Construction method of pipe drilling:

　　With pipe drilling, the pneumatic DTH hammer is changed to an eccentric drill, and casing and casing shoes are added. Pipeline drilling construction technology requires high requirements for drilling rigs, and the equipment needs to be equipped with various drilling tools, which not only greatly affects the efficiency of hole formation, but also prone to drilling accidents.

　　Issues that should be paid attention to during construction

　　(1) During the drilling process, due to the downward deviation of the drilling tool under the action of gravity, the drilling opportunity will be tilted. The longer the drilling, the more obvious this phenomenon. Therefore, the inclination angle of drilling in place should be less than the design inclination angle.

　　(2) Before the construction of the eccentric heel pipe drilling tool, check the impactor, eccentric hammer, centralizer, casing shoes and pneumatic DTH hammer one by one to make them work normally. The eccentric hammer should be able to rotate flexibly, the connecting pin and locking mechanism should be firm, the connection between the drill rod and the DTH hammer and the eccentric drill should be reliable, and the casing and casing shoes should not have cracks.

　　(3) When drilling with a drill pipe, make sure that the drill bit is in contact with the gravel soil layer, then turn the head first, and then turn on the wind for pulse drilling.

　　(4) The hole powder should be blown by strong wind every 0.3 m ~ 0.5 m to keep the hole clean. When blowing holes, the lifting distance of the center drill should be strictly controlled; during the drilling process, it is forbidden to pull up the center drill or reverse the drill rod back and forth.

　　(5) When the eccentric rotating part is stuck by the slag and cannot collapse, the air compressor should be started to clean the borehole again, the DTH hammer should work for a short time, and then try to lift again, and so on, until the center drilling tool is raised .

　　(6) The length of the follow pipe can be determined according to the actual geological conditions. When the downcomer does not need to be in place and the depth of the downcomer reaches the required depth, conventional drill bits can be used for open hole drilling.

　　(7) After the cable is laid successfully, the casing can be pulled out. When pulling out the casing, first install the base of the pipe extractor on the surface of the pull-out base, then install and fix the cylinder on the base symmetrically from left to right or top to bottom, and then install the top plate and casing slips, and the installation is complete Then start the oil pump cylinder to inject oil and pull out the casing using the principle of hydraulic force transmission. When installing the oil cylinder, the extension direction of the oil cylinder should be consistent with the axial direction of the shell to prevent the shell from breaking due to asymmetrical force.