金川矿区复杂地层钻探孔壁失稳机理与对策研究

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

金川矿区目前资源开采逐渐向深部转移,采用的主要探矿方式为在采矿巷道中布设中深钻孔,由于矿区地质条件复杂,常出现钻孔垮孔、造浆、地层涌水、破碎等情况,影响了勘察效率。为了解矿区复杂地层影响钻孔孔壁稳定性的原因,对从矿区采取的岩样进行理化分析、微观分析和力学性质分析,结果表明金川矿区钻孔孔壁失稳主要是因为钻探过程中遇强水敏性、强破碎、强涌水和高地应力地层。通过对矿区钻孔孔壁进行稳定性评价,从冲洗液技术和工程技术等方面制定了钻探技术对策,为矿区钻探施工提供了技术支撑。

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.