Kilometer directional drilling: Simultaneous extraction of coal and gas from a high gas coal seam
Abstract：A new method of gas drainage using kilometer scale directional drilling in the roof crack area is described. The German DDR-1200 directional drill was used to prepare the holes. A system for drilling and simultaneous coal and gas extraction was built. A large amount of lateral and vertical fracturing in the overlying strata of the working face was observed. The height of the fractured zone is about 34 meters and the maximum separation is roughly 240 mm beneath the main key stratum, which in turn is 22 m away from the roof. An enriched gas area forms in this region. The fracture zones develop in a range from 0 to 60 meters from the mining gateway to the goal. A field test was carried out at the 14301 working face. A drilled hole was located 22 m above the 14301 working face roof and 15 m from the haulage roadway, in an in- clined direction. The extraction concentration was more than 70% over an extraction time of more than 120 days. A remarkable drainage effect was achieved while simultaneous extraction of coal and gas was realized.
Keywords：simultaneous extraction of coal and gashigh gas coal seamfracture ~ gas enrichmentzonekilometer and direction drill
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 885-892 )