drilling rig,DC drilling Rigs,drilling machinery Model:ZJ50D, ZJ70D Nominal drilling depth, m:5000,7000. 1)DC Rig adopts AC-SCR-DC drive mode, using DC motors to drive drawworks, rotary table and mud pump, realizes stepless speed regulation to satisfy completely the drilling technology requirements.2)K-type derrick (mast) and swing-up substructure, the drill floor height 9m or 10.5m, and drill ...