The speed at which coalbed methane wells are drained affects their productivity. If drained too quickly, fractures in the coal reservoir can close up, reducing gas production. Slow drainage is key to prevent damage to the reservoir. A well in Jiaozuo Mining area couldn't produce methane due to rapid water reduction. The best rate for lowering the liquid level is 5-10 meters per day before a critical pressure point, then 2 meters per day after.