Analysis on reasons of drilling difficulty in soft and outburst coal seam
Abstract：Presented the concept of ＂hole cave＂ based on analysis of reasons of deep hole drilling difficulty,and analyzed the effect of drilling due to ＂hole cave＂ formation.On the basis of the analysis ＂hole cave＂ types and causes,established fluid slag discharge model in ＂hole cave＂,mathematical methods was used to analyze the relationship between drilling depth and ＂hole cave＂.The analysis shows that the borehole depth is independent of the power of drilling rigs,and is related to the occurrence location and volume of the ＂hole cave＂ in the case of fluid slag discharge.Put forward a new viewpoint of hydrodynamic and mechanical slag discharge in order to overcome and reduce the harm of hole caves,and invented ＂double power low-spiral drilling rod＂.
Keywords：soft coal seamoutburst coal seamhole cavedrilling rod
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)