Similar Material Proportioning and Preparation of Ductile Surrounding Rocks for Simulating In Situ Coalbed methane Production from Tectonically Deformed Coals

Hou, Xin; Zhou, Xiaozhi; Pan, Jienan

doi:10.1007/s00603-022-02951-3

Cited by 6 publications

(6 citation statements)

References 41 publications

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“…Because specimens made directly from raw coal are often poorly homogeneous and difficult to obtain, laboratories typically use coal-like specimens instead of raw coal for testing. The two common types of coal-like materials are briquettes, which are formed by mixing pulverized coal and water and pressing with special molds, − and material specimens made by the ratio of similar materials such as cement, sand, and gypsum. − Researchers have done a lot of work on the differences of physical parameters and failure mechanisms between briquettes and raw coal. Wang et al compared briquettes made of pulverized coal with those made of primary tectonic coal and found that the bonds generated in the briquette were more likely to be broken than the original bonds in the raw coal, and the hardness of the briquettes was significantly lower than that of the primary tectonic coal.…”

Section: Introductionmentioning

confidence: 99%

Resistivity Response Characteristics of Coal and Coal-like Materials under Uniaxial Compression

Hu,

Liu,

et al. 2024

Energy Fuels

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Resistivity is the core electrical parameter of coalfield electrical prospecting technology to identify geological anomaly areas. Studying the change characteristics of the resistivity of coal under loading is helpful to further improve the accuracy of electric prospecting in delineating the abrupt change area of coal structure and to enhance the ability to reduce and avoid disasters in coal mine production processes. In this study, the resistivity of raw coal and coal-like specimens was monitored under uniaxial compression. The influence mechanism of the coupling structure and moisture on the resistivity of raw coal and coal-like specimens was analyzed. Additionally, the change law of the electrical characteristics during the instability process and the corresponding relationship between the resistivity change and the mechanical behavior of specimens were characterized. The results show that the uniaxial compressive strength and elastic modulus of raw coal specimens are close to the similar-material specimens but much larger than the coal briquette specimens, and the effect of water on similar-material specimens is greater than the coal briquette specimens. The curve of resistivity change over time can be divided into four stages according to the change process of the stress−strain curve. The resistivity of the specimens in stages I and II exhibited a decreasing trend, except for the specimens of similar materials under natural conditions. The trends of the different types of specimens in Stage III were different, and the specimens in Stage IV showed an increasing trend. The order of the resistivity change rate at the stress peak compared to the initial point was as follows: natural similar-material specimen > water-soaked briquette > raw coal > natural briquette > water-soaked similar-material specimen. The experimental results provided theoretical support for further understanding the differences between coal-like materials and raw coal.

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Section: Introductionmentioning

confidence: 99%

Resistivity Response Characteristics of Coal and Coal-like Materials under Uniaxial Compression

Hu,

Liu,

et al. 2024

Energy Fuels

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“…Wang 20 used river sand as the skeleton of similar materials and used additives such as nano-calcium carbonate, calcium bentonite, Plaster, and emulsified wax to create new similar materials that can simulate formation separation. Hou 21 used the comprehensive balance method to study similar materials using sand-to-gel ratio, Plaster-talcum powder ratio, water-to-solid ratio, molding pressure, and molding time without affecting factors, providing a certain reference for similar experiments. Cui 22 synthesized red mudstone material by means of mineral composition and ratio completely similar to natural rock samples and compared the physical and mechanical properties of synthetic red mudstone material and natural red mudstone.…”

Section: Introductionmentioning

confidence: 99%

Research on the ratio of similar materials in water-absorbent mudstone based on fuzzy mathematics

Zeng,

Zhou,

Xiaoding

2024

Sci Rep

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To determine the suitability and credibility of similar water-absorbent mudstone materials in model experiments, the prototype mudstone parameter similarity index was determined based on the similarity theory. Similar materials use cement and Plaster as binders and quartz sand as aggregate. The sensitivity of similar indicators of similar materials to control factors was analyzed through range statistics. Multiple regression analysis was used to establish the quantitative relationship between each control factor and similar indicators. Finally, the optimal matching scheme was refined through the combination of fuzzy mathematics and analytic hierarchy process. The results show that the physical and mechanical property indicators of similar materials with different proportions have a wide distribution range, and under certain similar conditions, they can meet the requirements of rock model tests with different properties. The aggregate-binder ratio is a direct indicator of material density, elastic modulus, and compressive strength. The main controlling factors, material density, elastic modulus, and compressive strength all increase with the decrease in aggregate-binder ratio. The cement-plaster ratio is the main control factor of material water absorption, and the water absorption gradually decreases with the increase of the cement-plaster ratio. The formula obtained through linear analysis can better represent the changing trend and distribution characteristics of various parameters of similar materials with the aggregate-binder ratio and cement-plaster ratio, and initially optimize the proportioning scheme of similar materials. Use fuzzy mathematics to evaluate the membership degree of each parameter index of similar materials, and the optimal ratio scheme was further determined to improve the credibility of later model experiments.

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“…3,4 In recent years, coalbed methane geologists and coal mining engineers have increasingly focused on understanding the impacts of tectonic deformation on the physical properties of coal, leading to a substantial body of research. 4,7 However, given the intricate nature of coal pore systems, additional investigations are required.…”

Section: Introductionmentioning

confidence: 99%

Effect of Tectonic Deformation on the Pore System and Methane Adsorption of Anthracite Coal

Zhu,

Jing,

Yuan

et al. 2024

ACS Omega

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Tectonic deformation significantly alters the physical structure of coals, holding great importance to the coal mining industry and coalbed methane. In this study, eight anthracite coal samples with varying degrees of deformation were collected to investigate the effects of tectonic deformation on the pore system and CH 4 adsorption of anthracite coals. In addition, lowtemperature gas adsorption (N 2 and CO 2 ), Raman spectroscopy, and CH 4 isothermal experiments were performed. The results revealed that coal samples with higher degrees of deformation exhibited larger ratios of D-band intensity to G-band intensity (I D /I G ), indicating increased molecular defects induced by tectonic deformation. As the deformation degree of the coal samples increased, the mesopore volume increased from 0.00044 cm 3 /g (primary coal) to 0.0019 cm 3 /g (scaly coal). Conversely, the micropore volume tended to decrease with the increasing deformation degree of the coal samples. Moreover, the impact of deformation degree on the CH 4 adsorption capacity of anthracite coals was complex. With the deformation degree increasing, the Langmuir volume initially decreased from 32.0 to 24.55 cm 3 /g and then rose to 30.14 cm 3 /g. This complexity arose from the differential effects of tectonic deformation on various pore types, where micropores and mesopores collectively determined the CH 4 adsorption capacity of anthracite coals. This study analyzed the influence of tectonic deformation on the pore structure and CH 4 adsorption capacity at the molecular level, providing valuable insights for evaluating the in situ CH 4 content in anthracite coal seams.

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Similar Material Proportioning and Preparation of Ductile Surrounding Rocks for Simulating In Situ Coalbed methane Production from Tectonically Deformed Coals

Cited by 6 publications

References 41 publications

Resistivity Response Characteristics of Coal and Coal-like Materials under Uniaxial Compression

Resistivity Response Characteristics of Coal and Coal-like Materials under Uniaxial Compression

Research on the ratio of similar materials in water-absorbent mudstone based on fuzzy mathematics

Effect of Tectonic Deformation on the Pore System and Methane Adsorption of Anthracite Coal

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