127mm G105钻杆管体刺穿失效分析

通过力学性能测试、金相显微组织和断口分析,并结合钻杆的受力状态,对某127mm G105钻杆管体刺穿失效原因进行分析。结果表明,钻杆刺穿失效的原因是由于操作不当,大钳夹持管体时产生许多深的牙痕,钻井过程中,牙痕底部由于应力集中形成裂纹,在交变应力作用下,裂纹疲劳扩展,最终导致钻杆形成刺孔。

Analyses on the Piercing Failure of 127mm G105 Drilling Pipe

The reason on the piercing failure of 127mm G105 drilling pipe was analyzed based on the test of mechanical properties,analysis of metallographic micrograph and fracture,and the force status of drilling pipe.Results show that the main reason for piercing failure of drilling pipe is the improper operation of drilling workers while holding the pipe by the clamp,which caused lots of deep clamp prints on the outside of drilling pipe.During the drilling process,cracks developed from the prints and extended quickly under the effect of alternating stresses.In the end,they leaded to the pierced hole on the drilling pipes.