大直径定向长钻孔用ф73mm钻杆接头设计及应用

Joint Design and Application of ф73 mm Drill Rod for Large Diameter and Directional Long Borehole Construction

针对煤矿井下大直径定向长钻孔施工时常规钻杆频繁发生断裂及粘扣等问题,分析了钻杆失效原因,通过优选接头材质并借鉴石油管接头的设计经验,开发出双顶结构接头及W-038R螺纹牙型,并利用有限元分析软件、室内试验及现场试验的方式依次对设计开发的W-038R螺纹接头和常规V-040螺纹接头进行对比,结果表明,工况加载条件下W-038R螺纹接头应力分布要明显优于V-040螺纹接头,前者可以满足使用要求,而后者会发生联接失效;室内静扭试验表明,设计的W-038R螺纹接头静扭能力可达22 000 Nm,是V-040螺纹接头1.5倍;现场试验表明,同等施工条件下,W-038R螺纹接头钻杆千米扩孔进尺钻具事故率约为V-040螺纹接头常规外平钻杆的18%。

According to the failure such as fracture,fastening is easy to appear while drilling large diameter and directional long borehole using conventional pipe, a premium thread with double shoulder which called W-038R is designed by optimizing joint material and taking example by oil pipeline joint design experience. This paper contrasts W-038R joint with V-040 joint through FEA, laboratory test and field test. FEA results show that W-038 R joint stress distribution is significantly superior to V- 040 joint,the former can satisfy the use requirement, while the latter connection failure happens; Laboratory tests turn out that W-O38R joint static torsion capacity is 1.5 times V-040 joint; Field tests show that the drilling pipe accident rate of W-038R joint is about 0.26/km while drilling large diameter and directional borehole, about 18% of V-040 joint under same drilling condition.