Characteristics and sedimentary control of a coalbed methane-bearing system in lopingian (late permian) coal-bearing strata of western Guizhou Province

A petrographic coal structure of Late Permian coals from the Liupanshui coalfield, Western Guizhou, SW China, has been distinguished for its novel macro-lithological characteristics. Petrographic, mineralogical and geochemical studies have been conducted for a typical coal sample (No.3 coal, Songhe coalmine, Panzhou County, China) and its geological genesis and significance for coalbed methane (CBM) evaluation is accordingly discussed. It was found that coal is characterized by a banded structure with intensively fractured vitrain sublayers, where a great number of fractures were developed and filled with massive inorganic matter. The study of coal quality, coal petrography, mineralogy and lanthanides and yttrium (REY) geochemistry of the infilling mineral matter (IMM) indicates that this fractured coal structure resulted from the tissues of coal-forming plants or coal matrix shrinkage, as well as the precipitation of calcium rich groundwater and the addition of terrigenous materials. The coal depositional environment and coal-forming plant are considered to have played a role in inducing the special fractures. This provides a scientific reference for the study of CBM for coal with this fractured structure, such as the Late Permian coal from the western border of Guizhou Province, SW China.

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Sealing capacity of siderite-bearing strata: The effect of pore dimension on abundance and micromorphology type of siderite in the Lopingian (Late Permian) coal-bearing strata, western Guizhou province

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2019.03.032 ◽

2019 ◽

Vol 178 ◽

pp. 180-192 ◽

Cited By ~ 1

Author(s):

Yulin Shen ◽

Yong Qin ◽

Geoff G.X. Wang ◽

Qian Xiao ◽

Jian Shen ◽

...

Keyword(s):

Guizhou Province ◽

Late Permian ◽

Sealing Capacity ◽

Pore Dimension ◽

Permian Coal ◽

Western Guizhou

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Mineralogy and Geochemistry of Late Permian Coals within the Tongzi Coalfield in Guizhou Province, Southwest China

Minerals ◽

10.3390/min10010044 ◽

2019 ◽

Vol 10 (1) ◽

pp. 44 ◽

Cited By ~ 1

Author(s):

Baoqing Li ◽

Xinguo Zhuang ◽

Xavier Querol ◽

Natalia Moreno ◽

Linjian Yang ◽

...

Keyword(s):

Southwest China ◽

Guizhou Province ◽

Late Permian ◽

Quartz Content ◽

Eu Anomaly ◽

Marine Influence ◽

Permian Coal ◽

Western Guizhou ◽

Fe Ions ◽

Felsic Rocks

The lowermost Late Permian coal seam (C4 Coal) in the Tongzi Coalfield offers an opportunity to investigate the influence of terrigenous detrital materials from the Qianbei Upland on the mineralogical and geochemical patterns of the C4 Coal. The minerals are mainly dominated by pyrite and, to a lesser extent, tobelite, kaolinite, and calcite, along with traces of Al-oxyhydroxide minerals. The various degrees of marine influence may have resulted in the variation in the amount of Fe-sulfides (e.g., pyrite) and elements having Fe-sulfides affinity. Furthermore, the abundant Fe ions involved in the formation of Fe-sulfides were most likely derived from the claystone on the Qianbei Upland. The tobelite identified in the C4 Coal probably originated from the interaction between pre-existing kaolinite and NH4+ from NH3 released from the thermally affected organic matter at least shortly after the highly volatile bituminous stage under NH4+-rich and K+-poor conditions. The terrigenous detrital materials were derived from two possible sediment-region sources—the Qianbei Upland and Kangdian Upland—which is different from Late Permian coals in Western Guizhou Province. The claystone on the Qianbei Upland may have served as parent rock, as indicated by the presence of the Al-oxyhydroxide minerals as well as low SiO2/Al2O3 ratio (0.66 on average) and low quartz content. Meanwhile, the detrital materials from the Kangdian Upland most likely originated from the erosion of the felsic rocks at the uppermost part of the Kangdian Upland, as evidenced by the high Al2O3/TiO2 ratio (36.0 on average) and the strongly negative Eu anomaly (0.61 on average).

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