Analysis of mud layer slipping of the hottest rota

Analysis of mud layer slipping of rotary drilling rig

I. the bucket bottom is closed

when the rotary drilling rig uses the friction rod to drill the mud layer of the water inlet pile, it is necessary to pay attention to the footage depth of each bucket. If the footage of a single bucket is too deep, at this time, the drilling bucket is full of soil, continue to drill, and there is no place to contain the cut soil, so it is accumulated at the slag inlet of the drilling bucket and in front of the bucket teeth. When the accumulated soil reaches a certain amount, it is convenient to form a large piece of soil in front of the bucket teeth, It is equal to the height of the bucket teeth and forms a whole! At this time, the bucket teeth have lost their cutting function, and the drilling bucket cannot continue drilling under the lubrication of mud or water. Therefore, when the bucket bottom is reversed and closed, there is no resistance at the bucket bottom at this time, so the bucket bottom will reverse with the drilling bucket and cannot be closed

II. Muck falling out

after reversing, the main reel will be lifted. When the drill bucket is lifted in mud or water, due to certain resistance of mud or water, this resistance will produce a downward force on the muck in the drill bucket. Because the drill barrel of the drill bucket is conical, the rotary drilling footage is too fast, resulting in the muck in the drill bucket being squeezed not dense enough, and the main reel is lifted too fast, resulting in the muck falling out of the bucket! Therefore, not every time the bucket bottom is not closed, the muck can fall out...

III. slip phenomenon

at this time, the muck falling has lost the original integrity of the solid soil, so after the second trip, the tooth tip is directly inserted into the muck, and the bottom plate surface of the drill bucket is directly pressed on the muck. As the drill bucket rotates, the falling muck is uneven and the gap is fully compacted. When the muck cannot be compressed, the plane of the bottom plate is held by the muck, The bucket teeth rotate repeatedly in the grooves that have already been drawn. At this time, three layers are formed. The first layer is the repeatedly rotating drill bucket, the second layer is the falling slag, that is, the interlayer, and the third layer is the uncut solid soil. Because the drill bucket is consistent with the diameter of the hole, the drill pipe rotation has no resistance → no reaction force → no friction → no pressure, and the bottom plate and the falling slag slip under the lubrication of water or mud

IV. prevention of slip

slip can be overcome. First, combined with the footage depth of a single bucket on the display. Although the drilling resistance of the mud layer is small, with the increase of the slag in the drill bucket, there will be resistance to the slag inlet. Therefore, when the drilling resistance is increased, the sound of the planetary reducer on the power head changes with the resistance, so listening to the sound of the power head can judge the footage. When the drilling resistance increases, the speed of the power head also decreases, Therefore, according to the new vehicle plastic plan blueprint released by the plastics branch of the American Chemical Council (ACC), the rotation speed can also judge the footage. If the geological change is small, the drilling time and depth of each bucket should be kept within a certain range, and the footage depth of a single bucket in the mud layer should be within 0.5 to 0.6 meters. When reversing and closing the bucket bottom, try to have a certain resistance at the bucket bottom when the drilling is loaded, so as to prevent the bucket bottom and the drill barrel from reversing together

v. slip treatment

[1] even if there is a slip phenomenon, it can be handled. After the second trip, first determine the thickness of the fallen muck through the data on the display Qee tech new thermoplastic composite pre molding technology, and then look at the soft hardness of the fallen geology. If there is a lot of soil falling, and it is hard mastic, then change a 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 hole wall, the fallen soil is squeezed to the side through the gap between the drill bucket and the hole wall under the weight of the drill pipe drill bucket and the pressure. The small-diameter drill bucket can normally drill when it contacts the solid soil. When the small-diameter drill bucket is lifted, the virtual soil squeezed to the side falls into the small-diameter hole, and the muck that does not fall into the small hole is squeezed into the small hole by the large-diameter drill bucket after the second trip, Thus, the large diameter drill bucket can drill normally

[2] if the fallen muck is soft mud and has good compressibility, there is no need to change the drill bucket, repeatedly operate the pressurization and reverse the forward rotation of the power head. Because there is a gap between the power head and the drill pipe of the wood-based panel universal testing machine, and there is also a gap between each drill pipe and the drill pipe. Although the drilling slips at this time, the weight of the drill pipe and the drill bucket itself has resistance, so quickly reverse the forward rotation drill pipe and use the gap to produce impact force, When the impact force meets the weight of the drill pipe bucket itself, it can produce resistance. With resistance, there is reaction, and with reaction, there is friction. At this time, the pressure can be instantly transmitted to the virtual soil of the interlayer to compress the fallen muck, so that the muck can be squeezed up from the gap between the bucket and the hole wall, and enter a part of the bucket until the bucket teeth contact the solid soil for normal drilling. Be sure to remember when reversing the forward rotation, The pressure can be applied before pressurization. 5. The experimental steps can be transferred instantly