Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity

Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity

NMR Relaxation of Gas Adsorbed in Microporous Material

NMR relaxometry has been widely applied to characterize fluid confined in porous media because of its versatility, chemical selectivity, and noninvasive nature. Here we extend its usage to gas adsorbed in microporous materials by establishing a new quantitative model based on the molecular level NMR relaxation mechanism revealed by the molecular simulation of a prototypical adsorption system, CH4 adsorbed in ZIF-8. The model enables new NMR relaxometry-based characterization methods for thermodynamic, dynamic, and structural properties of adsorption systems, as demonstrated and validated by the experiments where the adsorption capacity and self-diffusivity of H2, CH4, and small alcohols adsorbed in ZIF-8 are deduced from the NMR relaxation data. The findings can serve for a better understanding of the composition–structure–properties relationships of a wide range of adsorption systems which is essential for the development and application of new functional microporous materials

Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity

Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity

Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity

Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity

Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity

Pore-Scale Experimental Investigation of the Effect of Supercritical CO₂ Injection Rate and Surface Wettability on Salt Precipitation

Injectivity is one of the most important factors to evaluate the feasibility of CO2 geological storage. Salt precipitation due to the mass of dry CO2 injected into a saline reservoir may cause a significant decrease in injectivity. However, the coupling effect of injection parameters and reservoir conditions on salt precipitation is not clear. Here, we conducted pore-scale visualization experiments to study the morphology and distribution of salt precipitation in porous structures and their effects on permeability reduction. The experimental results are achieved by controlling the supercritical CO2 injection rate and the surface wettability at the reservoir temperature and pressure. It is found that for hydrophilic and neutral porous surfaces, ex situ precipitation occurs and blocks the entirety of pore throats and bodies, which results in a significant reduction in permeability. Increasing the CO2 injection rate can suppress the capillary reflow and prevent the permeability reduction. For a hydrophobic porous surface, in situ precipitation occurs and occupies much smaller pore volume, which has a slight effect on permeability reduction compared to the hydrophilic samples at the same injection rate. Increasing the CO2 injection rate and dewetting the injection well and formation nearby reduce the possibility of salt accumulation, which has less effect on CO2 injectivity