Research on mechanism and countermeasure of borehole wall destabilization in complex formation of Jinchuan mining area

Abstract:

At present， the resource exploitation in Jinchuan mining area is gradually going to the deep part， and laying medium-deep boreholes in the mining roadways is the main exploration method. Complex geological conditions such as borehole collapse， slurry making， water inrush and strata breaking often occur， which greatly affect the exploration efficiency. In order to find the reasons why the complex strata in the mining area affect the stability of borehole walls， physical and chemical analysis， micro and mechenical analysis of the rock samples taken from the mining area are made. The results show that the strata encountered with strong water-sensitive， highly fractured， strong water inrush and high geostress during drilling is the main reason which affect the borehole wall destabilization in Jinchuan mining area. Through the stability evaluation of borehole wall in the mine area， drilling countermeasures for complex strata were made from the perspectives of flushing fluid technology and engineering technology， which provides technical support for drilling work of the mine area.

Key words:complex strata;strong water sensitivity;highly breaking;strong water inrush;high geostress;destabilization of hole wall;flushing fluid technology;Jinchuan mining area