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Toshihiko Shimamoto - One of the best experts on this subject based on the ideXlab platform.
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Graphite as a Lubricating Agent in fault zones: An insight from low‐ to high‐velocity friction experiments on a mixed graphite‐quartz gouge
Journal of Geophysical Research, 2013Co-Authors: Kiyokazu Oohashi, Takehiro Hirose, Toshihiko ShimamotoAbstract:[1] Graphite is a very low friction material, often enriched within fault zones due to mechanical or chemical processes. The effects of weak minerals on the strength of faults have been examined by friction experiments on bimineralic mixtures. However, previous experiments were conducted with limited shear strains, even though applied shear strains and textural developments had already been signaled as significant factors in the weakening of faults. We therefore conducted large-displacement, low- to high-velocity friction experiments with graphite-quartz gouges, to determine how much graphite is needed to reduce frictional strength, and to examine how textures contribute to the strength reduction of a mature fault at various slip rates. We found that the coefficients of friction of the gouges decrease nonlinearly with increasing graphite fraction for any given shear strain and slip rate, decreasing first with 5–20 vol% graphite, then reaching similar frictional levels to pure graphite with 30–50 vol% graphite. The nonlinear weakening trends can be fitted by sigmoidal curves. The weakening with 10–30 vol% graphite is associated with zones of slip-localization and the development of a graphite-lubricated penetrative slip surface(s). With increasing shear strain, the relationship between strength and graphite fraction evolves abruptly from an early gentle curve to a sigmoidal curve, and the frictional strength drops significantly even with small amounts of graphite (~10 vol%). Our results highlight the importance of shear strain and textural developments on weak faults, not only with respect to graphite, but also other fault lubricants such as the phyllosilicates.
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graphite as a Lubricating Agent in fault zones an insight from low to high velocity friction experiments on a mixed graphite quartz gouge
Journal of Geophysical Research, 2013Co-Authors: Kiyokazu Oohashi, Takehiro Hirose, Toshihiko ShimamotoAbstract:[1] Graphite is a very low friction material, often enriched within fault zones due to mechanical or chemical processes. The effects of weak minerals on the strength of faults have been examined by friction experiments on bimineralic mixtures. However, previous experiments were conducted with limited shear strains, even though applied shear strains and textural developments had already been signaled as significant factors in the weakening of faults. We therefore conducted large-displacement, low- to high-velocity friction experiments with graphite-quartz gouges, to determine how much graphite is needed to reduce frictional strength, and to examine how textures contribute to the strength reduction of a mature fault at various slip rates. We found that the coefficients of friction of the gouges decrease nonlinearly with increasing graphite fraction for any given shear strain and slip rate, decreasing first with 5–20 vol% graphite, then reaching similar frictional levels to pure graphite with 30–50 vol% graphite. The nonlinear weakening trends can be fitted by sigmoidal curves. The weakening with 10–30 vol% graphite is associated with zones of slip-localization and the development of a graphite-lubricated penetrative slip surface(s). With increasing shear strain, the relationship between strength and graphite fraction evolves abruptly from an early gentle curve to a sigmoidal curve, and the frictional strength drops significantly even with small amounts of graphite (~10 vol%). Our results highlight the importance of shear strain and textural developments on weak faults, not only with respect to graphite, but also other fault lubricants such as the phyllosilicates.
Kiyokazu Oohashi - One of the best experts on this subject based on the ideXlab platform.
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Graphite as a Lubricating Agent in fault zones: An insight from low‐ to high‐velocity friction experiments on a mixed graphite‐quartz gouge
Journal of Geophysical Research, 2013Co-Authors: Kiyokazu Oohashi, Takehiro Hirose, Toshihiko ShimamotoAbstract:[1] Graphite is a very low friction material, often enriched within fault zones due to mechanical or chemical processes. The effects of weak minerals on the strength of faults have been examined by friction experiments on bimineralic mixtures. However, previous experiments were conducted with limited shear strains, even though applied shear strains and textural developments had already been signaled as significant factors in the weakening of faults. We therefore conducted large-displacement, low- to high-velocity friction experiments with graphite-quartz gouges, to determine how much graphite is needed to reduce frictional strength, and to examine how textures contribute to the strength reduction of a mature fault at various slip rates. We found that the coefficients of friction of the gouges decrease nonlinearly with increasing graphite fraction for any given shear strain and slip rate, decreasing first with 5–20 vol% graphite, then reaching similar frictional levels to pure graphite with 30–50 vol% graphite. The nonlinear weakening trends can be fitted by sigmoidal curves. The weakening with 10–30 vol% graphite is associated with zones of slip-localization and the development of a graphite-lubricated penetrative slip surface(s). With increasing shear strain, the relationship between strength and graphite fraction evolves abruptly from an early gentle curve to a sigmoidal curve, and the frictional strength drops significantly even with small amounts of graphite (~10 vol%). Our results highlight the importance of shear strain and textural developments on weak faults, not only with respect to graphite, but also other fault lubricants such as the phyllosilicates.
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graphite as a Lubricating Agent in fault zones an insight from low to high velocity friction experiments on a mixed graphite quartz gouge
Journal of Geophysical Research, 2013Co-Authors: Kiyokazu Oohashi, Takehiro Hirose, Toshihiko ShimamotoAbstract:[1] Graphite is a very low friction material, often enriched within fault zones due to mechanical or chemical processes. The effects of weak minerals on the strength of faults have been examined by friction experiments on bimineralic mixtures. However, previous experiments were conducted with limited shear strains, even though applied shear strains and textural developments had already been signaled as significant factors in the weakening of faults. We therefore conducted large-displacement, low- to high-velocity friction experiments with graphite-quartz gouges, to determine how much graphite is needed to reduce frictional strength, and to examine how textures contribute to the strength reduction of a mature fault at various slip rates. We found that the coefficients of friction of the gouges decrease nonlinearly with increasing graphite fraction for any given shear strain and slip rate, decreasing first with 5–20 vol% graphite, then reaching similar frictional levels to pure graphite with 30–50 vol% graphite. The nonlinear weakening trends can be fitted by sigmoidal curves. The weakening with 10–30 vol% graphite is associated with zones of slip-localization and the development of a graphite-lubricated penetrative slip surface(s). With increasing shear strain, the relationship between strength and graphite fraction evolves abruptly from an early gentle curve to a sigmoidal curve, and the frictional strength drops significantly even with small amounts of graphite (~10 vol%). Our results highlight the importance of shear strain and textural developments on weak faults, not only with respect to graphite, but also other fault lubricants such as the phyllosilicates.
Nur Suriani Mamat - One of the best experts on this subject based on the ideXlab platform.
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The performance of polymer beads in water-based mud and its application in high-temperature well
Journal of Petroleum Exploration and Production Technology, 2013Co-Authors: Nur Suriani Mamat, Issham Ismail, Azmi Kamis, Shahrir Hashim, Aizal Haziq Abdul RazakAbstract:The major concern in multilateral drilling is the torque and drag that arises as we drill deeper coupled with the escalation of bottomhole temperature, which can be overcome through the use of a lubricant: a solid or liquid form. Solid lubricants have been proved to be able to reduce the coefficient of friction substantially. In this research work, polymer beads were used as a Lubricating Agent in a high-temperature condition. The polymer beads which possessed improved physical properties were constructed using polymerization of styrene monomer added with divinylbenzene. The molecular structure and thermal properties of the polymer beads were evaluated using Fourier transform infrared analysis (FTIR) and thermogravimetric analysis (TGA), respectively. The lubricity test was conducted on four different types of sample, namely oil-based mud, water-based mud, and water-based mud with polymer and glass beads, at temperatures ranging from 60 to 180 °C. The experimental results were found to give an average reduction of 27.5 % of coefficient of friction at elevated temperature and the rheological properties experienced slight changes above 100 °C as compared to water-based mud. In a nutshell, the polymer beads show the potential to be used as a Lubricating Agent in high-temperature conditions.
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Reducing Friction During Drilling In Water–Based Mud Using Glass Beads
Jurnal Teknologi, 2011Co-Authors: Issham Ismail, Azmi Kamis, Nur Suriani MamatAbstract:Artikel ini mengetengahkan perbincangan tentang penggunaan butiran kaca sebagai agen pelincir berikutan sifatnya yang lengai, tidak menghakis, dan bebas toksik. Saiz butiran kaca yang digunakan adalah dalam julat 22 hingga 163 μm. Hasil kajian menunjukkan bahawa lumpur dasar air yang mengandungi butiran kaca berjaya mengurangkan pekali geseran sebanyak 41% berbanding lumpur dasar air tanpa butiran kaca. Penggunaan 4 ppb butiran kaca dalam lumpur dasar air didapati telah menghasilkan sifat–sifat reologi yang optimum dan kehilangan bendalir yang paling rendah jika dibandingkan dengan lumpur tanpa butiran kaca dan lumpur dengan 2 ppb dan 6 ppb butiran kaca. Keputusan uji kaji juga menunjukkan bahawa karbolit mempunyai potensi untuk digunakan sebagai agen pelincir dalam lumpur dasar air. Kata kunci: pekali geseran; karbolit; butiran kaca; agen pelincir; lumpur dasar air This paper discusses the use of glass beads as a Lubricating Agent, which was considered as it is chemically inert, non–abrasive, and non–toxic. The glass beads size used were in the range of 22 to 163 μm. The experimental results showed that water–based mud with glass beads experiencing 41% reduction of coefficient of friction (CoF) compared to water–based mud without glass beads The presence of 4 ppb of glass beads in water–based mud was found to have given the optimum rheological properties and lowest fluid loss than mud without glass beads and with 2 ppb and 6 ppb of glass beads. The experimental results also revealed that carbolite has the potential to be used as a Lubricating Agent in water–based mud. Key words: coefficient of friction; carbolite; glass beads; Lubricating Agent; water–based mud
Takehiro Hirose - One of the best experts on this subject based on the ideXlab platform.
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Graphite as a Lubricating Agent in fault zones: An insight from low‐ to high‐velocity friction experiments on a mixed graphite‐quartz gouge
Journal of Geophysical Research, 2013Co-Authors: Kiyokazu Oohashi, Takehiro Hirose, Toshihiko ShimamotoAbstract:[1] Graphite is a very low friction material, often enriched within fault zones due to mechanical or chemical processes. The effects of weak minerals on the strength of faults have been examined by friction experiments on bimineralic mixtures. However, previous experiments were conducted with limited shear strains, even though applied shear strains and textural developments had already been signaled as significant factors in the weakening of faults. We therefore conducted large-displacement, low- to high-velocity friction experiments with graphite-quartz gouges, to determine how much graphite is needed to reduce frictional strength, and to examine how textures contribute to the strength reduction of a mature fault at various slip rates. We found that the coefficients of friction of the gouges decrease nonlinearly with increasing graphite fraction for any given shear strain and slip rate, decreasing first with 5–20 vol% graphite, then reaching similar frictional levels to pure graphite with 30–50 vol% graphite. The nonlinear weakening trends can be fitted by sigmoidal curves. The weakening with 10–30 vol% graphite is associated with zones of slip-localization and the development of a graphite-lubricated penetrative slip surface(s). With increasing shear strain, the relationship between strength and graphite fraction evolves abruptly from an early gentle curve to a sigmoidal curve, and the frictional strength drops significantly even with small amounts of graphite (~10 vol%). Our results highlight the importance of shear strain and textural developments on weak faults, not only with respect to graphite, but also other fault lubricants such as the phyllosilicates.
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graphite as a Lubricating Agent in fault zones an insight from low to high velocity friction experiments on a mixed graphite quartz gouge
Journal of Geophysical Research, 2013Co-Authors: Kiyokazu Oohashi, Takehiro Hirose, Toshihiko ShimamotoAbstract:[1] Graphite is a very low friction material, often enriched within fault zones due to mechanical or chemical processes. The effects of weak minerals on the strength of faults have been examined by friction experiments on bimineralic mixtures. However, previous experiments were conducted with limited shear strains, even though applied shear strains and textural developments had already been signaled as significant factors in the weakening of faults. We therefore conducted large-displacement, low- to high-velocity friction experiments with graphite-quartz gouges, to determine how much graphite is needed to reduce frictional strength, and to examine how textures contribute to the strength reduction of a mature fault at various slip rates. We found that the coefficients of friction of the gouges decrease nonlinearly with increasing graphite fraction for any given shear strain and slip rate, decreasing first with 5–20 vol% graphite, then reaching similar frictional levels to pure graphite with 30–50 vol% graphite. The nonlinear weakening trends can be fitted by sigmoidal curves. The weakening with 10–30 vol% graphite is associated with zones of slip-localization and the development of a graphite-lubricated penetrative slip surface(s). With increasing shear strain, the relationship between strength and graphite fraction evolves abruptly from an early gentle curve to a sigmoidal curve, and the frictional strength drops significantly even with small amounts of graphite (~10 vol%). Our results highlight the importance of shear strain and textural developments on weak faults, not only with respect to graphite, but also other fault lubricants such as the phyllosilicates.
Wei Xiaofei - One of the best experts on this subject based on the ideXlab platform.
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water based high corrosion resistance coating with excellent stamping performance and preparing method and application of water based high corrosion resistance coating
2015Co-Authors: Chen Xingyao, Huang Yanyi, Li Yuefeng, Jin Xingju, Wei XiaofeiAbstract:The invention belongs to the technical field of surface corrosion prevention and discloses a water-based high-corrosion-resistance coating with excellent stamping performance and a preparing method and application of the water-based high-corrosion-resistance coating. The coating comprises, by mass, 25-60 parts of water-based resin, 2-8 parts of water-based cross-linking Agent, 0.1-0.5 part of catalyst, 4-10 parts of cosolvent, 0.1-1 part of flatting Agent, 0.1-10 parts of Lubricating Agent, 2-10 parts of water-based toughening resin, 0.1-0.5 part of defoaming Agent, 0.5-3 parts of thickening Agent and the balance water, and the total mass parts of the components are 100 parts. According to the water-based high-corrosion-resistance coating, the water-base resin serves as film forming matter, so that good construction performance is achieved, curing is quick, super corrosion resistance can be obtained when the thickness of the coating is 2-5 micrometers, the performance of resisting neutral salt mist is longer than 2,000 hours, resistance to acid salt mist is longer than 500 h, the corrosion grade can reach 9.8 or higher, and the salt mist resisting performance of the coating is maintained unchanged after stamping or bending is carried out.
