Using time-lapse seismic to monitor injection of CO2 into a depleted gas reservoir—Otway pilot project*
Milovan Urosevic A , Roman Pevzner B , Valeriya Shulakova C , Anton Kepic D and Sandeep Sharma EA CO2CRC and Curtin University of Technology GPO Box U1987, Perth 6845, WA. Email: M.Urosevic@curtin.edu.au
B CO2CRC and Curtin University of Technology GPO Box U1987, Perth 6845, WA. Email: r.pevzner@curtin.edu.au
C CSIRO and CO2CRC 26 Dick Perry Ave, Kensigton, 6151, WA. Email: Valeriya.Shulakova@csiro.au
D CO2CRC and Curtin University of Technology GPO Box U1987, Perth 6845, WA. Email: A.Kepic@curtin.edu.au
E Schlumberger and CO2CRC 26 Dick Perry Ave, Kensington 6151, WA. Email: Sharma2@slb.com
The APPEA Journal 50(2) 712-712 https://doi.org/10.1071/AJ09076
Published: 2010
Abstract
The CO2CRC Otway Pilot project involves the injection of over 65,000 tonnes of CO2/CH4 gas mixture (80% of carbon dioxide and 20% of methane) into a deep depleted gas reservoir. The test site is located onshore, some 300 km west of Melbourne. CO2 injection into a depleted gas reservoir will provide important experience for monitoring and verification under these conditions.
In this study we address the application of time-lapse seismic for assurance monitoring, which aims to verify that the injected gas remains confined to the target formation. Moreover, we also attempt to image CO2 plume within the reservoir. This is particularly challenging due to the small size of the reservoir and the associated CO2 plume, the presence of residual gas saturation, as well as the significant depth and complexity of the reservoir. In order to meet these challenges we developed a comprehensive seismic monitoring program, which included both time-lapse surface and borehole seismic methods.
Prior to the base line survey, a series of 2D test surveys was conducted that aimed to investigate seismic repeatability at the site. It was crucial to keep the repeatability at the highest level considering that the time-lapse seismic signal was expected to be quite small. In fact, it is widely adopted that injection of CO2 into a depleted gas reservoir or equivalently enhanced methane recovery is not traceable by repeated seismic measurements.
Careful planning of 3D surveys allowed us to achieve excellent repeatability, which is at the reservoir level represented by normalised RMS difference values of about 20%. Single, coherent time-lapse anomaly at the reservoir level was observed; its location and amplitude agree with the position of CO2 plume predicted by reservoir simulations. Measured amplitude differences agreed with the one predicted by seismic modelling.
Keywords: time-lapse, 3D VSP, 3D seismic, CO2 sequestration, Naylor
Milovan Urosevic received BSc (Hons) in geophysics from the University of Belgrade in 1980, MSc in geophysics from the University of Houston in 1985 and PhD in geophysics from the Curtin University of Technology in 2000. He acquired over ten years of industry experience working in areas of seismic data processing, AVO, inversion, application of seismic attributes and seismic anisotropy for rock characterisation. After joining Curtin University in 1991 he has taken part in various industry projects related to the application of high-resolution seismic methods, multi-component seismology, borehole seismic methods, seismic anisotropy, coal and hard rock seismic data processing. Member: ASEG, EAGE and SEG. |
Roman Pevzner graduated from Lomonosov Moscow State University (Russia) in 1999 with degree of BSc in Geology. He got MSc in Geology in 2001 and PhD in Geophysics in 2004 from the same university. Roman was headed the software development department in a geophysical service company for 6 years, since 2002 to 2008. At the same time he was doing research and teaching at LMSU. In 2008 Dr Pevzner was appointed to an Associate Professor position at Curtin University of Technology, Department of Exploration Geophysics. His main areas of interest are signal processing, borehole seismic methods and time-lapse seismic surveys. |
Dr Valeriya Shulakova (CSIRO) obtained her PhD from Moscow State University in geophysics. Her expertise is in signal processing and in particular in time-lapse seismics and 4D seismic data processing. Prior to joining CSIRO in 2008 as a research scientist, she spent over 5 years working for geophysical service companies in Russia in the area of seismic data processing and analysis. |
Dr Anton Kepic obtained his BSc Honours from University of Western Australia in 1988 and his PhD from University of British Columbia in 1995. He is the geophysical program discipline leader within the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC). Anton has over 20 years’ experience in academia and industry. His research interests are in development of new geophysical techniques and methods and design and construction of specialised geophysical instrumentation. |
Mr Sharma is the Program Manager Pilot and Demonstration Program, with the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), Australia, managing the Otway Basin Pilot Geo-sequestration Program. He is on partial secondment to the CO2CRC from Schlumberger starting January 2005. In Schlumberger since 1981, he has worked across the globe and held a wide variety of senior positions in operations management, marketing and new product development. Mr Sharma has a Bachelors in Electrical Engineering (India), a Post Graduate Diploma in Business Management (UK), a Masters in Sustainability Management (Australia) and has been a visiting fellow of the Sloan School, MIT (USA). |
References
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Urosevic, M., Pevzner, R., Kepic, A., Shulakova, V., Wisman, P., and Sharma, S. (2010). Time-lapse seismic monitoring of CO2 injection into a depleted gas reservoir—Naylor Field, Australia. The Leading Edge 29, 936–41.
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