Title: Imaging and quantification of spreading and trapping of carbon dioxide in saline aquifers using meter-scale laboratory experiments

Abstract

The role of capillary forces during buoyant migration of CO₂ is critical toward plume immobilization within the postinjection phase of a geological carbon sequestration operation. However, the inherent heterogeneity of the subsurface makes it very challenging to evaluate the effects of capillary forces on the storage capacity of these formations and to assess in situ plume evolution. To overcome the lack of accurate and continuous observations at the field scale and to mimic vertical migration and entrapment of realistic CO₂ plumes in the presence of a background hydraulic gradient, we conducted two unique long-term experiments in a 2.44 m × 0.5 m tank. X-ray attenuation allowed measuring the evolution of a CO₂ -surrogate fluid saturation, thus providing direct insight into capillarity-dominated and buoyancy-dominated flow processes occurring under successive drainage and imbibition conditions. The comparison of saturation distributions between two experimental campaigns suggests that layered-type heterogeneity plays an important role on nonwetting phase (NWP) migration and trapping, because it leads to (i) longer displacement times (3.6 months versus 24 days) to reach stable trapping conditions, (ii) limited vertical migration of the plume (with center of mass at 39% versus 55% of aquifer thickness), and (iii) immobilization of a larger fraction ofmore » injected NWP mass (67.2% versus 51.5% of injected volume) as compared to the homogenous scenario. Finally, while these observations confirm once more the role of geological heterogeneity in controlling buoyant flows in the subsurface, they also highlight the importance of characterizing it at scales that are below seismic resolution (1–10 m).« less

Authors:

Trevisan, Luca  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-7172-5020"

Pini, Ronny  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-9443-3573"

Cihan, Abdullah ^[3]; Birkholzer, Jens T. ^[3]; Zhou, Quanlin  ^[3];

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• Search DOE PAGES for ORCID "0000-0001-6780-7536"

González-Nicolás, Ana ^[4]; Illangasekare, Tissa H. ^[5]

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+ Show Author Affiliations

1. Colorado School of Mines, Golden, CO (United States). Center for Experimental Study of Subsurface Environmental Processes, Dept. of Civil and Environmental Engineering; Univ. of Texas, Austin, TX (United States). Gulf Coast Carbon Center, Bureau of Economic Geology, Jackson School of Geosciences
2. Colorado School of Mines, Golden, CO (United States). Dept. of Petroleum Engineering; Imperial College, London (United Kingdom). Dept. of Chemical Engineering
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Geosciences Division
4. Colorado School of Mines, Golden, CO (United States). Center for Experimental Study of Subsurface Environmental Processes, Dept. of Civil and Environmental Engineering; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Geosciences Division
5. Colorado School of Mines, Golden, CO (United States). Center for Experimental Study of Subsurface Environmental Processes, Dept. of Civil and Environmental Engineering

Publication Date:

Tue Dec 27 00:00:00 EST 2016

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC); National Science Foundation (NSF)

OSTI Identifier:

1393603

Grant/Contract Number:  

AC02-05CH11231; FE0004630; EAR-1045282

Resource Type:

Accepted Manuscript

Journal Name:

Water Resources Research

Additional Journal Information:

Journal Volume: 53; Journal Issue: 1; Journal ID: ISSN 0043-1397

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; surrogate fluids; sandbox experiments; migration and trapping; injection schemes; geological carbon storage; heterogeneity