Enhancing residual trapping of supercritical CO2 via cyclic injections

Date

2016

Authors

Herring, Anna
Andersson, Linnea
Wildenschild, Dorthe

Journal Title

Journal ISSN

Volume Title

Publisher

American Geophysical Union

Abstract

We utilize synchrotron X-ray tomographic imaging to investigate the pore-scale characteristics and residual trapping of supercritical CO2 (scCO2) over the course of multiple drainage-imbibition (D-I) cycles in Bentheimer sandstone cores. Capillary pressure measurements are paired with X-ray image-derived saturation and connectivity metrics which describe the extent of drainage and subsequent residual (end of imbibition) scCO2 trapping. For the first D-I cycle, residual scCO2 trapping is suppressed due to high imbibition capillary number (Ca ≈ 10−6); however, residual scCO2 trapping dramatically increases for subsequent D-I cycles carried out at the same Ca value. This behavior is not predicted by conventional multiphase trapping theory. The magnitude of scCO2 trapping increase is hysteretic and depends on the relative extent of the sequential drainage processes. The hysteretic pore-scale behavior of the scCO2-brine-sandstone system observed in this study suggests that cyclic multiphase flow could potentially be used to increase scCO2 trapping for sequestration applications.

Description

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Citation

Source

Geophysical Research Letters

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

DOI

10.1002/2016GL070304

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