Analysis on Drilling Technology of Large Diameter Gas Drainage Well

LIU Zhi-qiang; JING Guo-ye; WANG Hua

doi:10.3969/j.issn.1002-6029.2015.01.001

Abstract：Gas drawing underground produces a very important function to a coal mine safety produc‐tion ,pumping out gas must be put together and then transported to the ground ,in order to be com‐prehensively used.Constructing an independent gas drainage well leading to the ground has obvious advantages compared with the traditional way of mine shaft pipelines arrangement. Because the diame‐ter of gas drainage well is much larger than the diameter of geological prospecting borehole ,and much smaller than the diameter of coal mine shaft ,its construction must use boring machine only.This pa‐per summarized the function and structure of gas drainage well , and divided it into two types , i.e.centralized gas drainage well and pipeline gas drainage well.The centralized gas drainage well can be constructed by ordinary sinking method ,full face shaft boring machine ,raise boring machine ,etc;the pipeline gas drainage well was generally constructed by mechanical drilling method ,the key to the drilling technology includes efficient slag removal ,pipeline installation and fixing.This paper com‐pared the application scope ,advantages and disadvantages of different drilling technologies (including geological drilling rig ,petroleum drilling rig ,down-the-hole drilling rig ,shaft drilling machine and raise boring machine ,etc.) and slag removal styles(including positive cycle slag removal ,reverse cir‐culation slag removal ,free fall slag removal ,etc.) ,and expounded the technology of pipeline installa‐tion in drilling mud or in bare borehole.This paper also pointed out the advantages of raise boring ma‐chine drilling gas drainage wells and its technical process contents which remain to be deeply studied.