岩金钻探的某些浅部松散或胶结层，采用塑料管与钢套管配合护壁，即外层管用塑料管代替一次性投入使用，内层管沿用钢套管隔离保护，有效地降低了钻探成本，为“以塑代钢”综合治理复杂地层积累了经验。 Rock drilling some of the loose or cement shallow layer, the plastic pipe and steel casing with the protective wall, that is, instead of a one-time use of plastic outer tube put into use, the inner tube along the steel casing isolation protection, effectively reducing the drilling Cost, accumulated experience in the “comprehensive management of complex formations in the form of steel instead of plastic.”