1.The sharp deviation hole is generally caused by geology. Due to the weathering degree of rock layer, uneven rock distribution, etc., the drill pipe is suddenly stuck when the main roll reaches a certain position in the hole, or the drill pipe suddenly leans to one side, indicating a sudden deviation in a certain position in the hole.
2 Slow deviation With the extension of the main roll and the depth of the hole, the first section of the drill pipe moves forward to the barrel and deviates from the center, and the first section of the drill pipe always approaches the barrel in one direction, which indicates that the hole is slowly deviated in one direction, and the closer the hole is biased.
3 Irregular deviation with the drill pipe down, the first drill pipe shaking from side to side, or in the dry hole drilling can directly look at the hole without regular spiral deviation phenomenon, this deviation phenomenon is mostly by the full and strong weathered rock layer, due to the uneven force of the drilling pipe drilling longitudinal deviation.1. Geological geology is the main reason for partial hole. If the geology is loess layer and clay layer, there will be no deviation in the hole. Most of them are caused by geological changes and uneven distribution of weathered rock and rock, resulting in uneven force of the drilling bucket during drilling.2 The main function of the drill bucket is cutting drilling, but it also has the function of guiding and preventing deviation. The pilot tip of the drill center has the positioning function, and the pilot tip can change the drilling order, the number and angle of drilling teethWhether the degree is consistent, whether the height of the side knife or protective strip on both sides of the drill body is the same, these details can make the drill bucket drilling left and right force uniform and prevent deviation.3 operation When there are rocks, drift stones, pebbles, weathered rock layers in the hole, it is necessary to control the floating and pressure mode, if fast drilling will cause sharp deviation hole.
How to prevent partial hole 1 to understand the geological investigation engineering through the geological report, core sampling, geographical environment and so on, a detailed understanding of the geological situation.2 Through the actual verification, the roger bucket can prevent a better deviation than the double bottom sand bucket, because the drilling resistance of the roger ger bucket is small, which can effectively prevent the deviation hole in the pilot drilling method.3 Optimize the drilling bucket as far as possible, so that the drilling bucket can reduce the drilling resistance, especially the central pilot tip has a positioning effect, which can effectively prevent the deviation hole.4 The guide drill pipe can weld a 2-meter long guard cylinder consistent with the aperture diameter above the screw pipe or double bottom drill pipe. By lengthening the drill pipe guide drilling, this method can effectively prevent the deviation hole.5 Operation control floating, pressure, speed and control drilling speed can effectively reduce the deviation.6 The drilling method judges the current geological situation through vibration and load, and changes the drilling method: such as cutting drilling, crushing drilling, moving drilling and grinding drilling, and changing the drilling method can also effectively prevent the partial drilling hole.
How to remedy A, bending hole is not serious, can readjust the rig to continue to drill. In serious cases, the clay should be backfilled and then drilled after dense deposition. Do not use impact drill to repair the hole directly to avoid drilling. B. When the deviation is not serious and the hardness of the rock surface is not high, use the flat bottom drill bit for leveling and then drilling or use the smaller drill bit before drilling. C. When the deviation is serious and the rock surface hardness is high, the drilling pile is of the same grade of concrete immediately. When the concrete strength reaches more than 70%, the smaller drill lead hole will be expanded; D. When the deviation is serious and the groundwater water quantity is not large, manual holes can be used to correct the inclined rock surface.
Post time: Feb-08-2025