With the improved drilling fluid and the techniques of under-balanced drilling and pinnate horizontal drilling, the damage from drilling operation can be minimized on the coal-bed gas reservoirs.

• 应通过改善钻井液、采用欠平衡钻井和羽状水平井钻井技术，最大限度地降低钻井工程对煤层气储层造成的伤害；