CO2‐Saturated Brine Injection Into Unconsolidated Sandstone: Implications for Carbon Geosequestration
MetadataShow full item record
Copyright © 2019 American Geophysical Union
©2019. American Geophysical Union. All Rights Reserved. Carbon dioxide (CO2) injection into deep depleted hydrocarbon reservoirs or saline aquifers is currently considered the best approach to large-scale CO2 storage. Importantly, the pore structure and permeability of the storage rock are affected by fines release, migration, and reattachment in the initial stage of CO2 injection, especially in unconsolidated sandstone reservoirs. It is thus necessary to better understand the pore structure changes and the associated permeability evolution during and after CO2 injection. We thus imaged an unconsolidated sandstone at reservoir conditions before and after CO2-saturated brine (“live brine”) injection in situ via X-ray microcomputed tomography to explore the effects of fines migration and mineral dissolution induced by CO2 injection. We found that in the examined sample, large pores dominated the total porosity, and porosity slightly increased after live-brine flooding. Moreover, and importantly, the pore structure changed significantly: large pores were further enlarged while small pores shrank or even disappeared. These structural changes in the tested sample were caused by mobilized fines due to the high-fluid interstitial velocity, which eventually reattached to the grains further downstream. Furthermore, the impact of the pore structural changes on permeability were analyzed in detail numerically. These permeability results are consistent with a fines migration mechanism where reattached fines block pore throats and thus decrease permeability drastically. We therefore can conclude that live brine injected into the examined unconsolidated sandstone will slightly improve storage space (porosity slightly increased); however, injectivity may be severely impaired by the permeability reduction.
Showing items related by title, author, creator and subject.
Yu, H.; Zhang, Y.; Lebedev, Maxim; Wang, Z.; Verrall, M.; Iglauer, Stefan (2019)© Copyright 2018, Society of Petroleum Engineers. Carbon dioxide (CO2) inject to the saline aquifers are general considered as the best candidates for large-scale storage and CO2 enhance oil recovery. The pore structure ...
Experimental evaluation of carbonated brine-limestone interactions under reservoir conditions-emphasis on the effect of core scale heterogeneitiesKhather, M.; Saeedi, Ali; Rezaee, M. Reza; Noble, R. (2018)CO 2 injection into deep geological structures is very often accompanied by chemical interactions between the host rock and injected fluids and/or the in-situ created solute (i.e. carbonated brine). In fact, the in-situ ...
Xie, Sam; Saeedi, Ali; Delle Piane, C.; Esteban, L.; Brady, P. (2017)The South West Hub project is one of the Australian Flagship Carbon Capture and Storage projects located in the south-west of Western Australia. To evaluate the injectivity potential during the forthcoming full-scale CO2 ...