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Summary: Chemical stimulation is a potential technology for enhancing coal permeability. Current research focuses on developing efficient chemical stimulation techniques and understanding the mechanisms of permeability enhancement. Laboratory studies have shown that acidising, oxidizing, organic solvent extraction, and electrochemistry stimulation techniques can improve coal permeability. Factors such as coal composition, pore-fracture structure, chemical reagent type, precipitation formation, in-situ stress, and water blocking influence the efficiency of permeability enhancement. The field application of chemical stimulation techniques is still limited, and future research should investigate their feasibility and consider the synergistic effects of chemical and physical stimulation techniques.
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