member of the Society of Petroleum Engineers. |
References
API (1998). ‘Recommended practice for core-analysis procedure.’ (American Petroleum Institute: Washington, DC.)Chalmers, G. R., Bustin, R. M., and Power, I. M. (2012). Characterization of gas shale pore systems by porosimetry, pycnometry, surface area, and field emission scanning electron microscopy/transmission electron microscopy image analyses: Examples from the Barnett, Woodford, Haynesville, Marcellus, and Doig units. AAPG Bulletin 96, 1099–1119.
| Characterization of gas shale pore systems by porosimetry, pycnometry, surface area, and field emission scanning electron microscopy/transmission electron microscopy image analyses: Examples from the Barnett, Woodford, Haynesville, Marcellus, and Doig units.Crossref | GoogleScholarGoogle Scholar |
Clarkson, C. R., Jensen, J. L., and Blasingame, T. (2011). ‘Reservoir engineering for unconventional reservoirs: what do we have to consider?’ Paper presented at the SPE North American Unconventional Gas Conference and Exhibition, The Woodlands, Texas, USA. (Society of Petroleum Engineers.)
Drits, V. A., and McCarty, D. K. (2007). The nature of structure-bonded H2O in illite and leucophyllite from dehydration and dehydroxylation experiments. Clays and Clay Minerals 55, 45–58.
| The nature of structure-bonded H2O in illite and leucophyllite from dehydration and dehydroxylation experiments.Crossref | GoogleScholarGoogle Scholar |
Fleury, M., Kohler, E., Norrant, F., Gautier, S., M’Hamdi, J., and Barré, L. (2013). Characterization and Quantification of Water in Smectites with Low-Field NMR. The Journal of Physical Chemistry C 117, 4551–4560.
| Characterization and Quantification of Water in Smectites with Low-Field NMR.Crossref | GoogleScholarGoogle Scholar |
Hall, P. L., Astill, D. M., and McConnell, J. D. C. (1986). Thermodynamic and structural aspects of the dehydration of smectites in sedimentary rocks. Clay Minerals 21, 633–648.
| Thermodynamic and structural aspects of the dehydration of smectites in sedimentary rocks.Crossref | GoogleScholarGoogle Scholar |
Hueckel, T. (2002). Reactive plasticity for clays during dehydration and rehydration. Part 1: concepts and options. International Journal of Plasticity 18, 281–312.
| Reactive plasticity for clays during dehydration and rehydration. Part 1: concepts and options.Crossref | GoogleScholarGoogle Scholar |
Josh, M., Esteban, L., Delle Piane, C., Sarout, J., Dewhurst, D. N., and Clennell, M. B. (2012). Laboratory characterisation of shale properties. Journal of Petroleum Science Engineering 88–89, 107–124.
| Laboratory characterisation of shale properties.Crossref | GoogleScholarGoogle Scholar |
Loucks, R. G., Reed, R. M., Ruppel, S. C., and Hammes, U. (2012). Spectrum of pore types and networks in mudrocks and a descriptive classification formatrix-related mudrock pores. AAPG Bulletin 96, 1071–1098.
| Spectrum of pore types and networks in mudrocks and a descriptive classification formatrix-related mudrock pores.Crossref | GoogleScholarGoogle Scholar |
Mory, A., and Haig, D. W. (2011). ‘Permian-Carboniferous geology of the northern Perth and Southern Carnarvon Basins, Western Australia – a field guide.’ (Department of Mines and Petroleum: Perth, Western Australia.)
Prost, R., Benchara, A., and Huard, E. (1998). State and location of water adsorbed on clay minerals: consequences of the hydration and swelling-shrinkage phenomena. Clays and Clay Minerals 46, 117–131.
| State and location of water adsorbed on clay minerals: consequences of the hydration and swelling-shrinkage phenomena.Crossref | GoogleScholarGoogle Scholar |
Sondergeld, C. H., Newsham, K. E., Comisky, J. T., Rice, M. C., and Rai, C. S.(2010). ‘Petrophysical considerations in evaluating and producing shale gas resources.’ Paper presented at the SPE Unconventional Gas Conference, Pittsburgh, Pennsylvania, USA, 23–25 February 2010. (Society of Petroleum Engineers.)
U.S.Energy Information Administration (2015). ‘Technically recoverable shale oil and shale gas resources: Australia.’ (U.S.Energy Information Administration (EIA). Washington, DC, USA.)
Washburn, K. E. (2014). Relaxation mechanisms and shales. Concepts in Magnetic Resonance Part A 43A, 57–78.
| Relaxation mechanisms and shales.Crossref | GoogleScholarGoogle Scholar |
Washburn, K. E., and Birdwell, J. E. (2013). Updated methodology for nuclear magnetic resonance characterization of shales. Journal of Magnetic Resonance (San Diego, Calif.) 233, 17–28.
| Updated methodology for nuclear magnetic resonance characterization of shales.Crossref | GoogleScholarGoogle Scholar |
