Electric Drilling Rigs

 DC and drive drilling rigs are driven by AC-SCR-DC and AC-DC-AC respectively so as to achieve intelligent control over the rigs. A rig is powered by a diesel generator set, and a drawworks is provided with a hydraulic brake pad and an auxiliary Eaton brake. Winches, drilling pumps, and rotary tables all adopt independent electric drive and stepless speed regulation (rotary tables may also adopt combination drive). The derrick is in K-shaped structure, and the base in swing-up or case block type structure, both of which (if any, the latter shall be of swing up type) are installed at a lower position and hoisted as a whole. The drilling control room imposes centralized control so that rigs are delivered automatically. An AC variable-frequency drilling rig provides dynamic braking.