Drilling accidents may occur in various drilling methods. The pupil is characterized by a sudden drop in the water level in the hole, a fine blisters in the hole, a significant increase in the amount of slag, and a significant increase in the load on the rig.
1. The mud weight is not enough and other mud performance indicators do not meet the requirements, so that the hole wall does not form a solid mud:
2. Since the water or mud is not replenished in time after the slag is slag, or the tidal water of the river rises, or the pressurized water appears in the hole, or the borehole passes through a strong permeable layer such as gravel, the water in the hole is lost, and the height of the water head in the hole is insufficient;
3. The casing is too shallow, the lower end of the hole leaks, collapses or the ground near the hole is soaked and soaked by water, or the rig is placed on the casing. The hole collapses due to vibration and expands into a larger hole.
4. Drill in the soft sand layer, the footage is too fast:
5, catch the drill cone drilling, the swing speed is too fast, the idle time is too long
6. The impact (catch) cone or the slag slag cylinder is dumped, hitting the hole wall, or the boulder, probe stone and explosive in the blasting treatment hole are too large, causing excessive vibration;
7. The water head is too large, so that the hole wall seeps or the bottom of the casing forms a reverse perforation.
8. After the clearing of the hole, the specific gravity and viscosity of the mud are reduced. 'The air suction machine clears the hole. After the mud is sucked away, the water is not replenished in time, so that the water level in the hole is lower than the groundwater level. The clearing operation is improper, and the water supply pipe directly washes the hole wall. Clear the pores for too long or pause for too long after clearing the pores.
9. Collide the wall of the hole when hanging into the steel frame.
1. When drilling in loose silt or drift sand, the progress speed should be controlled, and the mud with larger specific gravity, drilling degree and colloidal rate should be selected, or the cat soil with the mixed egg (egg) stone should be injected, and the low hammer impact can be used. Drilling earth paste and tablets (egg) stone squeeze into the wall of the hole to function as a retaining wall.
2, flood season or high tide, when the water level changes too much, should take the rise of the protective tube, increase the water head, or use siphons, connecting tubes and other measures to ensure that the water head is relatively stable.
3. When the orifice collapses, the casing can be removed immediately and the borehole can be backfilled, and the casing can be reburied and drilled again.
4. If the hole collapses, first determine the collapse position, backfill sand and cat soil (or gravel and loess) mixture to the pupil above 1--2m, if the pupil is serious, all backfill, after the backfill is densely deposited, Drilling in.
5. Strictly control the stroke height and the amount of explosives.
6. When clearing the hole, special personnel should be appointed to replenish water to ensure the necessary head height in the borehole.
1. A large arc or probe stone is encountered in the borehole;
2. At the junction of the soft and hard stratum with inclination, or drilling in the sand and gravel layer with large particle size, the bit is unevenly stressed.
3. If the hole is enlarged, the bit swings to one side;
4. The rig base is not placed horizontally or produces uneven subsidence:
5, Drill Pipe
Bending, joint is not correct
1. When installing the drilling rig, make the turntable and bottom sit horizontally: the lifting pulley edge, the fixed drill pipe bayonet and the casing center should be on a vertical line, and check the correction frequently.
2. Since the active drill pipe is long and the upper swing is too large when rotating, a guide frame must be added to the drill frame to control the water supply head on the drill pipe so as to drill in the guide frame.
3. The drill pipe and joints should be inspected one by one and adjusted in time. When the active drill pipe is bent, the jack should be straightened in time.
4. When drilling in inclined soft and hard formations. The drill pipe should be hung with a drill rod to control the footage and drill at low speed. Or backfill the tablets and pebble before drilling.
5. After ascertaining the position and deflection of the borehole, it is generally possible to hang the Drill Bit up and down repeatedly at the deflection to make the borehole straight. When the deflection is severe, the sand-drilling soil should be backfilled to the skewed position, and the drilling should continue after the sedimentation is compacted.
6. When impact drilling, the gravel and loess should be backfilled and then drilled and compacted. If the deflection is severe, a small amount of explosive blasting may be set at the beginning of the deflection, and then backfilled with sand and gravel to the position above lm. Drilling.
Drilling and falling objects may occur in various drilling methods.
1. Strongly twisting when the card is drilled, and improperly operating the wire rope or drill pipe;
2. Poor drill pipe joint or slippery wire;
3, the motor wiring is wrong, so that the rig should not reverse, the drill pipe is loose;
4. The impact quality of the impact bit alloy sleeve is poor, and the wire rope is pulled out;
5. The welding parts such as the steering ring and the steering sleeve are disconnected;
6. The number of wire ropes connected to the wire rope and the drill bit is insufficient or slack, or the wire rope is too old and there are too many broken wires;
7, the operation accidentally fell on the wrench crowbar and other things.
1. Before opening the drill, the inner part of the hole should be removed. The sporadic iron piece can be used to draw larger objects and the drill can also be used to punch the cone. Then cover the mouth of the tube;
2. Always check drills, drill pipes, wire ropes and connecting devices;
3. In order to facilitate the salvage of the falling cone, the fishing ring can be pre-welded on the punching cone, salvage the bar or bundle a few rounds of wire rope on the cone.
After the drill is broken, the situation should be ascertained in time. If the drill cone is buried by the sediment or the borehole soil, the hole should be cleaned first. Make the fishing tool accessible to the drill cone. There are several types of salvage tools: salvage fork, salvage hook, salvage looper, partial hook and drill cone flat hook, salvage forceps: