Article
Energy & Fuels
Hossein Fazeli, Veerle Vandeginste, Arash Rabbani, Masoud Babaei, Bagus Muljadi
Summary: This study investigates the impact of the pore-scale distribution of calcite on the structural alteration of shales using a pore-scale reactive transport model. The results indicate that calcite dissolution leads to permeability enhancement, with a more pronounced effect on shales with coarser calcite grains. Higher calcite content can result in higher pH values, higher permeabilities, and more barite precipitation in the domain, as shown by simulations.
Article
Engineering, Geological
M. Zhang, C. J. Spiers, S. J. T. Hangx
Summary: CO2 uptake by smectites can cause swelling and self-stressing in shallow clay-rich caprocks under CO2 storage P-T and constrained conditions. However, little data exist to constrain the magnitude of the effects of CO2-H2O-smectite interactions on the sealing properties of clay-rich caprocks and faults. Our experiments on Opalinus Claystone (OPA) cores and simulated fault gouge showed that the permeability of clayey caprock can decrease significantly when exposed to CO2-rich fluid, depending on the initial water activity in the clay material. These findings have important implications for assessing the self-sealing potential of fractured and faulted clay-rich caprocks.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Ning Li, Zhijun Jin, Haibo Wang, Yushi Zou, Shicheng Zhang, Fengxia Li, Tong Zhou, Minqu Jiang
Summary: In this study, the shale softening behavior induced by water/CO2-rock interaction was investigated using SEM observation and nanoindentation tests. It was found that the extent of micromechanical degradation was influenced by the soaking fluid type and time. SEM images showed that fractures induced by hydration had larger apertures compared to those induced by adsorption. The statistical results of nanoindentation tests demonstrated that the Young's modulus and hardness decreased significantly with increased soaking time for water soaking, while the extent of shale softening was alleviated for CO2 soaking.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Energy & Fuels
Ahmed Al-Yaseri, Abduljamiu Amao, Ahmed Fatah
Summary: Underground Hydrogen Storage (UHS) is an effective technique for long-term energy storage, but the reactions between hydrogen and shale formations can impact the seal integrity. This study investigates the geochemical reactions between hydrogen and calcite-rich shale samples and finds that calcite precipitation occurs due to the presence of organic contents. However, no significant changes in the pore structure or hydrogen loss were observed. The results suggest that shale-caprocks can maintain their integrity during hydrogen injection and production, making them suitable for UHS.
Article
Thermodynamics
Kang Yang, Junping Zhou, Xuefu Xian, Lei Zhou, Chengpeng Zhang, Shifeng Tian, Zhaohui Lu, Fengshou Zhang
Summary: This study investigates the impact of ScCO2-water exposure on shale properties and reveals the changes in mineral composition, pore structure, and mechanical properties due to the chemical-mechanical interaction. The results indicate that the interaction leads to changes in shale porosity and permeability, with chemical reactions increasing the porosity in unstressed conditions and the chemical-mechanical coupling effects decreasing the permeability in stressed conditions. The findings highlight the importance of understanding the chemical-mechanical processes in shale for optimizing gas recovery and CO2 sequestration.
Article
Geochemistry & Geophysics
Qi Zhang, Jiehao Wang, Yufeng Gao, Shengfei Cao, Jingli Xie, Like Ma, Yuemiao Liu
Summary: The study uses a damage evolution law to simulate the behavior of hydraulic fractures crossing different preexisting fractures, finding that the bedding plane angle and stress ratio significantly influence the propagation direction of fractures.
Article
Energy & Fuels
Ran Lin, Zhihao Yu, Jinzhou Zhao, Caili Dai, Yongpeng Sun, Lan Ren, Mengke Xie
Summary: This study investigates the impact of CO2 flooding on tight sandstones, revealing that the corrosion process enhances porosity and liquid permeability while reducing the pore and throat diameter for movable fluids. XRD analysis indicated main corrosion minerals to be calcite, dolomite, and feldspar, with significantly increased corrosion pores post-reaction. These findings suggest improved formation petrophysical properties associated with CO2 flooding in tight sandstones, providing a theoretical basis for the efficient development of tight oil reservoirs.
Article
Thermodynamics
Yuhao Hu, Guannan Liu, Ning Luo, Feng Gao, Fengtian Yue, Tao Gao
Summary: This study establishes a structural analysis model for shale gas based on fractal geometry theory and multi-scale models. The results demonstrate the significant impact of effective stress, local mechanical property changes, and adsorption effects on shale gas production rate.
Article
Thermodynamics
Sihai Li, Shicheng Zhang, Huilin Xing, Yushi Zou
Summary: The introduction of CO2 in deep formations has complex effects on geochemical/geophysical processes, CO2 geological storage, and oil/gas recovery. Previous studies have focused on long-term geochemical reactions in low carbonate content reservoirs, neglecting the short-term CO2-brine-rock interaction in carbonate-rich formations. This study quantifies the properties of carbonate-rich shale reservoirs after CO2 fracturing and reveals the alteration mechanisms through soaking experiments and multi-scale tests.
Article
Geosciences, Multidisciplinary
Anbin Wu, Jian Cao, Jingkun Zhang
Summary: The study shows that bedding-parallel calcite veins in shale have two stages of growth, with early veins formed in low-temperature, high-salinity diagenetic fluids and late veins formed in high-temperature, low-salinity diagenetic fluids, reflecting the evolution of organic matter in the oil and gas generation process.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Energy & Fuels
Jin-Hong Chen, Stacey M. Althaus, Hui-Hai Liu, Jilin Zhang, Gary Eppler, Jewel C. Duncan, Qiushi Sun
Summary: This study provides experimental evidence that electromagnetic thermal stimulation can significantly increase the permeability of source rock shales, showing that this method is efficient in production especially in regions with limited water resources. Microwave heating was found to generate extensive fractures in the samples, resulting in a significant increase in permeability.
Article
Chemistry, Multidisciplinary
Chunyan Bao, Meng Zhou, Yuexiang Cai
Summary: This study investigates the effect of low-temperature fracturing with liquid nitrogen on shale crack propagation through experiments and simulations. It is found that different crack development modes occur depending on the degree of homogeneity. The study also analyzes the influence of parameters such as heat transfer coefficient and in situ stress on shale temperature, stress distribution, and crack propagation.
APPLIED SCIENCES-BASEL
(2022)
Article
Energy & Fuels
J. Alexandra Hakala, Amelia N. Paukert Vankeuren, Peter P. Scheuermann, Christina Lopano, George D. Guthrie
Summary: This study used laboratory experiments and reaction path modeling to identify mineral precipitation reactions in hydraulically fractured shale, demonstrating their potential impact on reservoir performance. The agreement between geochemical models and experimental results suggests that numerical models can effectively screen potential fluid-mineral reactions in unconventional reservoirs.
Article
Construction & Building Technology
Qian Li, Jing Li, Baolong Zhu
Summary: The study investigates the mineral alteration and porosity evolution of shale during deterioration processes caused by water-rock reactions. Sequential water-rock reactions accelerate the mineral alterations and porosity changes, with greater effects observed in the latter part of the sequence. The findings suggest that the self-designed reaction system effectively represents sequential water-rock reactions and the deterioration of shale increases successively along the water flow direction.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Energy & Fuels
Ahmed Al-Yaseri, Israa S. Abu-Mahfouz, Nurudeen Yekeen, Domenik Wolff-Boenisch
Summary: There is increasing global interest in achieving a carbon dioxide-free global economy by replacing carbon-based fossil fuels with clean hydrogen. However, the low volumetric energy content of hydrogen requires large-scale storage to address the energy demand and supply imbalance. Underground Hydrogen Storage (UHS) is an appealing technology for global decarbonization, and the Jordan oil shale has been proposed as a promising storage medium. This study investigates the reaction between hydrogen and organic-rich shale, as well as the potential methane production.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Environmental Sciences
Shugang Yang, Qingchun Yu
WATER RESOURCES RESEARCH
(2020)
Article
Energy & Fuels
Shugang Yang, Xingchun Li, Kunfeng Zhang, Qingchun Yu, Xianyuan Du
Summary: The pore structure and mineral composition have a significant impact on the water flow behavior in low-permeability media. Both clay minerals and brittle minerals affect the pre-Darcy flow parameters in opposite ways. Experimental and theoretical analysis reveal that immovable water and electro-viscous effect play a key role in deviating water flow from Darcy's law.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)