Successfully solve the problem of backflow sticking in the new drilling well

In the middle shift of August 20, the sticking problem of the raise boring of the stope return air shaft constructed by Xinqiao project department was successfully solved, and the construction returned to normal. It is reported that on the evening shift of August 11, the drilling tools of the project department were suddenly completely stuck in the reverse pulling process of the air return shaft in the - 320m middle section of the stope, and the company attached great importance to it. The project department and the mechanized engineering branch quickly organized personnel to inspect the site, and determined that the reason for the sticking might be due to the stable block falling and stuck in the karst cave of the wall during the brush expansion process. A variety of solutions were tried on site: first, the drilling rig was impacted with pressure, and then a small amount of explosive was put down from the upper hole to break the drill pipe of the raise boring tool and lift it up, but the cutterhead was still stuck. After blasting, the raise boring tool was successfully lowered to - 372m level stope, but the problem has not been solved. The two drill pipes that were broken in advance were left in the hole and completely blocked, and the drill pipe still could not be pressed down to conduct the hole by applying pressure from the upper part. The project department decided to send the explosive from - 372m level to the drill pipe position on the premise of ensuring safety, use the blasting vibration to loosen the surrounding rock at the drill pipe stuck position from below, then apply pressure from above, and finally successfully conduct the hole. (Zhu Chuanxiang)