大倾角地层煤层气钻井
CBM well boring in strata at great inclination
煤层底板
coal seam floor
seam floor
thill
coal seam floor rock mass
coal seat
coal floor
floor of coal seam
seamfloor
煤层底板突水
water inrush from coal seam floor
煤层底板注浆改造技术
grouting techniques on coal floor
煤层煤质
coal seam a nd coal quality