JSC “Siberian service company”, Moscow.

27.04.2018

news_27_04_18 Retrofitting of electric drives for main machines and automated control system of drilling rig BU 4500/270 EK-BM.
Within February-April 2018 the electric equipment for retrofitting the electric drives of main machines and control system of drilling rig BU 4500/270 EK-BM was produced, shipped and put into operation. Retrofitting of electric drives was executed on basis of existing VFD container K20 at “ASC” manufacturing site. The purpose of retrofit was to replace obsolete and worn-out DC drives and control systems. The electric drives were replaced by up-to-date DC drive of Sinamics DCM type (“Siemens” manufacture).
The following drives were upgraded:

  • main winch drive;
  • emergency winch drive (feed off control drive);
  • drill pump drives;
  • power control unit;
  • handling winch drive.

Automated control systems were totally replaced. “Allen Bradley” controller of LOGIX 5561 type was replaced by “Siemens” controller of S7-315 type. Obsolete and worn-out control consoles for main machines of drilling rig were replaced too, namely:

  • process controller cabinet;
  • driller’s console in explosion-proof housing;
  • control consoles for redundant control circuit;
  • distributed i/o cabinet of a winch;
  • VFD container ventilation and handling winch control cabinet;
  • master controllers for main and handling winches.

The redundant control circuit for drill pumps and feed off control drive was restored to be used in case of failure of automated control system, while the main functions of automated control system were retained:

— Winch drive control:

  • enable/disable of the drive and auxiliary mechanisms, winch speed control during round-trip operations by the driller’s order at limited motor speed, capacity and current values and preset starting, acceleration and braking parameters;
  • application of hoisting block braking while approaching the desired top and bottom centers during round-trip operations, speed limiting while travelling beyond the desired centers;
  • drill stem keeping in a fixed position at zero speed preset;  
  • automatic control of spot-type disk brake during winch stoppage and start-off,  winch speed change by the driller;
  • drill stem weight memorizing, weight on bit control with rate of travel limiting while drilling  at preset values. Weight on bit value is assigned by the driller via the driller’s console;
  • signaling and interlocking.

— Pump drive control:

  • enable/disable of the pump drive and associated auxiliary mechanisms via the driller’s console or pump control console;
  • pump selection;
  • presetting pump speed and acceleration time, motor torque and capacity limitation with introduction of setup values by the driller via the driller’s console;
  • start of motors of supercharger pumps;
  • signaling and interlocking.

Pump control console serves the purpose of:

  • selecting control console – either the driller’s console or pump control console;
  • selecting control mode of supercharger pump;
  • start of pump drive at low speed;
  • start inhibit.

Rotor drive control:

  • enable/disable of the drive, selecting direction of rotation through motor field current commutation via the driller’s console;
  • presetting rotor speed, motor capacity and current limit values;
  • signaling and interlocking.

The new automated control system incorporates a data storage and visualization system implemented with operator desks KP900 of “Siemens” manufacture. Operator desks are installed at pump control consoles and at driller’s console to display the data. Operator desk fulfilling the functions of electrician’s workstation is installed inside VFD container.

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