TY - JOUR
T1 - Analysis of microseismicity and reactivated fault size to assess the potential for felt events by co2 injection in the illinois basin
AU - Williams-Stroud, Sherilyn
AU - Bauer, Robert
AU - Leetaru, Hannes
AU - Oye, Volker
AU - Stanek, Frantisek
AU - Greenberg, Sallie
AU - Langet, Nadege
N1 - Funding Information:
Geological Sequestration Consortium at the Illinois State Geological Survey (ISGS) with funding from the U.S. Department of Energy— National Energy Technology Laboratory. Nearly 1 million tonnes of CO2 were injected into the base of a 500 m thick saline sandstone reservoir at a depth of 2140 m for more than 3 yr from November 2011 to 2014 in the CCS1 well. Prior to injection, an extensive inves- tigation of site conditions included monitoring of air, soil, groundwater, and bedrock. Monitoring activities are sched- uled to continue into the first quarter of 2021. A second injec- tion well, CCS2, part of the IL-ICCS project, was brought online in April 2017. As a result, data collection also encom- passes induced seismicity related to the IL-ICCS indus- trial-scale demonstration project. Injection in the CCS2 well is scheduled to take place for 3 yr or longer, with a total injection volume target of up to 5 million tonnes, and its average rate to date is about 570;000 tonnes=yr.
Funding Information:
This project is funded by the U.S. Department of Energy through the National Energy Technology Laboratory (NETL), under Agreement DE-FC26-05NT42588, and by CLIMIT (a Norwegian national program that provides financial support for research, development and demonstration of CCS technologies) and the Norwegian Research Council. The authors would like to thank the U.S. Geological Survey (USGS) for providing their event catalog and useful discussions concerning the data. Expert reprocessing of the 3D seismic volume was done by Sterling Seismic Services, and the authors wish to thank them for informative discussions on their seismic reprocessing results. The authors would like to thank Petroleum Experts Ltd. for their kind donation of the MOVE structural analysis software suite used in this study. The authors would also like to thank Schlumberger for their donation of Petrel software, which was used to model and analyze the seismic data for this project.
Publisher Copyright:
© Seismological Society of America.
PY - 2020/10
Y1 - 2020/10
N2 - The results of monitoring of carbon dioxide (CO2 ) injection at the Illinois Basin—Decatur Project (IBDP) and the companion Illinois Industrial Carbon Capture and Sequestration Sources (IL-ICCS) project—have shown that reservoir response to fluid pressure changes can vary significantly at different injection locations within the same reservoir. Predrill reservoir characterization is important to identify potentially seismogenic faults. However, interpretations of newly reprocessed 3D seismic reflection data illustrate the challenges related to their identification in a region dominated by faulting with small vertical offsets. Faults interpreted in the 3D seismic volume range from ∼ 300 to 1200 m wide and are in the same size range as faults that could have been the source of historical events up to Mw 2.7 in central Illinois. The array of monitoring sensors that was installed for the IBDP continues to collect data, as injection operates in IL-ICCS, the second injection well. CO2 injection rates for the IL-ICCS well are on average 1.7 times the rates injected in the IBDP well, but a significantly reduced rate of induced seismicity is observed. This article presents results of passive seismic monitoring for the duration of the project to date, integrating active and passive seismic data to develop a new interpretation of the subsurface structure at the Decatur site that explicitly identifies pathways for fluid flow into the basement leading to induced seismicity, and provides a geological explanation for the sharp reduction of induced seismicity during injection at higher rates into the second well. The use of seismic moment to estimate the length of seismogenic slip planes in the local subsurface suggests that faults large enough to produce felt seismicity are unlikely to be present at or near the Decatur site.
AB - The results of monitoring of carbon dioxide (CO2 ) injection at the Illinois Basin—Decatur Project (IBDP) and the companion Illinois Industrial Carbon Capture and Sequestration Sources (IL-ICCS) project—have shown that reservoir response to fluid pressure changes can vary significantly at different injection locations within the same reservoir. Predrill reservoir characterization is important to identify potentially seismogenic faults. However, interpretations of newly reprocessed 3D seismic reflection data illustrate the challenges related to their identification in a region dominated by faulting with small vertical offsets. Faults interpreted in the 3D seismic volume range from ∼ 300 to 1200 m wide and are in the same size range as faults that could have been the source of historical events up to Mw 2.7 in central Illinois. The array of monitoring sensors that was installed for the IBDP continues to collect data, as injection operates in IL-ICCS, the second injection well. CO2 injection rates for the IL-ICCS well are on average 1.7 times the rates injected in the IBDP well, but a significantly reduced rate of induced seismicity is observed. This article presents results of passive seismic monitoring for the duration of the project to date, integrating active and passive seismic data to develop a new interpretation of the subsurface structure at the Decatur site that explicitly identifies pathways for fluid flow into the basement leading to induced seismicity, and provides a geological explanation for the sharp reduction of induced seismicity during injection at higher rates into the second well. The use of seismic moment to estimate the length of seismogenic slip planes in the local subsurface suggests that faults large enough to produce felt seismicity are unlikely to be present at or near the Decatur site.
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U2 - 10.1785/0120200112
DO - 10.1785/0120200112
M3 - Article
AN - SCOPUS:85092059441
SN - 0037-1106
VL - 110
SP - 2188
EP - 2204
JO - Bulletin of the Seismological Society of America
JF - Bulletin of the Seismological Society of America
IS - 5
ER -