Minerals

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22 pages, 11965 KiB

Open AccessArticle

CO₂ Leakage Scenarios in Shale Overburden

by Gilda Currenti, Barbara Cantucci, Giordano Montegrossi, Rosalba Napoli, M. Shahir Misnan, M. Rashad Amir Rashidi, Zainol Affendi Abu Bakar, Zuhar Zahir Tuan Harith, Nabila Hannah Samsol Bahri and Noorbaizura Hashim

Minerals 2023, 13(8), 1016; https://doi.org/10.3390/min13081016 - 29 Jul 2023

Cited by 2 | Viewed by 906

Abstract

Potential CO₂ leakage from deep geologic reservoirs requires evaluation on a site-specific basis to assess risk and arrange mitigation strategies. In this study, a heterogeneous and realistic numerical model was developed to investigate CO₂ migration pathways and uprising time in a [...] Read more.

Potential CO₂ leakage from deep geologic reservoirs requires evaluation on a site-specific basis to assess risk and arrange mitigation strategies. In this study, a heterogeneous and realistic numerical model was developed to investigate CO₂ migration pathways and uprising time in a shaly overburden, located in the Malaysian off-shore. Fluid flow and reactive transport simulations were performed by TOUGHREACT to evaluate the: (1) seepage through the caprock; (2) CO₂-rich brine leakage through a fault connecting the reservoir with seabed. The effect of several factors, which may contribute to CO₂ migration, including different rock types and permeability, Fickian and Knudsen diffusion and CO₂ adsorption in the shales were investigated. Obtained results show that permeability mainly ruled CO₂ uprising velocity and pathways. CO₂ migrates upward by buoyancy without any important lateral leakages due to poor-connection of permeable layers and comparable values of vertical and horizontal permeability. Diffusive flux and the Knudsen flow are negligible with respect to the Darcy regime, despite the presence of shales. Main geochemical reactions deal with carbonate and pyrite weathering which easily reach saturation due to low permeability and allowing for re-precipitation as secondary phases. CO₂ adsorption on shales together with dissolved CO₂ constituted the main trapping mechanisms, although the former represents likely an overestimation due to estimated thermodynamic parameters. Developed models for both scenarios are validated by the good agreement with the pressure profiles recorded in the exploration wells and the seismic data along a fault (the F05 fault), suggesting that they can accurately reproduce the main processes occurring in the system. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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19 pages, 3701 KiB

Open AccessArticle

The Power of Characterizing Pore-Fluid Distribution for Microscopic CO₂ Injection Studies in Tight Sandstones

by Hamad AlKharraa, Karl-Heinz Wolf, Abdulrahman AlQuraishi, Mohamed Mahmoud, Mohammed AlDuhailan and Pacelli Zitha

Minerals 2023, 13(7), 895; https://doi.org/10.3390/min13070895 - 30 Jun 2023

Viewed by 991

Abstract

The microscopic structure of low-permeability tight reservoirs is complicated due to diagenetic processes that impact the pore-fluid distribution and hydraulic properties of tight rocks. As part of an ongoing study of carbon dioxide-enhanced oil and gas recovery (CO₂-EOR/EGR) and CO₂ [...] Read more.

The microscopic structure of low-permeability tight reservoirs is complicated due to diagenetic processes that impact the pore-fluid distribution and hydraulic properties of tight rocks. As part of an ongoing study of carbon dioxide-enhanced oil and gas recovery (CO₂-EOR/EGR) and CO₂ sequestration, this research article adopts an integrated approach to investigate the contribution of the micropore system in pore-fluid distribution in tight sandstones. A new dimensionless number, termed the microscopic confinement index (MCI), was established to select the right candidate for microscopic CO₂ injection in tight formations. Storativity and containment indices were essential for MCI estimation. A set of experiments, including routine core analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), mercury injection capillary pressure (MICP), and nuclear magnetic resonance (NMR), was performed on three tight sandstone rock samples, namely Bandera, Kentucky, and Scioto. Results indicate that the presence of fibrous illite acting as pore bridging in Bandera and Kentucky sandstone samples reduced the micropore-throat proportion (MTMR), leading to a significant drop in the micropore system confinement in Kentucky and Bandera sandstone samples of 1.03 and 0.56, respectively. Pore-filling kaolinite booklets reduced the micropore storativity index (MSI) to 0.48 in Kentucky and 0.38 in Bandera. On the other hand, the absence of fibrous illite and kaolinite booklets in Scioto sandstone led to the highest micropore system capability of 1.44 MTMR and 0.5 MSI to store and confine fluids. Therefore, Scioto sandstone is the best candidate for CO₂ injection and storage among the tested samples of 0.72 MCI. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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14 pages, 2323 KiB

Open AccessArticle

Geochemical Modeling of Changes in Storage Rock Environments at CO₂ Injection Sites

by Monika Licbinska, Lenka Mertova, Nada Rapantova and Katerina Stejskalova

Minerals 2023, 13(2), 298; https://doi.org/10.3390/min13020298 - 20 Feb 2023

Viewed by 1331

Abstract

Geochemical modeling in TOUGHREACT code was used to simulate chemical processes in CO₂–rock–brackish water systems in a pilot research environment of CO₂ storage in the Brodske area (Czech Republic). Models studied mineralogical changes in rock samples resulting from acidification of [...] Read more.

Geochemical modeling in TOUGHREACT code was used to simulate chemical processes in CO₂–rock–brackish water systems in a pilot research environment of CO₂ storage in the Brodske area (Czech Republic). Models studied mineralogical changes in rock samples resulting from acidification of the aqueous phase caused by the dissolution of pressurized supercritical CO₂. Rock samples of the reservoir horizon and cement from the grouting of an injection borehole were considered, and the water phase represented the mineralized groundwater. The aim of the study was to characterize the influence of CO₂ in the geological structure on mineralogical rock changes and to predict gas distribution through the rocks bearing brackish water. The most important chemical processes are dissolution of carbonates and clay minerals during the injection of CO₂ into the structure, as the increase in porosity in the structure affects the sequestration capacity of the reservoir rock. In the CO₂–cement–brackish water system, the models confirm the rapid dissolution of portlandite and its replacement with calcite. The CSH gel is also dissolved, and silica gel appears. The porosity of the cement decreases. Further studies on such a cement slurry are needed to prevent the possibility of mechanical damage to the integrity of the borehole. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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18 pages, 3239 KiB

Open AccessArticle

CO₂ Dipole Moment: A Simple Model and Its Implications for CO₂-Rock Interactions

by Massimo Calcara and Matteo Caricaterra

Minerals 2023, 13(1), 87; https://doi.org/10.3390/min13010087 - 06 Jan 2023

Cited by 2 | Viewed by 11423

Abstract

CO₂ is a widespread fluid naturally occurring within the Earth crust or injected in deep strata for technological issues such as Carbon Capture and Storage (CCS). At STP conditions, CO₂ is a gas, with a net zero dipole moment. Growing pressures [...] Read more.

CO₂ is a widespread fluid naturally occurring within the Earth crust or injected in deep strata for technological issues such as Carbon Capture and Storage (CCS). At STP conditions, CO₂ is a gas, with a net zero dipole moment. Growing pressures produce an increase in its density. The reduced intermolecular distance causes a variation in the molecular structure, due to the intensification of mutual interactions. Some published spot data reveal the departure from the planarity of the bond angle while others provide few values of the CO₂ dipole moment. Based on a small amount of literature-measured angle values, it was possible first to extrapolate a correlation between bond angle and density (R² = 0.879). By fixing the partial charges distribution, we present a simple model that allows the calculation of the CO₂ dipole moment directly from the geometry of the molecule, in the range of 179–162 degrees, 1-degree step. Results give values up to about 1 D. Being aware that this model is qualitative, it gives, however, an explanation of the experimental reactivity, and it also provides a valid tool in identifying zones in the crust where these reactions are likely to occur efficiently. Finally, we hypothesise the role of dry CO₂ in the carbonate formation through the interactions with the basalts. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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21 pages, 10976 KiB

Open AccessArticle

CO₂ Reaction-Diffusion Experiments in Shales and Carbonates

by Giordano Montegrossi, Barbara Cantucci, Monica Piochi, Lorenzo Fusi, M. Shahir Misnan, M. Rashad Amir Rashidi, Zainol Affendi Abu Bakar, Zuhar Zahir Tuan Harith, Nabila Hannah Samsol Bahri and Noorbaizura Hashim

Minerals 2023, 13(1), 56; https://doi.org/10.3390/min13010056 - 29 Dec 2022

Cited by 4 | Viewed by 1585

Abstract

The evaluation of caprock integrity and reservoir efficiency is critical for safe CO₂ geological storage management. It is therefore important to investigate geochemical reactions between CO₂-rich fluids and host rocks and their contribution in retaining CO₂ at depth. This [...] Read more.

The evaluation of caprock integrity and reservoir efficiency is critical for safe CO₂ geological storage management. It is therefore important to investigate geochemical reactions between CO₂-rich fluids and host rocks and their contribution in retaining CO₂ at depth. This study deals with diffusive reaction experiments on shales and carbonate samples cored from an offshore structure in the Malaysian basin, a potential target for CO₂-enhanced gas recovery. The aim is to evaluate the CO₂ reaction front velocity in a typical shaly caprock and the mineral response of the reservoir. Rock samples were characterized in terms of texture, chemistry, and mineralogy by X-ray diffraction, electron microscopy (SEM), microanalysis (EDS), infrared spectroscopy (FT-IR), rock geochemistry (XRF), and mercury injection capillary permeability (MICP). Performed analyses show mineralogical alteration induced by CO₂ as it penetrated into the samples. Carbonate dissolution and weathering of pyrite to form secondary carbonates belonging to siderite-ankerite series were observed along two reaction fronts. Estimated diffusion coefficients of CO₂ are two orders of magnitude lower than CO_2(aq) molecular diffusion in pure water and from half to an order of magnitude lower than diffusivity computed on unaltered sample, highlighting the important effect of gas–water–rock reactions on the CO_2(aq) diffusivities in shales and carbonates. Results obtained in this study provide an insight regarding the effect of geochemical reactions on CO₂ transport and represent a further discussion point on the diffusion coefficients. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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15 pages, 4978 KiB

Open AccessArticle

Reaction Characteristics of Two Types of Shale with Supercritical CO₂ and Its Potential Impact on Flow-Back Strategies

by Wei Yan, Guangyao Leng, Wenbo Li, Tao Wu, Mustajab Safarov, Jean P. E. Amboulou Ndessabeka and Keyu Meng

Minerals 2022, 12(11), 1459; https://doi.org/10.3390/min12111459 - 18 Nov 2022

Cited by 1 | Viewed by 1670

Abstract

Supercritical carbon dioxide (SC-CO₂) fracturing has been used in developing low permeability and water-sensitive reservoirs in recent years, which is expected to become a new generation of unconventional reservoir fracturing fluid. However, the water-rock interaction characteristics of various lithology shales under [...] Read more.

Supercritical carbon dioxide (SC-CO₂) fracturing has been used in developing low permeability and water-sensitive reservoirs in recent years, which is expected to become a new generation of unconventional reservoir fracturing fluid. However, the water-rock interaction characteristics of various lithology shales under SC-CO₂ circumstance and its influence on fracturing effect still need to be investigated. Two kinds of shale samples from C7 and S1 formations of the Ordos Basin were treated by SC-CO₂ with formation water. The aims of the research are to determine the processes taking place in shale reservoir when considering minerals components transformation, porosity/permeability variation, and micro pore-structure change during the SC-CO₂ fracturing. Static and dynamic SC-CO₂ immersed experiments were conducted and the scanning of electron microscopy (SEM) and X-ray diffraction (XRD) was employed to analyze the surface morphology and newly formed minerals. Helium porosimeter, the ultralow permeability meter, and the CT scanner are employed to record the alternation of physical parameters during SC-CO₂ dynamic injection. The experimental results show that the C7 samples are rich of chlorite and easily reacting with SC-CO₂ saturated formation water to form new minerals, but the S1 samples are insensitive to aqueous SC-CO₂. The minimum value of permeability and porosity of the C7 cores appear at 24h in the long-interval experiment, but in the short-interval dynamic experiment, the minimum values move ahead to 12h. The optimal flowback time for the C7 reservoir is before 12 h or after 24 h. The high-pressure SC-CO₂ flooding pushes the new forming minerals particles to migrate to the outlet side and block the pore throat. For the S1 core results, the porosity and permeability change little in both short and long interval experiments. There is no strict flow-back time requirement for S1 reservoir during SC-CO₂ fracturing. This study is significance for the efficient application of SC-CO₂ in the exploitation of shale oil reservoirs. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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18 pages, 6386 KiB

Open AccessFeature PaperArticle

Effects of Alkanolamine Absorbents in Integrated Absorption–Mineralization

by Chanakarn Thamsiriprideeporn and Suekane Tetsuya

Minerals 2022, 12(11), 1386; https://doi.org/10.3390/min12111386 - 30 Oct 2022

Cited by 1 | Viewed by 1495

Abstract

Integrated absorption–mineralization (IAM) involves the transformation of CO₂ in a chemical-based solution with brine used as the absorbent to form insoluble carbonates and is promising for carbon capture, utilization, and storage. Various types of absorbents such as monoethanolamine (MEA), diethanolamine (DEA), triethanolamine [...] Read more.

Integrated absorption–mineralization (IAM) involves the transformation of CO₂ in a chemical-based solution with brine used as the absorbent to form insoluble carbonates and is promising for carbon capture, utilization, and storage. Various types of absorbents such as monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), and aminomethyl propanol (AMP) were examined in multicycle integrated absorption–mineralization (multicycle IAM) involving absorption, precipitation, and regeneration steps between 20 °C and 25 °C at atmospheric pressure in order to reveal their performance in terms of CO₂ absorption and conversion and absorbent degradation. We found that 5 wt.% AMP offered 89.5% CO₂ absorption capacity per unit of absorbent converted into the amount of solid carbonate within 4 cycles. In addition, it was moderately degraded by 64.02% during the first cycle and then reduced from 30% to 10% in the next cycle (>2 cycles). In comparison with MEA, which was used as the initial absorbent, AMP provided a fivefold increase in the speed of multicycle IAM. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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14 pages, 2014 KiB

Open AccessArticle

The Extraction Effect of Supercritical CO₂ on Coal Organic Matter Based on CO₂ Sequestration in Unmineable Coal Seam

by Renxia Jiang and Hongguan Yu

Minerals 2022, 12(10), 1254; https://doi.org/10.3390/min12101254 - 30 Sep 2022

Cited by 1 | Viewed by 1197

Abstract

On the basis of the effect of extraction components of supercritical CO₂ (Sc-CO₂) from coal on groundwater in the fields of greenhouse gas CO₂ sequestration into deep and unmineable coal seams, Sc-CO₂ extracts from coals were analyzed using [...] Read more.

On the basis of the effect of extraction components of supercritical CO₂ (Sc-CO₂) from coal on groundwater in the fields of greenhouse gas CO₂ sequestration into deep and unmineable coal seams, Sc-CO₂ extracts from coals were analyzed using GC/MS to investigate the compositions and their contents of the extracts under different experimental conditions. The results show that Sc-CO₂ extracts from coals contain hydrocarbons and organic compounds containing heteroatoms. The main compound in the extract is hydrocarbons which include a large concentration of acyclic alkanes and alkenes and a small concentration of cycloalkanes and aromatic hydrocarbons. Even-numbered n-alkane dominates in the extract, and hexacosene is the main alkene in the extracts from lignite and bituminous coal. The aromatic hydrocarbons are more difficult to extract and their concentration decreases with the increase of coal rank. The main oxygen-containing compounds are esters and carboxylic acids which are more easily extracted from lignite. The concentrations of nitrogen-containing compounds are very small and are more difficult to extract from coal with the rank increase. A small concentration of sulfur-containing compounds is extracted from coal. The results demonstrate that Sc-CO₂ has the potential to mobilize organic compounds from coal seams, which affect the transport of CO₂ in coal seams and cause groundwater pollution. Full article

(This article belongs to the Special Issue CO₂ Geological Storage: Fluid–Rock Interactions and Geochemical Modeling)

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