1, pupil
During the infusion process, if the mud level in the wellbore slurry suddenly rises and overflows the casing, then the airdrop suddenly drops and bubbles appear. It should be suspected to be a pupil phenomenon, which can be detected by a sounding hammer. If the depth of the hammer is not attached to the surface of the hammer, it can not be lifted, or the depth of the hammer can not reach the original depth when the hammer is detected. The difference is very large and can be confirmed as a pupil.
The cause of the pupil may be water leakage around the foot of the casing, the water level in the hole is reduced or in the tidal river. When the tide rises, the water level difference in the hole decreases, the original hydrostatic pressure cannot be maintained, and the heavy objects or machine vibrations are piled up around the casing. Can cause pupils.
After the occurrence of the pupil, the cause should be identified, and corresponding measures should be taken, such as maintaining or increasing the water head, removing the heavy object, removing the vibration, etc., to prevent the pupil from continuing, and then sucking the soil in the hole into the hole with a suction machine, if not Continue the pupil to resume normal perfusion. When the pupil is not serious, it can be backfilled to the position above the pupil, and measures such as improving mud performance, raising the water head, and deepening the casing to continue drilling. When the pupil is serious, the borehole should be immediately backfilled with sand or small gravel clamped clay. After a period of time, the cause of the pupil is found and the corresponding measures are taken to re-drill. When the pupil is not deep, the deep-buried tube method can be adopted to re-drill the soil around the tube. [1]
2, the body is skewed
When the hole is deflected or bent, the cause should be analyzed and processed. Generally, the drill cone can be repeatedly swept in the skew to make the borehole straight; when the skew is severe, the sticky soil should be backfilled to the skew, and then drilled after the compaction. Source: Beautiful editors of the exam
3, reaming, shrinking holes
In the case of reaming or shrinking cavities, measures should be taken to prevent boring and to prevent the drill cone from swinging too large. The shrinkage hole is caused by the wear of the drill cone, the welding repair is not timely or due to the soft soil and clay mudstone in the formation. The former should pay attention to the timely repair of the drill cone, and the latter should use the high quality mud retaining wall with low water loss rate. . When the shrinkage cavity has occurred, it is preferable to repeatedly sweep the hole up and down with the drill cone to enlarge the hole diameter.
4, paste drill, buried drill
Drilling and embedding often occur in rotary drilling and impact drilling in positive circulation (including submersible drilling rigs). In this case, the mud consistency, the entrance and exit of the drill slag, the inner diameter of the drill pipe, and the slagging equipment should be checked and calculated, and the appropriate footage should be controlled. If the drill is severely drilled, the drill cone should be stopped and the drill slag should be removed.
5, card drill
Card drilling often occurs in impact drilling. After the card is drilled, it should not be lifted. It should be lifted lightly. When the light is lifted, it can be impacted by a small impact drill cone or by drilling and sucking to loosen the drill residue around the drill cone.
6, drop the drill
When dropping the drilled material, it should be quickly salvaged with tools such as salvage forks, hooks, rope sets, etc. If the falling body has been buried by the mud, the mud sand should be removed first according to the above-mentioned articles, so that the salvage tool can be salvaged after contacting the falling body.
Under no circumstances should construction personnel enter the borehole without a protective tube or other protective equipment to handle the fault. When it is necessary to drill holes in the protective casing or other protective facilities, it is necessary to check that there are no harmful gases in the holes, and to prepare for safety facilities such as anti-virus, anti-mite, anti-smashing and burying.
Tabular Spar,Natrual Stone,Pumice Stone
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