Significance of Determining the Extraction Radius for Mine Safety and Efficient Resource Development

Area of Science:

• Geosciences
• Energy Engineering
• Mining Engineering

Background:

• Coalbed methane (CBM) extraction is vital for mine safety and clean energy.
• Factors influencing CBM extraction radius are numerous, but their interactions and precise impact are not fully understood.

Purpose of the Study:

• To simulate and determine the effective extraction radius of CBM boreholes under various influencing factors.
• To identify major influencing factors and their interaction effects on CBM extraction radius.
• To construct a predictive calculation model for the effective extraction radius.

Main Methods:

• COMSOL simulations were employed to model CBM extraction radius.
• Sensitivity analysis and response surface methodology were used to identify key factors.
• A calculation model was developed based on factor interactions and their impact on extraction radius.

Main Results:

• Initial gas pressure, coal thickness, and initial permeability are the most significant factors affecting CBM extraction radius.
• Significant interactions were found between initial gas pressure and initial permeability/extraction time, with higher gas pressure inhibiting other factors' impacts.
• The effective extraction area typically forms a vertically expanding oval shape, influenced by coal seam thickness.

Conclusions:

• A validated model accurately predicts CBM effective extraction radius, with a case study showing close agreement between calculated and measured values.
• Optimizing CBM extraction requires careful consideration of initial gas pressure, coal thickness, and permeability.
• Further research into factor interactions can enhance clean energy resource recovery and mine safety.