A novel method for extracting information on pores from cast thin-section images

Dong, Shaoqun; Zeng, Lianbo; Xu, Chaoshui; Dowd, P. A.; Gao, Zhiyong; Mao, Zhe; Ai, Wang

doi:10.1016/j.cageo.2019.05.003

Cited by 31 publications

(15 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because ordinary thin slices are not easy to identify microcracks and other structures, in order to find these structures clearly and intuitively, the granite samples were impregnated with epoxy resin in a vacuum box; and these epoxy resins are added with blue dye to make them more eye-catching. In this way, the pore and crack structure could be analyzed very clearly and intuitively, and the porosity and other characteristics of the rock could be evaluated [36,37].…”

Section: Optical Microscopementioning

confidence: 99%

The Size Effect and Microstructure Changes of Granite after Heat Treatment

Zhang

Song

et al. 2021

Advances in Materials Science and Engineering

View full text Add to dashboard Cite

High temperature can change the mechanical properties of granite, with significant nonlinear characteristics, and at the same time change its microstructure. Therefore, two kinds of granites are used in this paper: one is normal temperature granite and the other is granite treated at 600°C, and a detailed comparative study is made. The fracture toughness of two kinds of rocks was tested by fracture tests, and the results were analyzed by a nonlinear fracture mechanics model (SEL). At the same time, in order to understand the influence of high temperature on the mineral composition and microstructure of granite, XRD, optical microscope, and SEM were used to observe the mineral composition, microcracks, and fracture morphology of granite. The results show the following: (1) high temperature significantly changes the fracture mechanics parameters of granite. The fracture toughness of granite treated at 600°C is significantly lower than that of untreated granite, which is reduced by more than 60%. (2) No obvious size effect was found in the untreated granite, while the size effect of the granite after treatment at 600°C was significant. (3) The granite after high-temperature treatment showed strong nonlinear characteristics, and the SEL can reasonably describe and explain its nonlinear fracture characteristics. (4) The brittleness of the granite treated at 600°C decreased and the ductility increased. The microscopic morphology of the fracture was rough, with obvious steps and rivers. The microcracks and porosity had increased significantly, but the main components did not change significantly.

show abstract

Section: Optical Microscopementioning

confidence: 99%

The Size Effect and Microstructure Changes of Granite after Heat Treatment

Zhang

Song

et al. 2021

Advances in Materials Science and Engineering

View full text Add to dashboard Cite

show abstract

“…As the thin slices cannot easily distinguish the pore structure in the rock, the sandstone was impregnated with epoxy resin added with blue dye, in order to visually compare the size of the pores and cracks in the sandstone before and after heating. In this way, the blue resin highlighted the pores and cracks, and it was possible to analyze the pores and crack structures intuitively and clearly, as well as to estimate the porosity and other characteristics of the sandstone [32][33][34].…”

Section: Optical Microscopementioning

confidence: 99%

Effect of High Temperature (600°C) on Mechanical Properties, Mineral Composition, and Microfracture Characteristics of Sandstone

Zhang

2020

Advances in Materials Science and Engineering

View full text Add to dashboard Cite

Rock destruction under high-temperature conditions is a key issue for nuclear waste treatment projects, underground coal gasification, and improvement of the use of geothermal energy for heating. Therefore, in this study, various methods and techniques were integrated to study the changes in mechanical properties, mineral composition, and microscopic fracture characteristics of Sichuan sandstone treated at 600°C. First, the fracture toughness and indirect tensile strength of untreated sandstones and high-temperature treated sandstones were tested by the MTS testing machine, and the double-K model (DKFM) was used to estimate the unstable fracture toughness. Then, the diffraction spectra of sandstone were analyzed with an X-ray diffractometer to determine the mineral composition change after heat treatment. Finally, the microscopic features of sandstone were observed through a scanning electron microscope (SEM) and optical microscope. The results show the following. (1) There is no significant change in the tensile strength and fracture toughness of Sichuan sandstone treated at 600°C. (2) The brittleness of Sichuan sandstone decreases and the ductility increases after high-temperature treatment. (3) The unstable fracture toughness value Kun obtained by the double-K model (DKFM) is significantly larger than the apparent fracture toughness value Kif. (4) After treatment at 600°C, the clay minerals in the sandstone changed significantly. Kaolinite is dehydroxylated to metakaolinite, which may increase the ductility of the rock.

show abstract

“…The cast thin section (CTS) is a rock flake, prepared by injecting and subsequently solidifying colored liquid glue into the pore spaces of the rock sample under vacuum pressure [31,32]. Interpretation of cast thin sections is one of the conventional methods to analyze rock minerals and oil-gas reservoirs.…”

Section: Microscopic Observation Methodmentioning

confidence: 99%

Filling Provenance in Fracture Cavity Formation within Aksu Area, Tarim Basin, NW China: Indicators from Major and Trace Element, Carbon-Oxygen, and Strontium Isotope Compositions

Ren

et al. 2021

Lithosphere

View full text Add to dashboard Cite

With an aim to increase the understanding about sedimentary environment and isotopic and chemical characteristics of fillings in fracture cavities with multiple compositions, we conducted scanning electron microscope (SEM), fluid inclusion testing (FIT), common and trace element chemistry, full analysis testing, isotopic compositions (δ13C, δ18O, 87Sr/86Sr), and apatite fission track testing to study the formation environment of Aksu area, Tarim Basin. According to outfield and microscope observations, combined with SEM results, three textural and compositional type fractures and cavities were distinguished. Through fine analysis of geochemistry characteristics on fractures, cavities, multiple filling periods, and environments were interpreted. Constrained by rare earth element (REE) pattern diagram, relationships between carbon and oxygen isotopes, strontium isotope, the compositional patterns, and generation environment of the fracture and cavities were determined. The results show that (1) cavity, fracture filling, and wall rock primarily consist of calcite, with a proportion of 56.85%, 80.48%, and 81.00%, respectively. (2) Four fracture sets have been distinguished in the Ordovician limestone of the karst cave, Middle-Late Caledonian (Set 1), Early Hercynian (Set 2), Indo-Yanshanian (Set 3), and Himalayan orogeny (Set 4). Two stages of cave filling deposition are distinguished. Stage I was coeval with the Middle-Late Caledonian Set 1 fractures and is attributable to the circulation of freshwater fluid. Stage II was coeval with the Early Hercynian Set 2 fractures and is attributable to deep hydrothermal fluid circulation. (3) Cavity, fracture filling, and wall rock in Ordovician strata are slightly influenced by diagenesis alteration and territorial supply. Three significant filling stages were distinguished, freshwater fluid with strong oxidizing environment (Middle-Late Caledonian), hydrothermal fluid with authigenic abnormal enrichment (indicating obvious hypoxic sedimentary water, Early Hercynian), and high-temperature hydrothermal fluid from deep earth (primarily influenced by magmatism, Indo-Yanshanian, and Himalayan).

show abstract

A novel method for extracting information on pores from cast thin-section images

Cited by 31 publications

References 32 publications

The Size Effect and Microstructure Changes of Granite after Heat Treatment

The Size Effect and Microstructure Changes of Granite after Heat Treatment

Effect of High Temperature (600°C) on Mechanical Properties, Mineral Composition, and Microfracture Characteristics of Sandstone

Filling Provenance in Fracture Cavity Formation within Aksu Area, Tarim Basin, NW China: Indicators from Major and Trace Element, Carbon-Oxygen, and Strontium Isotope Compositions

Contact Info

Product

Resources

About