CO2-brine-caprock interaction: Reactivity experiments on mudstone caprock of South-west Hub geo-sequestration project

Jayasekara, D.W.; Ranjith, P.G.; Wanniarachchi, W.A.M.; Rathnaweera, T.D.; Gent, Dominique Van

doi:10.1016/j.petrol.2020.107011

Cited by 12 publications

(5 citation statements)

References 51 publications

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“…28 The CO 2 solubility at 60 °C and 10 MPa is ∼23 cm 3 (STP) per gram of brine. 29 As a result of the dissolution of minerals such as kaolinite and muscovite, the pore volume of the caprock increases, 30 enhancing its flowability/permeability, 4 which is a disadvantage for caprock performance.…”

Section: Resultsmentioning

confidence: 99%

“…CCS or storing CO 2 in geological formations such as deep saline aquifers appears to be one of the major solutions to the reduction of anthropogenic CO 2 concentration in the atmosphere. , Moreover, the integrity of caprock over geological time scales is the most crucial factor for effective CO 2 storage in deep saline aquifers because it prevents CO 2 back-migration into groundwater bodies . During CO 2 injection, the wetting brine phase is displaced by nonwetting CO 2 , and the injected CO 2 remains in the supercritical state in the reservoir rock due to the aquifer’s high pressure and temperature . Because the viscosity and density of scCO 2 are lower than those of brine, the injected CO 2 tends to move upward and creates buoyancy pressure on the caprock, inducing stress changes .…”

Section: Introductionmentioning

confidence: 99%

“…3 During CO 2 injection, the wetting brine phase is displaced by nonwetting CO 2 , and the injected CO 2 remains in the supercritical state in the reservoir rock due to the aquifer's high pressure and temperature. 4 Because the viscosity and density of scCO 2 are lower than those of brine, the injected CO 2 tends to move upward and creates buoyancy pressure on the caprock, 5 inducing stress changes. 6 If the stress change is sufficient, faults and pre-existing fractures can be reactivated, or new fractures can be created in the caprock.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Geochemical Characteristics on Caprock Performance in Deep Saline Aquifers

Jayasekara

Ranjith

2021

Energy Fuels

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Sequestration of CO2 in deep saline aquifers has attracted positive attention from the scientific community as a mitigatory measure to reduce anthropogenic CO2 in the atmosphere. Caprock layers/zones, which are saturated with brine and CO2 at different degrees of saturation (DOSs), behave differently. Since the risk of CO2 back-migration through different zones in the caprock varies, the focus of this study is on the effects of injected CO2 on the mineralogical and mechanical behavior of caprock with different DOSs due to chemical alteration. A series of reactivity tests were conducted on siltstone samples under different saturation conditions. The experimental results showed that fast dissolution of minerals such as kaolinite and muscovite due to carbonic acid increases the pore volume of caprock. Therefore, flow paths and porosity increase in the fully CO2–brine-saturated zone compared to other zones in the caprock that are not fully saturated with CO2 and brine. In addition, the caprock layer, which is fully saturated with CO2 and brine, has the highest stress corrosion and shear weakening due to mineral dissolution and wetting softening effects, which occur due to surface energy consumption. The next weakest zone in the caprock is the fully brine-saturated siltstone layer due to quartz hydrolysis and wetting softening effects. Therefore, serious attention should be paid to a caprock layer fully saturated with a CO2–brine mixture during sequestration because the risk of CO2 migration via this caprock zone is high, and this affects the permanence and security of injected CO2, especially during periodic CO2 injections and minor seismic events.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of Geochemical Characteristics on Caprock Performance in Deep Saline Aquifers

Jayasekara

Ranjith

2021

Energy Fuels

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“…In energy science, the landmark description of porosity in sedimentary organic matter observed by SEM visualization of ion-milled samples of Barnett Shale 8 resulted in a paradigm-shifting focus on the fluid transport and storage properties of petroliferous mudstones, where SEM visualization is now broadly utilized for understanding fluid generation 9 – 11 , fluid migration 12 , and reservoir storage properties 13 , 14 . Such studies are relevant for carbon sequestration 15 and seal integrity 16 for natural petroleum reservoirs and energy gas storage (e.g., H 2 , CH 4 ). However, because of low atomic density, all sedimentary organic matter types appear similar (black) in electron microscopy 17 – 19 .…”

Section: Introductionmentioning

confidence: 99%

Cathodoluminescence differentiates sedimentary organic matter types

Hackley,

McAleer,

Jubb

et al. 2024

Sci Rep

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High-resolution scanning electron microscopy (SEM) visualization of sedimentary organic matter is widely utilized in the geosciences for evaluating microscale rock properties relevant to depositional environment, diagenesis, and the processes of fluid generation, transport, and storage. However, despite thousands of studies which have incorporated SEM methods, the inability of SEM to differentiate sedimentary organic matter types has hampered the pace of scientific advancement. In this study, we show that SEM-cathodoluminescence (CL) properties can be used to identify and characterize sedimentary organic matter at low thermal maturity conditions. Eleven varied mudstone samples with a broad array of sedimentary organic matter types, ranging from the Paleoproterozoic to Eocene in age, were investigated. Sedimentary organic matter fluorescence intensity and CL intensity showed an almost one-to-one correspondence, with certain exceptions in three samples potentially related to radiolytic alteration. Therefore, because CL emission can be used as a proxy for fluorescence emission from sedimentary organic matter, CL emission during SEM visualization can be used to differentiate fluorescent from non-fluorescent sedimentary organic matter. This result will allow CL to be used as a visual means to quickly differentiate sedimentary organic matter types without employing correlative optical microscopy and could be widely and rapidly adapted for SEM-based studies in the geosciences.

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“…In recent years, the issues of climate change and global warming caused by excessive extraction and utilization of fossil energy have attracted attention from countries all over the world. − Capturing the emitted CO 2 and injecting it underground to storage (CCS) has been confirmed to be an effective way for mitigating the continuous increase of atmosphere CO 2 levels, and the commonly considered formations for CO 2 storage are depleted oil and gas reservoirs, deep saline aquifers, and basalt formations. − Moreover, the technology of injecting CO 2 into coal seams is also a promising approach that can achieve the dual benefits of enhanced coalbed methane recovery and carbon sequestration. − During this process, the wetting characteristics of the coal–water–CO 2 system play a critical role in evaluating the CO 2 injection rate, adsorption, migration, and trapping capacity, and containment security within the coal seams. , The existing literature has revealed that the wettability of the coal is affected by pressure, temperature, and brine salinity. − Furthermore, Sun investigated the coal wettability at in situ pressures of CO 2 using molecular dynamics simulations. They proposed that CO 2 adsorption directly controlled the change in coal wettability until the adsorption of CO 2 reached saturation at high pressure.…”

Section: Introductionmentioning

confidence: 99%

Coal–Fluid Interfacial Tension in the Coal–Water–CO₂ System: Implications for CO₂ Sequestration in Coal Seams

Cui,

Yao,

Liu

et al. 2024

Energy Fuels

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CO2 geological sequestration in coal seams is an effective method for reducing CO2 emissions and enhancing coal-bed methane extraction. In this context, the coal–fluid interfacial tension (γcoal–fluid) is a critical parameter that influences the CO2 injection, fluid distribution, CO2 storage capacity, and containment safety. Especially, the γcoal–fluid cannot be directly measured, and the influencing factors for γcoal–fluid (including γ normalcoal − CO 2 and γcoal–water in the coal–water–CO2 system) were not reported before. In this study, we calculated the γcoal–fluid of different rank coals under different pressures (3–8 MPa) and temperatures (40–70 °C) by using the combination of Young’s equation and Neumann’s equation. The results show that the γ coal − CO 2 of all coal samples decreases with increasing pressure and coal rank, while it increases with increasing temperature. The γcoal–water slightly decreases with increasing temperature. Furthermore, we conducted a comprehensive investigation into the influence mechanism underlying these factors on γcoal–fluid and quantitatively established the γ coal − CO 2 assessment model. Based on this, we also proposed a methodology for determination of the threshold pore size of caprock (TPSC) and evaluation of sealing security. The calculated TPSC decreases with the increase of burial, and a more water-wetting caprock corresponds to a lower TPSC. This study contributes to a deeper understanding of the wetting phenomenon in the coal–water–CO2 system and provides insight into monitoring the safety of CO2 sequestration in coal reservoirs.

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CO2-brine-caprock interaction: Reactivity experiments on mudstone caprock of South-west Hub geo-sequestration project

Cited by 12 publications

References 51 publications

Effect of Geochemical Characteristics on Caprock Performance in Deep Saline Aquifers

Effect of Geochemical Characteristics on Caprock Performance in Deep Saline Aquifers

Cathodoluminescence differentiates sedimentary organic matter types

Coal–Fluid Interfacial Tension in the Coal–Water–CO₂ System: Implications for CO₂ Sequestration in Coal Seams

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CO2-brine-caprock interaction: Reactivity experiments on mudstone caprock of South-west Hub geo-sequestration project

Cited by 12 publications

References 51 publications

Effect of Geochemical Characteristics on Caprock Performance in Deep Saline Aquifers

Effect of Geochemical Characteristics on Caprock Performance in Deep Saline Aquifers

Cathodoluminescence differentiates sedimentary organic matter types

Coal–Fluid Interfacial Tension in the Coal–Water–CO2 System: Implications for CO2 Sequestration in Coal Seams

Contact Info

Product

Resources

About

Coal–Fluid Interfacial Tension in the Coal–Water–CO₂ System: Implications for CO₂ Sequestration in Coal Seams