Original title: What kind of formations are different rotary drilling bits suitable for? Barrel drill, spiral drill bit and bailing bucket are commonly used in the construction of rotary drilling rig, so what kind of strata are they suitable for? Duff Equipment has sorted out the formation adaptation of some rotary drilling bits and shared them with you. I hope it will be helpful to your rotary drilling construction. Barrel drill At present, there are two kinds of common core barrel drills: cutter barrel drill (suitable for medium hard bedrock and gravel) and roller barrel drill (suitable for hard bedrock and large boulders). In the two types of barrel coring drill, there are two types of bit with coring device and without coring device, which mainly depends on the difficulty of coring. Because the cone coring bit is mainly used for hard rock drilling, and the annular area of drilling is large, if conditions permit, reverse circulation drilling can be added to the bit part to improve the drilling efficiency. In the soil layer with high compactness or some soft rock layers, when the friction drill pipe is selected to cause slippage, the barrel drill can be used to deal with it. Duff auger bit Rock-socketed auger bit It is suitable for the crushing of boulders, boulders and hard rock strata in the hole. For some clay strata and moderately dense pebble soil, when the double-bottom bailing bucket of the selected soil layer cannot be used for drilling, the auger bit can be used for drilling. Double-bottom bailing drill bucket for soil layer It is suitable for silt, fine sand, silt, silty clay, clay, some soil-like soft rocks, Tapered Rock Bit , such as fully and strongly weathered mudstone, moderately weathered mudstone, argillaceous sandstone, etc., as well as hard rocks with high degree of weathering, such as fully and strongly weathered granite, etc. It is the most widely used bit in the industry. Duff pick double bottom bucket Pick double-bottom bailing bucket It is suitable for pebble, gravel layer, moderately weathered soil-like soft rock, such as moderately weathered argillaceous sandstone, argillaceous conglomerate, etc. When drilling hard rock, it is often used with barrel drill and spiral drill bit. It is difficult to drill hard bedrock, large boulders and hard permafrost directly with auger bit or rotary drill bit, so it is necessary to drill with barrel ring bit, auger bit and bailing bit. It can be divided into coring annular barrel bit and non-coring annular barrel bit. According to the different strata drilled, it can be divided into pick ring bit for weathered bedrock and permafrost drilling and cone ring barrel bit for hard bedrock drilling. The structural characteristics and principle of the annular barrel type coring bit: the bucket body is divided into two layers of an inner tube and an outer tube, the outer tube is welded with main cutting teeth, the inner tube is welded with auxiliary cutting teeth, and the lower end of the inner tube is provided with a hinge blade for supporting a core. The drill bit and drilling tool shall be selected according to the function configuration of the rotary drilling rig. If the rotary drilling rig has the function of forming the trench of the underground continuous wall, the hydraulic grab bucket or double-wheel milling machine can be selected to form the trench of the continuous wall. If the auxiliary winch has the function of automatic rope release, the percussive drill bit and the percussive grab drill bit can be selected to drill large-diameter pebbles or boulders. Gas-liquid drilling can be carried out if equipped with air chamber and swivel. If it is equipped with double power head or pipe rolling machine,mining dth bit, it can be used for casing drilling, which is a very effective method for smoothly passing through quicksand, breaking gravel and silt layers during drilling. Return to Sohu to see more Responsible Editor:. wt-dthtools.com