Application of screen tube hole protection technology in drainage engineering of weakly cemented sand mudstone interactive formation

Abstract

The pre-drainage of roof water in working face is one of the main means of water disaster prevention and control in coal mines in western China. Affected by the widely developed weakly cemented sand mudstone interactive stratum, the drainage drilling hole is easy to collapse and shrink, blocking the drainage channel, resulting in the rapid attenuation of the water inflow in a short time. The problem of hole collapse can be effectively solved by installing a steel screen tube with a total length longer than the depth of the unstable layer in the drilling. The attenuation rate of drilling water inflow and the total amount of drainage are used as the evaluation indexes of drainage effect. After installing the screen, the drainage efficiency of drilling for 30 days is increased by 49.3% compared with that before installation, and the drainage water in the drilling is increased by 10 times in the same time period.

Keywords

• weakly cemented sand mudstone interactive formation
• roof water drainage
• drilling instability
• screen tube structure
• screen tube installation process