Drilling Construction Technology of Large Diameter Drainage Hole in Wutongzhuang Mine

Abstract:

The paper introduced the drilling construction technology of drainage holes in Wutongzhuang mine. The 2 holes were of great depth and large diameter in soft-hard alternant stratum, construction was difficult with diameter shrinking and slant borehole. Small-diameter drilling and post-reaming were adopted with reasonable drilling tool assembly, drilling mud and effective deviation preventing measures, and the drainage hole construction was successfully completed.

Key words:large diameter drainage hole; drilling; verticality; drilling tool assembly; well cementing