Xi’an Research Institute，China Coal Technology and Engineering Group Corporation，Xi’an ,China

为解决煤矿井下大直径定向长钻孔扩孔时钻杆易发生接头断裂的问题,通过改进接头结构,优选螺纹牙型,试验新材料及其热处理工艺,研制出Ф89 mm高强高韧钻杆。介绍了钻杆设计和关键加工技术,在顾桥矿进行现场试验,共施工7个钻孔,Ф153 mm孔径扩孔总进尺2 309.5 m,最大单孔扩孔深度530 m;Ф220 mm孔径扩孔总进尺651 m,最大单孔扩孔深度506 m;Ф248 mm孔径扩孔总进尺208 m,最大单孔扩孔深度158 m。试验结果表明,该钻杆在煤层顶板高位大直径定向长钻孔施工时具有较好的推广应用价值。最后,针对现场施工时存在的问题给出了相应建议。

For solving drill rod joint fracture frequently while drilling large diameter and long directional borehole，ø89mm drill rod with high strength and high toughness is developed after improving joint structure，optimizing thread type，testing new material and its matched heat treatment process.The paper introduced design scheme and key control point on processing techniques of drill rod briefly.In field trial of Guqiao Coal Mine，it drills 7 boreholes.When reams holes to ø153 mm,it drills 2 309.5 m in total of which the maximum drilling depth of single hole is 530 m; when reams holes to ø220 mm，it drills 651 m in total of which the maximum drilling depth of single hole is 506 m; when reams holes to ø248 mm,it drills 208 m in total of which the maximum drilling depth of single hole is 158 m.It shows the drill rod has good value for popularization and application in large diameter and directional long borehole construction at roof high-level of coal layer.Finally，it provides corresponding proposal for open questions of reaming construction.

中国煤炭科工集团西安研究院有限公司科技创新基金资助项目(2016XAYMS04)；