Abstract
Structured coal is characterized by tectonically caused features (e.g. a cataclastic or mylonitic structure with small particle sizes), which is crucial for coal exploitation and coalbed methane (CBM) development. To quantitatively identify high-resolution coal structures, a destruction F-Index that determined through multiple geophysical logging with principal component analysis (PCA), was proposed to divide coal structure into five types: I-undeformed, II-transitional, III-cataclastic, IV-granulated and V-mylonitized coals. The undamaged coals (including types I and II) that dominate the target area are normally concentrated in low-angle and gentle strata, while the structured coals (including types III, IV and V) are only distributed along syncline axial parts and fault zones. Furthermore, a deformation D-Index, to quantify the coal deformation degree in single well, was set from 1 to 5, which indicates that the larger the number is, the higher the degree is. The results showed that a negative relation between parting (normally shales or mudstones) content and D-Index, which suggests that the parting provides the resistance for coal seam deformation. Furthermore, coal deformation degree increases with the burial depth and thickness of coal seam. From the Hercynian orogeny to Himalayan orogeny, coal seams of the research area have experienced three phases of deformation. Most structured coals that distribute along syncline axial parts and fault zones formed during this process, and the undamaged coals are distributed in the internals of extensional tectonic belts (e.g. graben and horst). In addition, for a local area, the regional tectonic styles may also determine the structured coal distribution.
| Original language | English |
|---|---|
| Pages (from-to) | 210-222 |
| Number of pages | 13 |
| Journal | Journal of Natural Gas Science and Engineering |
| Volume | 51 |
| Early online date | 13 Feb 2018 |
| DOIs | |
| Publication status | Published - 31 Mar 2018 |
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Keywords
- Coal structure
- Geophysical logging
- Novel methodology
- Quantitative evaluation
ASJC Scopus subject areas
- Energy Engineering and Power Technology
Cite this
Evaluation of structured coal evolution and distribution by geophysical logging methods in the Gujiao Block, northwest Qinshui basin, China. / Wang, Yingjin; Liu, Dameng; Cai, Yidong; Yao, Yanbin; Zhou, Yingfang.
In: Journal of Natural Gas Science and Engineering, Vol. 51, 31.03.2018, p. 210-222.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evaluation of structured coal evolution and distribution by geophysical logging methods in the Gujiao Block, northwest Qinshui basin, China
AU - Wang, Yingjin
AU - Liu, Dameng
AU - Cai, Yidong
AU - Yao, Yanbin
AU - Zhou, Yingfang
N1 - This research was funded by the National Natural Science Fund (grant nos. 41602170 and 41711530129), the Research Program for Excellent Doctoral Dissertation Supervisor of Beijing (grant No. YB20101141501), the Fundamental Research Funds for Central Universities (Grant no. 35832015136) and Key Project of Coal-based Science and Technology in Shanxi Province-CBM accumulation model and reservoir evaluation in Shanxi province (grant no. MQ2014-01).
PY - 2018/3/31
Y1 - 2018/3/31
N2 - Structured coal is characterized by tectonically caused features (e.g. a cataclastic or mylonitic structure with small particle sizes), which is crucial for coal exploitation and coalbed methane (CBM) development. To quantitatively identify high-resolution coal structures, a destruction F-Index that determined through multiple geophysical logging with principal component analysis (PCA), was proposed to divide coal structure into five types: I-undeformed, II-transitional, III-cataclastic, IV-granulated and V-mylonitized coals. The undamaged coals (including types I and II) that dominate the target area are normally concentrated in low-angle and gentle strata, while the structured coals (including types III, IV and V) are only distributed along syncline axial parts and fault zones. Furthermore, a deformation D-Index, to quantify the coal deformation degree in single well, was set from 1 to 5, which indicates that the larger the number is, the higher the degree is. The results showed that a negative relation between parting (normally shales or mudstones) content and D-Index, which suggests that the parting provides the resistance for coal seam deformation. Furthermore, coal deformation degree increases with the burial depth and thickness of coal seam. From the Hercynian orogeny to Himalayan orogeny, coal seams of the research area have experienced three phases of deformation. Most structured coals that distribute along syncline axial parts and fault zones formed during this process, and the undamaged coals are distributed in the internals of extensional tectonic belts (e.g. graben and horst). In addition, for a local area, the regional tectonic styles may also determine the structured coal distribution.
AB - Structured coal is characterized by tectonically caused features (e.g. a cataclastic or mylonitic structure with small particle sizes), which is crucial for coal exploitation and coalbed methane (CBM) development. To quantitatively identify high-resolution coal structures, a destruction F-Index that determined through multiple geophysical logging with principal component analysis (PCA), was proposed to divide coal structure into five types: I-undeformed, II-transitional, III-cataclastic, IV-granulated and V-mylonitized coals. The undamaged coals (including types I and II) that dominate the target area are normally concentrated in low-angle and gentle strata, while the structured coals (including types III, IV and V) are only distributed along syncline axial parts and fault zones. Furthermore, a deformation D-Index, to quantify the coal deformation degree in single well, was set from 1 to 5, which indicates that the larger the number is, the higher the degree is. The results showed that a negative relation between parting (normally shales or mudstones) content and D-Index, which suggests that the parting provides the resistance for coal seam deformation. Furthermore, coal deformation degree increases with the burial depth and thickness of coal seam. From the Hercynian orogeny to Himalayan orogeny, coal seams of the research area have experienced three phases of deformation. Most structured coals that distribute along syncline axial parts and fault zones formed during this process, and the undamaged coals are distributed in the internals of extensional tectonic belts (e.g. graben and horst). In addition, for a local area, the regional tectonic styles may also determine the structured coal distribution.
KW - Coal structure
KW - Geophysical logging
KW - Novel methodology
KW - Quantitative evaluation
UR - http://www.scopus.com/inward/record.url?scp=85042936423&partnerID=8YFLogxK
U2 - 10.1016/j.jngse.2018.01.022
DO - 10.1016/j.jngse.2018.01.022
M3 - Article
VL - 51
SP - 210
EP - 222
JO - Journal of Natural Gas Science & Engineering
JF - Journal of Natural Gas Science & Engineering
SN - 1875-5100
ER -