Pore‐scale investigation of effects of heterogeneity on CO₂ geological storage using stratified sand packs

Abstract

The geological sequestration of CO2 is considered to have great potential. However, the heterogeneity that characterizes most geological reservoirs significantly affects the migration, trapping, and leakage of CO2. The present study involved a pore‐scale investigation of the effects of heterogeneity in pore size and wettability using stratified sand packs. A stratified glass bead (BZ06+BZ02) pack and a quartz+dolomite pack were introduced in flow experiments at gaseous CO2 (gCO2) and supercritical CO2 (scCO2) conditions. Different injection rates, namely, 0.1, 0.3, and 0.6 mL/min, were applied to the drainage while a constant rate of 0.1 mL/min was maintained for the imbibition. High resolution CT imaging and subsequent processing of the images were used to analyze the effects of heterogeneity in pore size and wettability. The results indicate that heterogeneity in pore size and wettability alters the intrinsic percolation abilities of the individual layers of the stratified structure and weaken the linear correlation between CO2 volume and slice‐averaged porosity. It was also observed that water films sometimes exist in the layers with smaller pore spaces after drainage and it can trigger snap off events. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

Pore-scale numerical simulation of supercritical CO2 migration in porous and fractured media saturated with water

“…13). The viscous fingering of scCO 2 becomes much obvious under high injection rates as viscous forces also become more significant (Lv et al, 2017). The CO 2 saturation with time is positive related with the CO 2 injection rates at the inlet (Fig.…”

“…The variation of the grain shapes in porous media, which results in the reservoir heterogeneity (Sun and Bryant, 2014), will accordingly change the spatial distribution of scCO 2 migration paths as the intrinsic permeability of rock also changes (Lv et al, 2017). Based on microscopic observations of thinsections, the sandstone is usually characterized with grains of irregular geometry, which greatly increases the tortuosity of fluid flow.…”

Visual investigation of CO2 dissolution and convection in heterogeneous porous media at reservoir temperature and pressure conditions

“…Original Research Article: Visual investigation of CO 2 dissolution and convection decreases vice versa when CO 2 pass through layers with decreasing permeability. Several other authors also have conducted the effects of heterogeneity for CO 2 convection [30][31][32][33] and trapping [34][35][36] in water using different mimic fluids and different type of porous medium.…”

The impact of permeability heterogeneity on water-alternating-gas displacement in highly stratified heterogeneous reservoirs

“…The dominating mechanisms of miscible gas flooding to improve oil recovery are lowering interfacial, reducing oil viscosity and increasing capillary number (He et al 2018;Li et al 2016Li et al , 2020Lv et al 2017).…”