This paper analyses and expounds :thetechniques relating to foam drilling in Clayey Crackformation and by down hole hammer in cracky hardrock formation;

• 分析论述了粘土质裂隙地层空气泡沫钻进的有关工艺；裂隙发育硬岩地层空气泡沫潜孔锤钻进的有关工艺；