Research Article
Open Access
Study on Reservoir Space Characteristics and Gas Storage Mechanism of Low-Rank Coal Reservoir in Junggar Basin
1
Xinjiang Yaxin Coalbed Methane Resource Technology Research Co., Ltd., Urumqi 830011, China
* Corresponding Author:
Yuqing Chen,
[email protected]
Volume 3, Issue 1
2027
Received: 11 May 2026
Revised: 04 August 2026
Accepted: 12 August 2026
Published: 02 September 2026
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CC BY 4.0 License
Article Information
Abstract
The Junggar Basin contains widely distributed Jurassic low-rank coal seams (Badaowan Fm. J\(_1\)b, Xishanyao Fm. J\(_2\)x) with abundant coalbed methane (CBM) resources. Integrating proximate analysis, maceral identification, vitrinite reflectance, low-temperature N\(_2\) adsorption, high-pressure mercury intrusion, and NMR, this study characterizes the petrological properties, pore-space characteristics, and gas storage mechanisms of J\(_1\)b and J\(_2\)x low-rank coals in the Baijiahai-Dinan area. Results show: J\(_1\)b is bright coal (vitrinite: 74.1%-88.3%, R\(_o\): 0.67%), while J\(_2\)x ranges from semibright to dull coal (vitrinite: 57.2%, R\(_o\): 0.71%), corresponding to long-flame coal-lignite stage. J\(_2\)x coal exhibits better reservoir properties (porosity: 9.4%; permeability: 19.64 mD) with well-developed meso/macropores favorable for free-gas storage; J\(_1\)b coal has abundant micropores offering greater adsorption capacity. Low-temperature N\(_2\) adsorption curves classify pores as Type A (cylindrical/slit-shaped), B (parallel-plate/wedge-shaped), and C (closed-end wedge-shaped), with J\(_2\)x showing more diverse pore types and higher meso/macropore proportions. A hierarchical adsorption model for low-rank coal was developed: micropores fill rapidly at low pressure, transition pores approach monolayer saturation, and meso/macropores remain in unsaturated monolayer adsorption. Critical desorption pressures are 3.7-4.7 MPa for J\(_2\)x and 4.5-6.8 MPa for J\(_1\)b. Free-gas storage is controlled by both microscopic pore competition and macroscopic geological conditions. This study provides a key reference for CBM exploration and development in the Baijiahai-Dinan area.
Graphical Abstract
Keywords
junggar basin
low-rank coal
pore space
pore structure
gas storage mechanism
adsorbed gas
free gas
Data Availability Statement
Data will be made available on request.
Funding
This work was supported without any funding.
Conflicts of Interest
Yuqing Chen and Yi Wang are affiliated with the Xinjiang Yaxin Coalbed Methane Resource Technology Research Co., Ltd., Urumqi 830011, China. The authors declare that this affiliation had no influence on the study design, data collection, analysis, interpretation, or the decision to publish, and that no other competing interests exist.
AI Use Statement
The author declares that no generative AI was used in the preparation of this manuscript.
Ethical Approval and Consent to Participate
Not applicable.
References
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APA Style
Chen, Y., & Wang, Y. (2026). Study on Reservoir Space Characteristics and Gas Storage Mechanism of Low-Rank Coal Reservoir in Junggar Basin. Journal of Geo-Energy and Environment, 3(1), 1-15. https://doi.org/10.62762/JGEE.2026.780406
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TY - JOUR AU - Chen, Yuqing AU - Wang, Yi PY - 2026 DA - 2026/09/02 TI - Study on Reservoir Space Characteristics and Gas Storage Mechanism of Low-Rank Coal Reservoir in Junggar Basin JO - Journal of Geo-Energy and Environment T2 - Journal of Geo-Energy and Environment JF - Journal of Geo-Energy and Environment VL - 3 IS - 1 SP - 1 EP - 15 DO - 10.62762/JGEE.2026.780406 UR - https://www.icck.org/article/abs/JGEE.2026.780406 KW - junggar basin KW - low-rank coal KW - pore space KW - pore structure KW - gas storage mechanism KW - adsorbed gas KW - free gas AB - The Junggar Basin contains widely distributed Jurassic low-rank coal seams (Badaowan Fm. J\(_1\)b, Xishanyao Fm. J\(_2\)x) with abundant coalbed methane (CBM) resources. Integrating proximate analysis, maceral identification, vitrinite reflectance, low-temperature N\(_2\) adsorption, high-pressure mercury intrusion, and NMR, this study characterizes the petrological properties, pore-space characteristics, and gas storage mechanisms of J\(_1\)b and J\(_2\)x low-rank coals in the Baijiahai-Dinan area. Results show: J\(_1\)b is bright coal (vitrinite: 74.1%-88.3%, R\(_o\): 0.67%), while J\(_2\)x ranges from semibright to dull coal (vitrinite: 57.2%, R\(_o\): 0.71%), corresponding to long-flame coal-lignite stage. J\(_2\)x coal exhibits better reservoir properties (porosity: 9.4%; permeability: 19.64 mD) with well-developed meso/macropores favorable for free-gas storage; J\(_1\)b coal has abundant micropores offering greater adsorption capacity. Low-temperature N\(_2\) adsorption curves classify pores as Type A (cylindrical/slit-shaped), B (parallel-plate/wedge-shaped), and C (closed-end wedge-shaped), with J\(_2\)x showing more diverse pore types and higher meso/macropore proportions. A hierarchical adsorption model for low-rank coal was developed: micropores fill rapidly at low pressure, transition pores approach monolayer saturation, and meso/macropores remain in unsaturated monolayer adsorption. Critical desorption pressures are 3.7-4.7 MPa for J\(_2\)x and 4.5-6.8 MPa for J\(_1\)b. Free-gas storage is controlled by both microscopic pore competition and macroscopic geological conditions. This study provides a key reference for CBM exploration and development in the Baijiahai-Dinan area. SN - 3069-3268 PB - Institute of Central Computation and Knowledge LA - English ER -
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@article{Chen2026Study,
author = {Yuqing Chen and Yi Wang},
title = {Study on Reservoir Space Characteristics and Gas Storage Mechanism of Low-Rank Coal Reservoir in Junggar Basin},
journal = {Journal of Geo-Energy and Environment},
year = {2026},
volume = {3},
number = {1},
pages = {1-15},
doi = {10.62762/JGEE.2026.780406},
url = {https://www.icck.org/article/abs/JGEE.2026.780406},
abstract = {The Junggar Basin contains widely distributed Jurassic low-rank coal seams (Badaowan Fm. J\(\_1\)b, Xishanyao Fm. J\(\_2\)x) with abundant coalbed methane (CBM) resources. Integrating proximate analysis, maceral identification, vitrinite reflectance, low-temperature N\(\_2\) adsorption, high-pressure mercury intrusion, and NMR, this study characterizes the petrological properties, pore-space characteristics, and gas storage mechanisms of J\(\_1\)b and J\(\_2\)x low-rank coals in the Baijiahai-Dinan area. Results show: J\(\_1\)b is bright coal (vitrinite: 74.1\%-88.3\%, R\(\_o\): 0.67\%), while J\(\_2\)x ranges from semibright to dull coal (vitrinite: 57.2\%, R\(\_o\): 0.71\%), corresponding to long-flame coal-lignite stage. J\(\_2\)x coal exhibits better reservoir properties (porosity: 9.4\%; permeability: 19.64 mD) with well-developed meso/macropores favorable for free-gas storage; J\(\_1\)b coal has abundant micropores offering greater adsorption capacity. Low-temperature N\(\_2\) adsorption curves classify pores as Type A (cylindrical/slit-shaped), B (parallel-plate/wedge-shaped), and C (closed-end wedge-shaped), with J\(\_2\)x showing more diverse pore types and higher meso/macropore proportions. A hierarchical adsorption model for low-rank coal was developed: micropores fill rapidly at low pressure, transition pores approach monolayer saturation, and meso/macropores remain in unsaturated monolayer adsorption. Critical desorption pressures are 3.7-4.7 MPa for J\(\_2\)x and 4.5-6.8 MPa for J\(\_1\)b. Free-gas storage is controlled by both microscopic pore competition and macroscopic geological conditions. This study provides a key reference for CBM exploration and development in the Baijiahai-Dinan area.},
keywords = {junggar basin, low-rank coal, pore space, pore structure, gas storage mechanism, adsorbed gas, free gas},
issn = {3069-3268},
publisher = {Institute of Central Computation and Knowledge}
}
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