Application and development of directional drilling technology in strata grouting transformation for coal mines in China

WANG Hua

doi:10.11799/ce201709001

Abstract：Firstly, the author introduces the two main forms of directional drilling grouting in coal mines of China, namely s-shaped small displacement directional borehole used in pre-grouting for vertical shaft and L-shaped extended-reach directional borehole used in grouting transformation for large area formation( including the conventional horizontal directional drilling grouting from ground surface, the horizontal directional drilling grouting from ground surface in which part of existing geological borehole is used, the horizontal directional drilling grouting in underground roadways), the depth of pre-grouting for vertical shaft by s-shaped directional borehole and the horizontal displacement length of ground directional borehole for grouting deep strata have all exceeded 1000m;secondly, the author points out that directional drilling grouting technology is faced with a lot of questions, such as grouting theory, process and equipment, inspection and evaluation of the grouting effect, and so on, with the continuous development of coal mining to the deep extension and the scale of a single face continues to increase;thirdly, the author indicates that researchers should strengthen the research on simulation test system for grouting rock under flowing water conditions and grouting simulation test, detection method on grouting effect of deep strata and spread regularity of grout( especially, grouting by horizontal drilling method) , detection on grouting effect, find out the main influencing factors of grout diffusion in deep strata, so the law of grout diffusion can be revealed.