CO2-water-shale interaction induced shale microstructural alteration

Zhou, Junping; Yang, Kailun; Tian, Shifeng; Zhou, Lei; Xian, Xuefu; Liu, Muhan; Cai, Jianchao

doi:10.1016/j.fuel.2019.116642

Cited by 91 publications

(60 citation statements)

References 79 publications

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“…When shale rocks are exposed to CO 2 -water mixtures, chemical reactions such as the dissolution of calcite, carbonates and clay minerals could be observed. 304 If the imbibition time is long, quartz could also be dissolved. 305 The geochemical reactions can potentially affect petrophysical properties which will be discussed below.…”

Section: Co 2 -Shale or Co 2 -Liquid-shale Interactionsmentioning

confidence: 99%

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

Lyu

Tan

et al. 2021

Energy Environ. Sci.

124

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Section: Co 2 -Shale or Co 2 -Liquid-shale Interactionsmentioning

confidence: 99%

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

Lyu

Tan

et al. 2021

Energy Environ. Sci.

124

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“…At present, several test methods are used to analyze the interaction between supercritical CO 2 and the shale microstructure, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and low-pressure nitrogen gas adsorption (N 2 GA). 40 − 43 Some studies have shown that supercritical CO 2 can extract water molecules from minerals to form carbonic acid and dissolve carbonate minerals. 44 Lyu et al 45 , 46 found that new pores appeared on the surfaces of shale slices after being saturated with sub-/super-critical CO 2 , and an increase in carbon content confirmed a chemical reaction between CO 2 and shale.…”

Section: Introductionmentioning

confidence: 99%

Different Effect Mechanisms of Supercritical CO₂ on the Shale Microscopic Structure

Zhou

et al. 2020

ACS Omega

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To better understand how supercritical carbon dioxide (CO 2 ) enhances shale gas production, it is necessary to study the interaction of supercritical CO 2 with shale and its impact on shale microstructure. The different mechanisms by which supercritical CO 2 changes the shale pore structure were studied by X-ray diffraction analyses, scanning electron microscopy (SEM), nuclear magnetic resonance spectroscopy, and low-pressure nitrogen gas adsorption tests on shale samples before and after treatment with different pressures and gases (CO 2 and Ar). The results showed that after treatment with CO 2 , the mineral content of shale changed significantly, and in particular, the proportions of calcite and dolomite decreased. The mineral content of shale changed the most after treatment with supercritical CO 2 , and the microscopic pores were most observable by SEM. In a gaseous CO 2 environment, the effect of CO 2 adsorption on shale pores is greater than the effects of gas pressure and dissolution reactions. However, in a supercritical CO 2 environment, the changes in shale pore structures are mainly controlled by extraction and dissolution reactions. When shale is exposed to supercritical CO 2 , the fractal dimensions of adsorption pores and seepage pores decrease, indicating that the specific surface area and roughness of adsorption pores decrease. This implies that the adsorption capacity decreases, and that the complexity of the seepage pores declines, which is conducive for gas migration.

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“…Jiang et al (2016) found that supercritical carbon dioxide (SC-CO 2 ) extracted organic matter from shale and dissolved the original pores and cracks by examining the reaction between shale and CO 2 at different times, temperatures, and pressures. Ao et al (2017) and Zhou et al (2020) speculated on a potential reaction between shale and CO 2 using X-ray diffraction (XRD) analysis of mineral component changes before and after the reaction. Pan et al (2018) and Yin et al (2016) used FTIR to identify and discuss the characteristic peaks of the functional groups after shale reacted with CO 2 ; they found that CO 2 shale caused some functional group content changes, but did not reduce the functional group types.…”

Section: Introductionmentioning

confidence: 99%

“…Ao et al. (2017) and Zhou et al. (2020) speculated on a potential reaction between shale and CO 2 using X-ray diffraction (XRD) analysis of mineral component changes before and after the reaction.…”

Section: Introductionmentioning

confidence: 99%

Chemical structure changes of marine shale caused by supercritical carbon dioxide

Tang

et al. 2020

Energy Exploration & Exploitation

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The interaction between shale and CO2 is of great significance to CO2 storage and shale gas production; however, there are few reports on chemical changes after CO2 injection into shale reservoirs. We used Fourier transform infrared spectroscopy to study the chemical structure changes of shale samples before and after CO2 injection. In this paper, self-developed high-temperature and high-pressure vessels were used to examine CO2 treatment of shale to simulate the stratigraphic environment and infrared was used to study the influence of changes in pressure and temperature on the chemical interaction between shale and CO2. These results showed that: (1) after shale CO2 treatment, the number of functional groups remained unchanged, though the content and structure of the shale did change; (2) pressure increases reduced hydroxyl and aliphatic group levels in the shale; the branched-chain and aromaticity indexes of the shale were reduced by 81.5% and 53.8%, respectively, relative to untreated samples; (3) below 60°C, free water in the shale increased with temperature increases and dissolution of the shale increased; however, above 60°C, dissolution was inhibited which resulted in precipitation; (4) the dissolution degree of shale carbonate minerals positively correlated with CO2 pressure and temperature, while silicate minerals were unchanged CO2 pressure and temperature. Finally, the change of CO2 pressure had a more significant influence on the chemical structure of shale. These results provide a basis for the continuing study of the influence of chemical structure change of shale caused by CO2 on shale wettability and enhance the theoretical level of CO2 shale mining.

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CO2-water-shale interaction induced shale microstructural alteration

Cited by 91 publications

References 79 publications

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

Different Effect Mechanisms of Supercritical CO₂ on the Shale Microscopic Structure

Chemical structure changes of marine shale caused by supercritical carbon dioxide

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CO2-water-shale interaction induced shale microstructural alteration

Cited by 91 publications

References 79 publications

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

The role of supercritical carbon dioxide for recovery of shale gas and sequestration in gas shale reservoirs

Different Effect Mechanisms of Supercritical CO2 on the Shale Microscopic Structure

Chemical structure changes of marine shale caused by supercritical carbon dioxide

Contact Info

Product

Resources

About

Different Effect Mechanisms of Supercritical CO₂ on the Shale Microscopic Structure