• Cooperated with SIMENS, the rig provides with the state of arts VFD technology :
  • Vector control NC(Numerical Control) VFD technology
  • Feedback breaking
  • Dynamic breaking
  • Field bus  communication
  • Adopting 600v general power widely used in international Oilfield drilling fields
  • Main drive adopts “one to one” control.
  • Adopting DTC and Pubic DC Bus of ABB
• Better drilling performance of drilling rig can be obtained by the application of VFD technology. Wide speed adjustable range and control technique can reduce greatly transmission structure. Compared with DC AC-SCR-DC, drawworks is changed to single-speed gear transmission from four shift of chain transmission, removed shift device、drum clutch and electromagnetic eddy brake, driller control is simple and dependable, greatly reduces the maintenance on the rig; also can reduce 27% weight and 32% volume of drawworks.
• NC close-loop control of drawworks speed is combined with NC close-loop control of traveling position, can realize total process control of drilling trip in and trip out, integrated control technique is applied to improve greatly safety and drilling speed, speed of tripping in increased 16%, speed of trip out increased 30%, auto-drilling system is applied to increase 37% drilling efficiency, can greatly increase drilling efficiency and improve reliability of operation.
• Electric transmission system with NC variable frequency speed regulating are safety in operation, stable in parameter, simple in adjustment, high precision in speed. Testing power factor of Converter grid is high, the comprehensive power factor of  AC VFD transmission system is higher more than 20% than DC system, so energy consumption is small, oil consumption reduce 25%,  economical efficiency of operation is good. The whole NC variable frequency control system possess large commutation interface and expanded development capacity, can realize system’s automation, information and network, so VFD electric drive is develop tendency of drilling rig’ s drive system in drilling operation . 
• VFD electric driven is simple in structure, reliability in operation, less expenses in maintenance. AC asynchrony motor is liable to realize high speed and large power, so adopt high-speed, large power, wide frequency AC motor and Variable frequency control system can realize one shift gear transmission in drawworks, F1600 mud pump is driven by one set motor, stepless speed range 0-100%, and DC SCR electric transmission system can’t be realized.
• Drawworks with DC SCR transmission and rotary table shall be changed to realize forward and reversal by contractor , adopt auxiliary brake when braking. And vector control can make motor operation in fourth quadrant, drawworks’ forward and reversal can be realized smoothly by preset; energy of tripping in make dynamic brake by brake unit and auto access of brake resistance, stable in function , replace widely used auxiliary brake device.
• Driller’s control system
  • Intelligent driller control by adopting advanced VFD control technology and integrated design of PLC of electric transmission system, touch screen, air system, electric system, fluid system, and drilling parameters.
  • Adopt  PROFIBUS-DP site fieldbus, realize electricity, air, liquid, mechanical tool, industry monitoring, intercom system, drilling parameter integral design, all can by controlled by electric, realize driller’s console monitoring all drilling rig. Special electric control cabin is designed in Driller house, adopt positive pressure explosion proof structure, can meet explosion proof requirement of API RP500 SPEC I class 2 area. 
  • Control rod is used in Speed regulating control of drawworks, installed at the front of driller’s control box to operate conveniently. With continuous speed regulating function in tripping in and tripping out and hovering function in zero speed.

Parts and characteristic: 

• Industry computer
• Redundant PLC
• HMI technology
• Intelligent remote driller control
• CCTV monitoring
• State control
• Design of positive pressure explosion-proof
• Closed, anti-shower, removab

• Main Functions of Driller’s Console
  • Trip in and trip out drill string and position control of traveling block
  • Control of rotary table for the running and torque
  • Automatic braking in the event the main motors and motor for automatic drilling system fails
  • Soft stop and crown protection
  • Automatic control during the drilling operation
  • Control of wellhead mechanical tools
  • PLC control for air system, hydraulic system and disc brake
  • Automatic bit feed and hand-controlled bit feed
  • Control of disc brake and dynamic braking system
• Take the advantage of all-digital VFD system for communication and network, make all subsystems as an Ethernet via fieldbus system to realize the control of all system. Thus, it establishes a complete automatic control system for drilling rig according to the design principle of intelligence, humanization and integration for driller. Also, it can realize Internet control through the expansion and update of system and provide the feasibility for the remote network control of drilling operation in the oil field.
• HSE optimized and humanity design
  • When electric system, motors, independent automatic drilling system, and lubricating system of drawworks gearbox fails, emergency braking of hydraulic disc brake can be automatically achieved to assure that the rig can run reliably.
  •  VFD control system is equipped with redundant circuits, with which the rig can run normally when the main system fails.
  • Integral mechanics-electric, ambient, and safety is considered on the driller’s console layout. It features friendly human-machine interface and humanity design.
  • The rig is equipped with safety devices such as slide ladders, escape system, derrick climbing assistant, safety chain, and anti-falling devices. 
  • There are safety operation boards at high operation positions and safety measures at equipment higher than human body.
  • Mud recycle system: Mud channels and recycle devices is designed at well head.

Basic Parameters:

• Model	ZJ70DB(2000hp AC rig)
  Nominal drilling depth (4 ½ drill pipe)	7000m(23000ft)
  Max. hook load	4500KN(1,000,000lbs)
  Rated input power of drawworks	1600KW(2000HP)
  Drawworks speed	1+1R        stepless speed regulation,          Single speed gear drive
  Drilling line diameter	38mm(1-1/2″)
  Effective height & model of mast	45.5m/K(149ft)
  Floor height/substructure type	10.5m(34.5ft)/one rope swing-up
  Opening of rotary table	37 1/2"
  Speed of rotary table	1+1R stepless speed regulation,     independent drive
  Rated power x number of mud pump	1600hp×3
  Electric drive model	AC-DC-AC  “one to one” variable frequency drive
  Main generator set	4×1900kVA
  Variable frequency unit	6+1