Pore Scale Modeling of Reactive Transport Involved in Geologic CO2 Sequestration

Abstract

We apply a multi-component reactive transport lattice Boltzmann model developed in previolls studies to modeling the injection of a C02 saturated brine into various porous media structures at temperature T=25 and 80°C. The porous media are originally consisted of calcite. A chemical system consisting of Na+, Ca 2 +, Mg2+, H+, CO 2 (aq), and CI-is considered. The fluid flow, advection and diHusion of aqueous species, homogeneous reactions occurring in the bulk fluid, as weB as the dissolution of calcite and precipitation of dolomite are simulated at the pore scale. The effects of porous media structure on reactive transport are investigated. The results are compared with continuum scale modeling and the agreement and discrepancy are discussed. This work may shed some light on the fundamental physics occurring at the pore scale for reactive transport involved in geologic C02 sequestration.

Shale gas and non-aqueous fracturing fluids: Opportunities and challenges for supercritical CO2

“…Lattice Boltzmann models are appropriate tools in simulating these processes since they capture intra-pore geometries, complex flows, and all relevant physicochemical processes. Our LBMs can resolve multiphase flow [42][43][44][65][66][67][68], multi-component chemistry [69][70][71][72][73][74][75][76][77][78], and phase transitions [79]. Fig.…”

A model comparison initiative for a CO2 injection field test: an introduction to Sim-SEQ

“…This is because there are still considerable uncertainties regarding storage capacity, injectivity, caprock integrity, leakage pathways, impact on reservoir rock and formation fluids, and effectiveness of post-injection monitoring of the injected CO 2 plume (Wilson et al, 2007;Stauffer et al, 2009;Li et al, 2011;Seto et al, 2011;Dethlefsen et al, 2012). Convincing scientific research targeted at resolving and quantifying these uncertainties is needed to assure policy makers (and the public in general) that GCS is a viable technology and that it can be deployed with adequate safeguards (Kang et al, 2010).…”

“…Because data from actual field test sites are limited and expensive, scientists and engineers often must rely upon conceptual and numerical models to understand and predict the subsurface movement of the injected CO 2 . These models must account for multiple physicochemical processes involving interactions between the injected CO 2 , the formation fluids (either brine or hydrocarbons), and the reservoir rocks (Kang et al, 2010). Depending upon the nature of the fluids already residing in the formation, these processes may include (but are not necessarily limited to) fluid flow under pressure gradients created by the injection process; buoyancy-driven flow caused by density difference between the injected and formation fluids; diffusion, dispersion and fingering (arising from formation heterogeneities and mobility contrast between the fluids); capillarity (resulting from different wetting characteristics of the fluids concerned); dissolution into the formation fluid, mineralization, and adsorption of CO 2 (Intergovernmental Panel on Climate Change, IPCC, 2005;Mukhopadhyay et al, 2011).…”

Reaction and diffusion at the reservoir/shale interface during CO2 storage: Impact of geochemical kinetics

“…Often reactions in porous rock proceed closer to equilibrium than reactions in the laboratory (Arvidson and Lüttge, 2010). The next source of uncertainty is in upscaling from the pore-grain scale to the level of the representative elemental volume (REV) of the rock (Kang et al, 2010;Li et al, 2007). Uncertainty is also entailed in describing the reactive surface area of minerals -in other words, not all sites on a surface are equally reactive (Gautier et al, 2001;Rimstidt et al, 2012;Washton et al, 2008).…”