What Is a Rig Mat?

Rotary drilling rig is a rotary drilling rig for geological drilling.

Rotary drilling rig

Subject: Drilling Engineering

Word: Turntable Drill

English: mtmT drill

Explanation: A rotary drilling rig for geological drilling. Since its main turning mechanism is a turntable, it is called a turntable drilling rig. The turntable is a rotating part with a square hole in the center, and it drives the drilling tool in the hole to rotate through a square drill pipe. When lifting the drilling tool, the turntable is a mechanism for unscrewing and unloading the drilling tool, which can reduce labor intensity and is conducive to safe production. The turntable itself cannot control the feed, so when drilling shallow holes, press with a wire rope or a chain; when drilling deep holes, use a winch to adjust the weight of the drill tool at the bottom of the hole to control the bottom pressure. Rotary drilling rigs have a narrow range of drilling directions, and generally can only drill holes from 70 ° to 90 °.

First, the installation of the rig

1. Before installing the rig, a thorough inspection of the local terrain, geology, hydrology, meteorology, and floods should be carried out. Ground foreign objects should be cleaned up, and the foundation of the site should be checked for underground pipelines and cables. If necessary, please contact the relevant unit for advance removal. The distance between the rig and the high-voltage wire shall comply with the relevant regulations.

2. The foundation of the drill rig should be compacted and leveled. A sleeper shall be laid under the drill rig of a tire-type rig to lift the tire away from the ground. The length of the sleeper shall not be less than 4m. After the drilling rig is lifted up, keep the whole machine in a horizontal position.

3. The installation of the rig and the assembly of the drill must be carried out in strict accordance with the instructions. The rig should be erected or lowered under the command of the captain or skilled workers. The division of labor should be clear, each should understand their own responsibilities, be familiar with the surrounding environment, and the way of command signal contact. It is not allowed to stand the rig in heavy rain, heavy snow and strong winds above the sixth level.

4. The lifting center of the derrick, the hole of the drilling rig and the center of the well pipe shall be on the same vertical line, and the deviation of the center of the drill pipe shall not be greater than 20mm.

2. Inspection before commencement

1. Check the installation and tightening of each part of the rig, and find that they should be tightened in time when they are loose; there should be protective covers for the rotating parts and the drive belt; the wire rope should be intact;

2. Check the oil level of each running assembly, and fill the lubricating parts with lubricating oil and grease according to the instructions.

3. Check whether the electrical equipment is complete and the circuit configuration is intact, and solve the problem in time.

4. Check that the pipe joints are complete and sealed, and perform necessary tightening work.

5. Check that there is no air leakage, oil leakage, or water leakage in all parts.

6. Remove the obstacles within the operating range of the drilling rig, and check in detail whether there are tools, accessories, etc. in the well protection tube. After the inspection, cover the working platform tightly to prevent the tools and accessories from falling into the well hole during operation.

7. Set the control handles of each part to the neutral position, and manually check whether each part is flexible. Finally, close the motor and check the rotation direction of the motor. If it is found to be reverse, the motor wiring should be changed. After confirming that everything is normal, you can start the machine officially.

8. The quality of the drill and drill pipe connection threads must be good, and the sliding buckle must not be used in a slack manner. The drill must be replaced with a new one. The alloy head must be welded firmly without cracks. 3mm thick washers can be added at the joint of the drill bit and drill rod to facilitate the removal of the drill rod after work.

Third, the precautions in use

1. When a rotary drilling rig equipped with a mud pump is started, the slurry should be fed first and then drilled; when the drilling is stopped, the drilling should be stopped first and then the slurry should be stopped. The mud pump should be supervised by someone, and the mud supply should be closely connected with the rig operator, observe the mud quality (specific gravity, sand content, colloid rate, viscosity) and the height of the slurry, and measure and adjust it at any time. The concentration should be appropriate, and the slurry surface should not exceed 0.5m below the orifice. Especially when the drilling is stopped, it is necessary to replenish the slurry in time when it is found that the slurry is leaked, and the drill collars and debris in the sedimentation tank should be removed in time to keep the mud pure. So as not to collapse the hole.

2. When the BRM series rotary drilling rig is started, the air is supplied first, idling, and then fed in. The drill bit is pulled up slightly away from the bottom of the hole to avoid stuck.

3. During the drilling phase, the drilling pressure should be light and the speed should be slow.

4. During the drilling process, according to the geological conditions and drilling depth, select an appropriate drilling pressure and speed to feed uniformly. When drilling in uneven geology or at the intersection of rock formations, the drilling pressure and speed should be reduced to slow down the feed rate. When the drill bit enters the clay layer, measures should be taken to eliminate the phenomenon of paste drilling, and at the same time, use low speed operation to prevent the motor from being burned. When drilling concrete under water, emergency measures should be taken to prevent damage to the rig caused by iron or foreign objects remaining in the concrete.

5. When shifting the gearbox, stop the car in advance, and then drive it after putting it into gear.

6. When attaching the drill pipe, check in advance whether the seal ring is intact and clean the connection. The connecting bolt is a special bolt and cannot be replaced by other bolts. Any old bolts that have been used should be checked carefully to ensure that there are no fatigue cracks at the transition between the bolt head and the rod before they are allowed to be used again. The connecting bolts must be evenly tightened to ensure the tightness of the joints. Bent drill pipes should be repaired and replaced in a timely manner.

7. Before drilling and during drilling, check and observe the operation of the systems such as rock breaking, slewing, lifting, hole washing and drainage. In case of problems, the cause should be promptly identified and handled properly. Fill in construction records carefully.

8. During the drilling process, pay attention to the operation of the machine at all times. In the event of abnormal noises, wire ropes, steering pulleys, jacks and other lifting slings being damaged, faucets leaking, leaking, and other abnormal conditions, stop immediately and investigate the cause before taking measures to continue drilling.

9. When lifting and lowering the drill, be cautious and even in movement. No one should stand under the rig and within 2m around the wellbore, and under the high-pressure hose. The joint between the faucet and the hose must be clamped with double clips and wrapped with iron wire. During the drilling process, the wire rope should be adjusted, and the wire rope should not be allowed to be in an unloaded state when the drill is in the hole, so as to prevent the hole from being enlarged or the drilling deviation. The drill rod must not be lifted during rotation to prevent the slip belt from taking off and causing injury.

10. When the card is stuck (the drilling is blocked), it is not allowed to forcibly lift the drilling tool. You should first try to make the drilling tool move and then slowly raise it. When the card is stuck (drilling is blocked), it can be released by buffering. Find out the cause after dismantling and take measures before drilling.

11. The load capacity and parts of rigs, drill floor flat cars, sealed flat cars, etc. are restricted and must not be overloaded.

12. When the air is used for reverse circulation, its spray nozzle should be covered and the pipe end should be fixed.

13. Frequently monitor the lubrication and add lubricating oil as appropriate.

14. When the drilling footage meets the requirements, the hole bottom elevation should be converted according to the length of the drill pipe. After confirming that it is correct, lift up the drill bit slightly, the speed will change from high to low, and idling for 5-20 minutes. When stopping drilling, stop drilling first and then stop the wind to clean the drill collar at the bottom of the hole.

15. Relocation of the rig should be carried out strictly in accordance with the instructions. A clear division of labor and special personnel to direct.

Fourth, precautions after operation

1. During dismantling and transportation of the transfer hole, the rig should avoid collision and deformation. In order to reduce maintenance and repair during installation and avoid unexpected difficulties encountered during drilling.

2. After the rig is used up, it should be cleaned and maintained in accordance with the instructions.