Jiangxi Ruijing Tool Technology Co., Ltd.
Mobile phone: Mr. Lin 13755712999
Address: The Hardware Tools Industry Park of Wenzhou Merchants,High-technology development zone,Xinyu city,Jiangxi Province
Borehole drilling is generally described by four characteristics: straight longitude, depth, straightness and stability.
1. Hole diameter
The diameter of a borehole depends on the purpose for which it is used. There are many factors affecting the selection of blasting holes in drilling operations. For example: the size of rock particles required after rock breaking; the type of blasting chosen; the requirement of "quality" of rock particles blasted (the ratio of smoothness and breakage of particle surface); the allowable degree of surface vibration in blasting operation, etc. In larger quarries or large open pits, the cost of drilling and blasting per ton of rock is often reduced by using large-bore blasting operations. In underground rock drilling, mining equipment is limited by underground space. In the drilling operation of water well, the size of rock hole depends on the diameter of pipe or the diameter of matching equipment required by pump. In the aspect of rock support hole, the diameter of different bolts is the decisive factor.
2. Depth of hole
The depth of the hole is affected by drilling equipment. In limited space, only short brazing tools can be selected. Short drilling tools with threaded joints are necessary for drilling holes in limited space. In the drilling of blasting holes (horizontal or vertical holes), the drilling depth is slightly deeper than the theoretical depth or terrace height. Under some rock drilling conditions, the drilling depth is required to be deeper (50-70 meters or deeper). In general, DTH drilling method is used instead of anvil percussion drilling method. The energy transfer of DTH drilling method and the effect of powder discharge under deep hole conditions are more efficient.
3. Hole straightness
Hole straightness is a variable factor with rock type and natural conditions, selected mining methods and selected mining equipment. In horizontal and inclined drilling, the weight of the brazing tool also affects the deviation of the hole. When drilling deep blasting holes, the drilled holes must be as straight as possible in order to accurately obtain the ideal blasting effect by charging.
In some types of drilling operations, deep holes are often drilled, and the straightness of holes is very high, such as pipe holes or cable holes. Even the requirements for wellbore are very strict so that water pipes and pumps can be installed smoothly.
The straightness of holes can be improved by using different types of guiding equipment, such as guiding bit, guiding drill pipe and guiding drill pipe. In addition to the deviation of the borehole itself, the direction of the borehole is also affected by factors such as the adjustment degree of the advancing beam and the accuracy of the opening. Therefore, in this regard, considerable accuracy is required. The results show that about 50% of the hole migration is caused by unreasonable advance beam adjustment and poor opening.
4. Hole stability
Another requirement for drilling holes is to remain stable until they have been charged or used for other purposes. Under certain conditions, for example, when drilling loose materials or soft rock zones (where there is a tendency of debonding and blocking rock holes), it is very important to use drilling pipes or rubber pipes to go down along the drilled rock holes.