Multiple step type drilling and protecting integrated system and process for soft coal seam

Abstract

The invention discloses a multiple step type drilling and protecting integrated system and a process for a soft coal seam. The system mainly comprises an air compressor, a high-pressure rubber hose, a hole protecting drilling machine, a rack, a hole protecting drilling rod, a guider and a simple drill. The process comprises the steps of firstly drilling a hole by using a common drilling rod and a common drill and pulling the common drilling rod and the common drill out of the hole after the hole is formed; then performing second drilling of the formed drill hole by using the hole protecting drilling rod and the simple drill in a matching mode, and simultaneously performing wind-power auxiliary slagging, when an end hole point is drilled, the hole protecting drilling rod is not withdrawn, the whole body is left inside the hole, and hole wall supporting and gas extraction functions are achieved; and finally pulling out and recycling the hole protecting drilling rod through the hole protecting driller after the gas extraction is completed. According to the system and the process, the process is unique, a hole protecting pipe can transmit high-pressure air and can extract gas, the coal dust discharging performance is strong, the hole protecting pipe moves forwards along the drill hole easily, the hole protecting pipe diameter is large, the hole protecting length is long, the problems that the soft coal seam is small in hole protecting pipe diameter and short in feeding distance are solved, and the system and the process are particularly suitable for soft high gas coal seams with a value of a sturdiness coefficient f, which ranges between 0.3 and 0.8.

Description

technical field [0001] The invention relates to a coal seam drilling and protection system and technology, in particular to a soft coal seam step-by-step integrated drilling and protection system and technology. Background technique [0002] The proportion of soft coal seams in my country's coal seams is relatively large, the coal quality of soft coal seams is soft, the permeability is poor, and the gas content and gas pressure are often relatively high. This type of coal seam cannot solve the problem of large gas gushing during coal mining simply by relying on mine ventilation. Perform gas extraction. At present, the drilling depth of bedding gas drainage in my country has generally reached more than 100 meters, but the firmness coefficient f The soft coal seams with a value between 0.3 and 0.8 have poor coal stability, and are prone to deformation and local collapse after gas drainage boreholes are drilled, resulting in reduced gas drainage efficiency. [0003] The patent...

AI Technical Summary

Problems solved by technology

At present, the drilling depth of bedding gas drainage in my country has generally reached more than 100 meters, but the firmness coefficient f The soft coal seam with a value between 0.3 and 0.8 has poor coal stability, and the gas drainage borehole is easy to deform and partially collapse after drilling, resulting in a decrease in gas drainage efficiency

[0003] The patent No. CN101446178A discloses a wind pressure air drilling process in the soft and outburst coal seam in the well. Strict requirements on the upper limit of the borehole diameter lead to a small diameter of the borehole protection pipe, so there will be a large space between the borehole protection pipe and the borehole wall, which cannot effectively resist the collapse of the borehole, and the effect of borehole protection is not ideal; the paper "Gas Pumping Discussion on Drilling Hole Protection Technology” proposed the guide pulley to send the protection hole pipe technology, but the maximum feeding length of the protection hole pipe is only more than 70 meters, which cannot meet the requirements of the length of the drainage hole protection hole

And in the extremely soft coal seam, the gas drainage hole will partially collapse within a short time after the drilling, in this case, the process cannot send the hole protection pipe into the borehole

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