Halite precipitates as porous crystalline networks, not dispersed crystals: Self-enhancing growth mechanisms during CO₂ storage in saline aquifers
4 affiliations
- 1Environmental Geosciences, Department of Geosciences, University of Oslo, PO Box 1047, Blindern, 0316, Oslo, Norway
- 2Applied Geoscience Department, SINTEF Industry, 7465, Trondheim, Norway
- 3Universite de Pau et des Pays de l'Adour, CNRS, LFCR, Pau, France
- 4Universite de Pau et des Pays de l'Adour, CNRS, DMEX, Pau, France
Abstract
Salt precipitation during CO₂ injection into saline aquifers obstructs flow-controlling pore throats and reduces injectivity, yet reactive transport models assume dispersed, non-porous crystals with negligible fluid flow impact. Here, we demonstrate that halite develops three-dimensional porous networks with 40 ± 15% internal porosity through self-enhancing growth mechanisms. Time-lapse X-ray micro-computed tomography and spectral imaging reveal preferential nucleation at gas-liquid interfaces, where porous hydrophilic aggregates generate capillary suction that draws brine films toward precipitation sites, thereby accelerating growth and expanding the reactive surface area in a positive feedback loop. Spectral tomography identifies two-stage precipitation: dense macrocrystalline cores formed under moderate supersaturation and evaporation, surrounded by microcrystalline overgrowths from rapid late-stage dynamics that produce umbrella-like crusts encapsulating residual brine. This porous architecture explains why modest bulk porosity reduction causes disproportionate permeability decline, as aggregates preferentially obstruct flow percolation pathways rather than uniformly cementing grains or filling pore space. Five interconnected mechanisms drive self-enhancing growth across nano- to centimeter scales: interface nucleation, secondary porous structure formation, steep concentration gradients, hydrophilic substrate film maintenance, and capillary-driven solute delivery. Pore network quantification delivers the first three-dimensional structural characterization of halite growth architecture under GCS-relevant conditions, resolving pore diameter distributions of 20–200 μm, mean coordination numbers of 5, and reactive surface areas averaging 0.04 mm 2 per pore – parameters currently absent from reactive transport models yet essential for predicting injectivity impairment and containment integrity at operational storage scales.
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BibTeX
@article{nooraiepour2026halite,
title = {{Halite precipitates as porous crystalline networks, not dispersed crystals: Self-enhancing growth mechanisms during CO₂ storage in saline aquifers}},
author = {Mohammad Nooraiepour and Mohammad Masoudi and Hannelore Derluyn and Pascale Sénéchal and Peter Moonen and Helge Hellevang},
journal = {Chemical Engineering Journal},
year = {2026},
month = jun,
doi = {10.1016/j.cej.2026.178165},
url = {https://doi.org/10.1016/j.cej.2026.178165},
note = {CC BY},
}
RIS
TY - JOUR
TI - Halite precipitates as porous crystalline networks, not dispersed crystals: Self-enhancing growth mechanisms during CO₂ storage in saline aquifers
AU - Mohammad Nooraiepour
AU - Mohammad Masoudi
AU - Hannelore Derluyn
AU - Pascale Sénéchal
AU - Peter Moonen
AU - Helge Hellevang
PY - 2026
DA - 2026/06/07
JO - Chemical Engineering Journal
DO - 10.1016/j.cej.2026.178165
UR - https://doi.org/10.1016/j.cej.2026.178165
AB - Salt precipitation during CO₂ injection into saline aquifers obstructs flow-controlling pore throats and reduces injectivity, yet reactive transport models assume dispersed, non-porous crystals with negligible fluid flow impact. Here, we demonstrate that halite develops three-dimensional porous networks with 40 ± 15% internal porosity through self-enhancing growth mechanisms. Time-lapse X-ray micro-computed tomography and spectral imaging reveal preferential nucleation at gas-liquid interfaces, where porous hydrophilic aggregates generate capillary suction that draws brine films toward precipitation sites, thereby accelerating growth and expanding the reactive surface area in a positive feedback loop. Spectral tomography identifies two-stage precipitation: dense macrocrystalline cores formed under moderate supersaturation and evaporation, surrounded by microcrystalline overgrowths from rapid late-stage dynamics that produce umbrella-like crusts encapsulating residual brine. This porous architecture explains why modest bulk porosity reduction causes disproportionate permeability decline, as aggregates preferentially obstruct flow percolation pathways rather than uniformly cementing grains or filling pore space. Five interconnected mechanisms drive self-enhancing growth across nano- to centimeter scales: interface nucleation, secondary porous structure formation, steep concentration gradients, hydrophilic substrate film maintenance, and capillary-driven solute delivery. Pore network quantification delivers the first three-dimensional structural characterization of halite growth architecture under GCS-relevant conditions, resolving pore diameter distributions of 20–200 μm, mean coordination numbers of 5, and reactive surface areas averaging 0.04 mm 2 per pore – parameters currently absent from reactive transport models yet essential for predicting injectivity impairment and containment integrity at operational storage scales.
SN - 1385-8947
SN - 1873-3212
ER -