... drill low compressive strength,soft formation6)various of model and dimension avaliable7)rubber seal or metal seal8)IADC:437 ... water well, oil field, construction, geothermal, directional boring, and underground foundation work Formation sticky,soft,medium hard,hard formation ... is specializes in drill bits, drill pipe, Mud pump and stabilizers for water well, oil field, construction, geothermal, directional ...