Work

Solute mixing regulates heterogeneity of mineral precipitation in porous media

Year: 2017

Type: article

Abstract: Synchrotron X‐ray microtomography was used to track the spatiotemporal evolution of mineral precipitation and the consequent alteration of the pore structure. Column experiments were conducted by injecting CaCl 2 and NaHCO 3 solutions into granular porous media either as a premixed supersaturated solution (external mixing) or as separate solutions that mixed within the specimen (internal mixing). The two mixing modes produced distinct mineral growth patterns. While internal mixing promoted transverse heterogeneity with precipitation at the mixing zone, external mixing favored relatively homogeneous precipitation along the flow direction. The impact of precipitation on pore water flow and permeability was assessed via 3‐D flow simulations, which indicated anisotropic permeability evolution for both mixing modes. Under both mixing modes, precipitation decreased the median pore size and increased the skewness of the pore size distribution. Such similar pore‐scale evolution patterns suggest that the clogging of individual pores depends primarily on local supersaturation state and pore geometry.

Source: Geophysical Research Letters

DOI: 10.1002/2017gl073999

Authors: Mehmet B. Cil, Minwei Xie, Aaron I. Packman, Giuseppe Buscarnera

Institutions: Northwestern University, Hong Kong University of Science and Technology

Language: English

Topic: CO2 Sequestration and Geologic Interactions

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

Open Access status: green