The DAS observations also revealed the seismogenic fault below the surface, which was not captured in earlier seismic images. DAS is the optimal technology for such conditions." Otherwise, deployment and demobilization of the array for each active seismic survey would be prohibitively costly and cause too much interruption to the land owners. "To enable the long-term monitoring, we had to use a permanent downhole installation of the seismic sensors. Part of the focus of the Stage 3 injection was to look more closely at potential cost-effective, long-term monitoring of geological carbon storage, said Glubokovskikh. They detected 17 tiny seismic events during that period, with a maximum magnitude of 0.1.Īn earlier "Stage 2C" CO 2 injection at the site, of the same size, was monitored at the time using geophones buried below the surface that detected several microseismic events. The seismic monitoring system was designed by a group of geophysicists at Curtin University in Perth, Australia, led by Roman Pevzner and Boris Gurevich, to rely on five deep boreholes outfitted with sensitive fiber optic cable to monitor a 15,000 metric ton CO 2 injection, called Stage 3, at the Otway site over 610 days. "It is hard to think of another practical monitoring system apart from the multi-well DAS vertical seismic profiling which could provide such temporal and spatial resolution for a small CO 2 plume." ![]() "We relied on the frequent snapshots of the storage formation to relate the CO 2 plume evolution to induced seismicity," he added. "As far as we know, the Otway Project remains the only CO 2 storage project where induced seismicity was at the very least coincident with the saturation front movement, not the pressure front," said study lead author Stanislav Glubokovskikh of Lawrence Berkeley National Laboratory. However, there is a risk of induced earthquakes after gigatons of carbon dioxide will be injected within the same geologic basin by multiple storage projects over decades of operations, and scientists would like to better understand how this seismicity is triggered and how it evolves over time.Īmong the interesting details uncovered by the new DAS deployment at Otway: the tiny earthquakes that accompanied two injection phases at the site appear to follow the saturation front of the CO 2 plume within the rock, rather than the pressure front from injection. ![]() The CO2CRC Otway Project in Victoria is a research test site for the subsurface storage of carbon dioxide, as one possible way to reduce the impacts of climate-warming carbon emissions.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |