定向钻硬岩正扩工艺钻杆刺漏原因分析及应对措施

Discussion on causes and countermeasures of drilling pipe leaking in hard rock forward reaming process of directional drilling

对于某些施工场地狭窄区域,只能采用正扩工艺实施定向钻扩孔作业。由于正扩工艺是正向推着钻具向前扩孔,在硬岩地层施工中钻具和钻杆承受推力大,加之孔洞直径远远大于钻杆直径,造成施工中频繁出现钻具磨损、钻杆断裂等情况。结合工程实例,在简要介绍工程概况的基础上,较为详细论述了采用无损检测等手段,对施工中钻杆出现的刺漏、断裂现象进行分析,以及通过采取调整钻杆规格型号、选用适合动力钻具、选配新型液力推进器等措施,减小了直接作用于钻杆的推力和扭矩,降低了钻杆疲劳的机率,取得良好效果。

In some narrow construction sites,directional drilling has to apply the forward reaming process.In hard rock strata,the drill tool wear and drill pipe fracture occur frequently during construction because the drill tool and drill pipe bear high thrust,and the hole diameter is much bigger than the dill pipe diameter.Combined with engineering example,this paper describes the NDT detection means,analyzes the drill pipe leaking and fracture phenomena,and puts forward the countermeasures such as adjusting the drill pipe specifications,choosing suitable power drill tool and using new hydraulic thruster.As a result,the thrust and toque acting on the drill pipes are reduced,leading to fatigue probability decrease.