Drilling problem and countermeasures of drilling technology in Guxu Mining Area of South Sichuan Coalfield

The geological conditions of Guxu Mining Area in Southern Sichuan Coal Field are complicated, such as thick coal measure strata, loose coal seam, fissure development of karst cave, pore wall instability and collapse, hole leakage and low coal seam taking rate exist in the drilling process.Considering the geological conditions, the drilling structure design and coal bit selection are optimized.According to the characteristics of coal measure strata, the polymeric anti-collapsing washing fluid is used to drill to prevent mudstone hydration expansion and keep the hole wall stable.According to the different types of leakage in the drilling process, the porous leakage is blocked, the fissure leakage is blocked by bridging plugging slurry, and the karst cave leakage is blocked by polyacrylamide cement slurry.The above technical countermeasures are tested in ZK3003 hole of the mining area, and good production results are obtained.It has a good guiding and reference role for drilling construction in the mining area.