Research and Application of Drilling Bit for Deep Air DTH Hammer Drilling Technology

Abstract

Air DTH hammer drilling technology for shallow Wells has been very mature and the specifications and models of supporting bit product are also very complete and comprehensive. Drilling deep Wells, however, presents a number of special problems to solve. This paper first introduces the problems of common DTH drill bit in deep drilling, including the broken up of the hammer handle, the reasonable bit size cannot be guaranteed due to easy diameter reduction and the high proportion of tripping time due to short longevity of single bit. Then the authors, collaborating with a domestic DTH manufacturer, The borehole shrinkage problem has been solved in the drilling of air DTH hammer drilling after nearly ten years of continuous research, development, practice and improvement; The drilling life of single drill bit can be up to 800 meters by adopting polycrystalline diamond compact.By constantly adjusting and improving the material and heat treatment process of the bit body, the footage life of the bit body can be greatly extended and the failure rate of drilling can be reduced. The results of this paper will lay a solid foundation for the popularization of air DTH hammer drilling technology in deep Wells.