Synergistic ECBM extraction technology and engineering application based on hydraulic flushing combing gas injection displacement in low permeability coal seams

Shi, Yu; Lin, Baiquan; Liu, Ting; Zhao, Yang; Zhou, Hao

doi:10.1016/j.fuel.2022.123688

Cited by 21 publications

(14 citation statements)

References 54 publications

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“…The deformation of matrix pores is mainly controlled by effective stress, the adsorption swelling effect, and the thermal expansion effect, and it is assumed that the deformation in the matrix is equal to the deformation in pores. Therefore, based on previous studies, the equation for the matrix porosity can be expressed by eq ϕ m = exp [ 1 − ϕ m 0 ϕ normalm 0 true[ normalΔ ε m s + α T ( T − T 0 ) − normalΔ σ m e K normalm true] ] where ϕ m0 is the initial matrix porosity.…”

Section: Modelingmentioning

confidence: 99%

Dynamic Response of Gas Recovery Enhancement Efficiency in Coalbed Methane Displacement by Hot Flue Gas: From the Perspective of Thermo–Hydro–Mechanical–Chemical Coupling

Liu,

Shi,

Liu

et al. 2024

Energy Fuels

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The displacement of coalbed methane (CBM) by hot flue gas is an effective method to enhance gas recovery, but the dynamic response mechanism of gas recovery enhancement efficiency under the influence of the main engineering control parameters (pressure, components, and temperature) of hot flue gas remains unclear. In this study, a thermo−hydro−mechanical− chemical (THMC) coupling model that takes into account the interaction between gas−liquid two-phase fluids, chemical reactions of minerals (dissolution and precipitation), and temperature variations of the reservoir in CBM displacement by hot flue gas was established first. Besides, the mechanism of gas recovery enhancement by hot flue gas was analyzed based on the validated parameters in the THMC coupling model, including gas−liquid two-phase effective pressure in fractures, gas concentration, gas content, calcite content, H + concentration, and spatiotemporal evolution laws of temperature. Furthermore, the variations of the effective breakthrough radius, gas recovery amount, and recovery enhancement efficiency under the influence of different pressures, components, and temperatures of the flue gas were analyzed. Finally, the dynamic response relationship between the main engineering control parameters and the recovery enhancement efficiency in CBM displacement by hot flue gas was further investigated. This study can provide theoretical guidance for the engineering control of recovery enhancement efficiency in CBM displacement by hot flue gas.

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Section: Modelingmentioning

confidence: 99%

Dynamic Response of Gas Recovery Enhancement Efficiency in Coalbed Methane Displacement by Hot Flue Gas: From the Perspective of Thermo–Hydro–Mechanical–Chemical Coupling

Liu,

Shi,

Liu

et al. 2024

Energy Fuels

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“…Different from the previous anisotropic permeability model, Pan and Connell deduced the corresponding permeability model by combining the anisotropy of thermal expansion and sorption swelling of the coal matrix. On the basis of the previous studies, scholars have also developed a series of permeability models for coal and shale unconventional reseviors, which can be found in the literature. − …”

Section: Modelings Of General Performances In Co2-ecbmmentioning

confidence: 99%

Recent Advances and Perspectives of CO₂-Enhanced Coalbed Methane: Experimental, Modeling, and Technological Development

et al. 2023

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Carbon dioxide (CO2)-enhanced coalbed methane recovery (CO2-ECBM) is a critical way to increase methane production and reduce greenhouse gas (CO2 and CH4) emissions. As captured CO2 is continuously injected in the coal seams, a low cost of CO2 sequestration and high efficiency of CH4 recovery can be achieved via the flooding and replacing effects driven by the injected CO2 flow. Scientific insights into the complex process of CO2-ECBM in experiments, modelings, and technological developments need to be made to propose appropriate countermeasures. This review first highlights the progress of CO2-ECBM under laboratory conditions, e.g., the binary gas competitive adsorption and gas displacement experiments in the macroscale and porous structure tests using technologies of nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and computed tomography (CT) in the microscale. Then, the advances of mathematical models for changing in coal permeability and porosity during CO2-ECBM are reviewed, accompanying with the multi-field and multi-phase coupling responses of competitive sorption, diffusion, gas–water seepage, heat transfer, and solid deformation. Furthermore, the field pilot tests of CO2-ECBM in various countries and regions are also covered to reveal the key technical challenges confronted with the development of CO2-ECBM technology. The perspectives in experiments, models, and field pilots of CO2-ECBM are made, which include but are not limited to the following: conducting a core CH4/CO2 flooding test under in situ conditions, modeling CO2-ECBM with real fractures/faults and coal failure, developing a new method for gas migration and leakage monitoring in the field, and enacting relevant standards, laws, and regulations to promote CO2-ECBM.

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“…Yang et al [23] conducted continuous N 2 injection tests in low-gas coal seams, and the response characteristics of gas drainage parameters under different gas injection radii was investigated. Shi et al [24] completed air injection tests based on the application of hydraulic flushing, which showed that even if the drainage entered the exhaustion period, the gas injection could still improve the drainage effect. As continuous air injection may induce the spontaneous combustion of coal and the mobile N 2 generators can provide a stable supply of gas, nitrogen is chosen as the optimal injectant for the field tests of ECGD [23].…”

Section: Introductionmentioning

confidence: 99%

Investigation on Key Parameters of N2 Injection to Enhance Coal Seam Gas Drainage (N2-ECGD)

Yang

Wang

et al. 2022

Energies

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Practice shows that CO2/N2-ECBM is an effective technology to enhance coalbed methane. However, there are few field tests in which the technology is applied to enhance the gas drainage in underground coal mines, and the effect is uncertain. In this study, firstly, the reasons for the decrease of gas drainage efficiency in the exhaustion period were analyzed based on the theory of fluid mechanics. Secondly, the mechanism of N2 injection to enhance coal seam gas drainage (N2-ECGD) was discussed: with the gradual decrease of gas pressure in the drainage process, coal seam gas enters a low-pressure state, the driving force of flow is insufficient, and the drainage enters the exhaustion period. The nitrogen injection technology has triple effects of “promoting flow”, “increasing permeability” and “replacing”. Thirdly, the numerical simulations of the nitrogen pressure on drainage effect were carried out based on the fully coupled model. The results show that the higher the nitrogen pressure, the greater the displacement effect between injection and drainage boreholes, the larger the effective range. Finally, a field test of N2-ECGD was carried out in the Liu Zhuang coal mine in Huainan Coalfield, China. The results show that N2 injection can significantly enhance the gas flow rate and CH4 flow rate in the drainage boreholes, and the coal seam gas content decreased 39.73% during N2 injection, which is about 2.6–3.3 times that of the conventional drainage. The research results provide an important guidance for promoting the application of N2-ECGD in underground coal mines.

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Synergistic ECBM extraction technology and engineering application based on hydraulic flushing combing gas injection displacement in low permeability coal seams

Cited by 21 publications

References 54 publications

Dynamic Response of Gas Recovery Enhancement Efficiency in Coalbed Methane Displacement by Hot Flue Gas: From the Perspective of Thermo–Hydro–Mechanical–Chemical Coupling

Dynamic Response of Gas Recovery Enhancement Efficiency in Coalbed Methane Displacement by Hot Flue Gas: From the Perspective of Thermo–Hydro–Mechanical–Chemical Coupling

Recent Advances and Perspectives of CO₂-Enhanced Coalbed Methane: Experimental, Modeling, and Technological Development

Investigation on Key Parameters of N2 Injection to Enhance Coal Seam Gas Drainage (N2-ECGD)

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Synergistic ECBM extraction technology and engineering application based on hydraulic flushing combing gas injection displacement in low permeability coal seams

Cited by 21 publications

References 54 publications

Dynamic Response of Gas Recovery Enhancement Efficiency in Coalbed Methane Displacement by Hot Flue Gas: From the Perspective of Thermo–Hydro–Mechanical–Chemical Coupling

Dynamic Response of Gas Recovery Enhancement Efficiency in Coalbed Methane Displacement by Hot Flue Gas: From the Perspective of Thermo–Hydro–Mechanical–Chemical Coupling

Recent Advances and Perspectives of CO2-Enhanced Coalbed Methane: Experimental, Modeling, and Technological Development

Investigation on Key Parameters of N2 Injection to Enhance Coal Seam Gas Drainage (N2-ECGD)

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Recent Advances and Perspectives of CO₂-Enhanced Coalbed Methane: Experimental, Modeling, and Technological Development