Construction technology and development tendency of gas drainage borehole in soft and outburst seam

With an analysis on a study and application status of a gas drainage borehole construction technology in a soft and outburst seam,based on the different drilling method,borehole protection method and reconstruction method,the paper introduced the development course of the borehole construction technology in the soft and outburst seam,analyzed the meaning,advantage and disadvantage,application scope and promoted application status of each technology and pointed out a directional drilling difficulty in seam,a small diameter of the screen pipe protected borehole,a small reconstruction scope of the borehole production increased and other problems existed in the available borehole construction technology. Meanwhile,the paper provided the future development tendency of the gas drainage borehole construction technology in the soft and outburst seam,including the drilling mud pulse with the drilling measuring and directional drilling technology,the electromagnetic waves with the drilling measuring air directional drilling technology,the large diameter screen pipe with the borehole drilling technology and the large diameter and the reconstruction technology of the small curvature sidetrack drilling as well as other orientations.