URB 2,5А Drilling Rig Control System, except some levers, is placed at the
The control system includes (Drawing 19):
- pedal No.2 mounted at the mast leg – controls engine friction;
- gearbox lever No.13 – switches three transmissions;
- rotary lever (10);
- lever No.11 – controls drawworks drive and worm reduction gearbox;
- levers (7 and 8) of frictions of the left and right drawworks drums;
- lever No. 6 of feed unit friction clutches;
- lever No. 9 – actuates the drilling pump;
- lever No.3 - for engine gas control;
- lever No.12 – controls mast raising pump;
- toggle switch – controls the power takeoff attachment via vehicle engine.
Control elements (excluding pedal No.2 of engine friction control, lever No.3) are the bars with forks; the forks adjust the bars length. The bar length should match the idle run position when setting control handles on the locks.
When the mast is raised insert the kelly bar with sealing through the rotary table; fix the drill bit at the end of the kelly bar. Place the clack valve into the receiver with flush fluid, check downstream line joints, prepare circulating system, start up and warm up the vehicle engine.
Switch on the 5th gear, press clutch pedal by toggle switch I and
actuate power takeoff for drilling rig.
All other operation is performed from the driller station in the following order:
- actuate the engine clutch by pressing pedal No.2
- switch on the mud pump drive by lever No.9
- increase the engine speed to 1800 min-1 by lever No.3 and release pedal No.2. In this case the mud pump is actuated. If in a minute the pump doesn’t supply the drilling fluid stop the pump and flood the suction valves;
- as soon as the drilling fluid has started circulating switch off the clutch, decrease the engine speed by lever No.3, choose the necessary gearbox gear by lever No.13 and actuate the rotary by lever No.10;
- when the engine speed is 1800 min-1 gradually release clutch pedal; in this case the rotary starts kelly bar rotation;
- slowly lower the tool by lever No.4 or 5 beginning the well drilling.
To stop well drilling:
- press the engine clutch pedal;
- decrease engine shaft speed;
- switch off the pulley of mud pump drive by lever No.9;
- turn off the rotary by lever No.10.
To turn on the drawworks:
- disengage the engine clutch by pedal No.2;
- turn on the drawworks shaft by lever No.11;
- slowly release clutch pedal, increase engine shaft speed;
- slowly switch on the drawworks drum friction by lever No. 7 or 8 (depends
on the swivel suspension) and begin to raise the tool
To stop tool lifting slow down the drawworks drum by levers No. 4 and 5 simultaneously and disengage the friction. Always operate the drawworks drum and stop the tool lifting smoothly.
To remove the kelly bar out of the rotary turn the rotary bushing so that its nibs got out of the slots and set opposite rotary table slots. At the same time turn on the drawworks friction and release the brake of the drums; carefully remove the kelly bar together with the bushing.
The operation of the tool feed unit is performed in the following way:
- brake the drawworks drum and run tools to the bottom;
- switch off the worm reduction gearbox and feed unit friction; it creates
necessary bit load. The load adjusting is realized by means of periodical
friction switch. When switching off the feed unit brake the drawworks drum and
let the drilling tool to work up the bottomhole till unloading; afterwards
switch off the feed unit reduction gearbox by lever No.11.
Actuation of the drawworks shaft and worm reduction gearbox is blocked. The lock excludes their simultaneous functioning. The feed unit is used also for emergency tools lifting in case of engine malfunction. The lifting is realized manually by rotating worm shaft.