![]() ![]() Artificial conditions are imposed to accelerate the process however, using reservoir conditions is desirable. 2016), which is not consistent with MT taking place on the hundreds to thousands of years post-injection time scale. Experimental work on core flooding and associated chemical reactions is in practice limited to short time scales of days to months (Perrin et al. In order to deduce the viability of MT in a given geological formation, it is necessary to investigate the carbonate precipitation process at the pore scale and over time periods which are relevant for the slow reaction rates involved in the system (Espinoza et al. 2019) understanding of the influence of tortuosity on precipitation is lacking. While the impact of precipitation on tortuosity has been investigated (Xie et al. 2013 Berg and Held 2016) and influence on permeability (de Lima and Niwas 2000 Gouze and Luquot 2011 Berg 2014 Cai et al. Tortuosity is one characteristic of interest due to its close relationship with porosity (Zhang and Knackstedt 1995 de Lima and Niwas 2000 Pape et al. In addition to investigating the influence of reaction parameters we aim to use this model to investigate if further geophysical properties contribute significantly to the effectiveness of artificially driven mineral precipitation in a subsurface reservoir. We present a method of using these high resolution images, reconstructed in 3D, as physical domains for numerical flow modelling to take place in. 2021), we are able to explore possible CCS reservoir rocks at appropriate resolutions for examining the intricacies of the pore space geometries. 2013 Jiang and Tsuji 2014 Bultreys et al. ![]() Using the popular technique of X-ray micro-computed tomography ( \(\upmu\)CT) for digital image analysis of geological material (Blunt et al. ![]() In order to offset the current global CO \(_\) precipitation at the fluid–solid interface in a true 3D pore geometry. In a fully connected pore network preferential flow pathways still form which results in uneven precipitate distribution.Ī pore network tortuosity of <2 is recommended to facilitate greater carbon mineralisation.Įvaluation of geological formations as potential carbon capture and storage (CCS) reservoirs is of utmost importance for attempting to address the current global climate challenge. The rate of reaction has a stronger influence on mineral precipitation than the amount of available reactant. We also show that the dominant influence on precipitated mass is the Damköhler number, or reaction rate, rather than the availability of reactive minerals, suggesting that this should be the focus when engineering effective subsurface carbon storage reservoirs for long term security. We suggest that a tortuosity of less than 2 is critical in promoting greater precipitation per unit volume and should be considered alongside porosity and permeability when assessing reservoirs for geological carbon storage (GCS). We find evidence that a greater tortuosity, greater degree of branching of a pore network and narrower pore throats are detrimental to MT and contribute to the risk of clogging and reduction of connected porosity. ![]() Using this model, we investigate the impact of pore geometry features such as branching, tortuosity and throat radii on the distribution and occurrence of carbonate precipitation in different pore networks over 2000 year simulated periods. We present a finite elements advection–diffusion–reaction numerical model which uses true pore geometry model domains generated from \(\upmu\)CT imaging. The processes behind MT fundamentally occur at the pore scale, therefore understanding which factors control MT at this scale is crucial. Mineral trapping (MT)is the most secure method of sequestering carbon for geologically significant periods of time. ![]()
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