InterPore2025

Pore Network Modeling of Coupled Mineral Dissolution and Precipitation in Fractured Porous Media

20 May 2025, 14:50

15m

Oral Presentation (MS25) Advances in Carbon Mineralization: Unveiling Multiscale Geo-processes and Coupled Mechanisms MS25

Speaker

Agnieszka Budek (Department of Earth and Environmental Sciences, University of Minnesota – Twin Cities, Minneapolis, USA)

Description

Understanding the interplay between mineral dissolution and precipitation in fractured porous media is crucial for advancing carbon mineralization processes. Fractures are often expected to act as highways for supplying CO2-charged water, while the matrix is anticipated to serve as a storage space. However, how the interplay between mineral dissolution and precipitation controls mineralization in fractured porous media remains unclear. In this study, we develop a pore network model to investigate coupled dissolution-precipitation reactions within a fracture-matrix system. The dynamic interaction of flow, transport, reactions, and geometry evolution in such systems gives rise to a variety of pattern formation regimes: from rapid fracture passivation to intense side branching and nearly homogeneous transformation of the rock matrix into the product phase. In addition to exploring these regimes, we aim to determine the conditions that optimize precipitate deposition—achieving significant mineralization without causing severe clogging.

Our results reveal that spatial separation between dissolution and precipitation can lead to fracture passivation under specific conditions (see Fig. 1), while rapid precipitation and “in-situ” deposition of secondary material may result in a uniform transformation of the rock matrix (see Fig. 2). Moreover, partial clogging within fractures induces side branching, maximizing precipitation and enabling minerals to deposit deeper into the system (see Fig. 3).

Further, we explore the impact of operationally controllable parameters, such as flow (injection) rate and inlet reactant concentration. The flow rate determines the length and density of side branches, while the inlet concentration governs the rate of fracture passivation. This work provides valuable insights into optimizing carbon mineralization in fractured porous systems, enhancing our understanding of the dynamic processes underlying mineral dissolution, precipitation, and system evolution.