Cause Analysis And Treatment Of Drill Bit Slippage

Abstract:   Drill bit slip is one of the common problems in the application of water well drilling tools. How to deal with the dr...

  Drill bit slip is one of the common problems in the application of water well drilling tools. How to deal with the drill bit slip of water well drilling tools? The following is an analysis of the causes of water well drilling tools slippage and solutions.

  water well drilling tools drill bit slipping reasons:

  When using the friction rod to drill into the mud layer of the water well drilling tools, pay attention to the depth of each bucket. If the single bucket is too deep, the drill bucket is full of soil at this time, and there is nowhere to continue drilling into the cut soil. To accommodate, it will accumulate at the slag inlet of the drill bucket and in front of the bucket teeth. When the accumulated soil reaches a certain amount, the front of the bucket teeth can easily form a large piece of soil, which is equal to the height of the bucket teeth and forms a whole! At this time, the bucket teeth have lost the cutting effect. Under the lubrication of mud or water, the drill bucket cannot continue drilling. Therefore, when the bottom of the bucket is reversed and closed, there is no resistance at the bottom of the bucket at this time, so the bottom of the bucket will It is reversed with the drill bucket and cannot be closed. After the reversal, the main role is raised. When the water well drilling tools drill bucket is lifted in mud or water, the mud or water has a certain resistance, and this resistance will produce a downward force on the muck in the drill bucket. , Because the drill barrel of the drill bucket is tapered, the slag inside the drill bucket is not squeezed tightly due to the too fast rotary digging footage, and the main role is lifted too fast, which causes the slag in the bucket to fall out! Therefore, not every time the bottom of the bucket is not closed, the muck can fall out...At this time, the fallen muck has lost the original integrity of the solid soil, so after the second drilling, the tooth tip is directly inserted into the muck, and the bucket is drilled. The floor surface is directly pressed on the muck. As the drill bucket rotates and drills, the unevenness, and gaps of the falling muck are completely compacted. When the muck cannot be compressed, the plane of the floor is supported by the muck. The tooth rotates repeatedly in the groove that has already been drawn. At this time, three layers are formed. The first layer is the drill bucket that rotates repeatedly, and the second layer is the falling muck: the interlayer and the third layer is the uncut solid soil. Because the diameter of the drill bucket matches the hole diameter, the drill rod rotates. There is no resistance-no reaction force-no friction-no pressure, the bottom plate and the falling slag will slip under the lubrication of water or mud.

  Methods to prevent water well drilling tools from slipping:

  The slippage phenomenon can be overcome, first of all, combined with the depth of the single bucket on the display. Although the drilling resistance of the mud layer is small, as the muck inside the drill bucket increases, it will produce resistance to the slag inlet, so the drilling resistance is increased. The sound of the planetary reducer on the powerhead changes with the resistance, so listen to the sound of the powerhead It can judge the footage. When the drilling resistance increases, the rotation speed of the powerhead will also decrease. Therefore, the footage can also be judged by the rotation speed of the drill rod. If the geology does not change much, the drilling time and depth of each bucket should be kept within a certain range, and the depth of the single bucket in the mud layer should be within 0.5 to 0.6 meters. When the bottom of the bucket is reversed and closed, try to drill when there is load At this time, the bottom of the bucket has a certain resistance, to prevent the bottom of the bucket from reversing together with the drill barrel.

  Treatment measures for water well drilling tools drill bit slip:

  (1) Water well drilling tools can be handled even if the drill bit has slipped. After the second drilling, first, determine the thickness of the falling muck through the data on the display, and then look at the softness and hardness of the falling geology. There is a lot of soil falling, and it is hard clay. Then replace the drill bucket with a smaller diameter than the pile to solve the slip. Because there is a large gap between the small diameter drill bucket and the whole wall, the fallen soil is in the drill pipe. Under the action of the weight and pressure of the drill bucket, it is squeezed to the side through the gap between the drill bucket and the hole wall. The small diameter drill bucket can drill normally when it touches the solid soil. When the small drill bucket is lifted, it is squeezed to the side. The virtual soil falls into the small-diameter hole, and the residue that does not fall into the small hole is squeezed into the small hole by the large-diameter drill bucket after the second drilling so that the large-diameter drill bucket can be drilled normally.

  (2) If the falling slag is soft mud with good compressibility, there is no need to change the drill bucket, repeatedly manipulate the pressure and the powerhead to reverse and forward, because there is a gap between the powerhead and the drill rod, each section There is also a gap between the drill pipe and the drill pipe. Although the drilling is slipping at this time, the weight of the drill pipe and the drill bucket has resistance. When the force meets the weight of the drill pipe and the bucket itself, it can produce resistance, and when there is resistance, there is reaction force, and when there is reaction force, there is friction. At this time, the pressure can be instantly transmitted to the virtual soil in the interlayer to compress it. The lower sludge, let the sludge squeeze up from the gap between the drill bucket and the whole wall, and enter a part of the drill bucket, until the bucket teeth touch the solid soil and drill normally, remember the oil port pressure when the reverse rotation is positive. The pressure can be transmitted instantaneously before.