摘要
某井在钻井作业时产生卡钻,在解卡操作过程中发生了127 mm×9.19 mm G105钻杆的断裂失效事故。通过对失效钻杆断口的宏观形貌分析、钻杆材质的一系列理化性能检测,以及钻井作业操作过程的综合分析,得出了钻杆失效的原因为解卡过程中钻杆接头与井壁岩石或沉砂发生摩擦磨损,产生的摩擦热达到了钻杆接头材料的相变温度,钻杆在井下发生了“二次热处理”,从而降低了材料的强度和性能。同时,摩擦磨损导致了钻杆有效截面的不断减少,当有效截面处的拉伸应力超过材料屈服强度时,钻杆发生塑性断裂失效。提高井壁的稳定性、增加短程起下钻频次、保持泥浆循环通道畅通,是解决此类钻具失效的有效手段。
During the drilling operation of a well,a 127 mm×9.19 mm G105 drill pipe was fractured in the process of releasing stuck.Through macroscopic morphology analysis of the fracture surface,and physical and chemical property tests of the failed drill pipe,as well as the analysis of the sticking factors in the drilling operation,it is concluded that the failure of the drill pipe is friction and wear between the drill pipe joint and the necked borehole wall rock or grit in the process of releasing the sticking.The generated friction heat reaches the phase change temperature of the drill pipe joint material,as a result,the drill pipe occurs“secondary heat treatment”underground,which reduces the properties of the drill pipe material.At the same time,friction and wear lead to the decrease of the effective cross section area of the drill pipe.As a result,yield fracture occurs under tensile load.It is suggested that improving the stability of wellbore,short trip and keeping the mud circulation channel unblocked are effective methods to prevent drilling tool failure.
作者
李沛轩
LI Peixuan(CNPC CCDC Changqing General Drilling Company,Xi'an,Shaanxi 710018,China)
出处
《石油管材与仪器》
2021年第4期46-48,54,共4页
Petroleum Tubular Goods & Instruments
关键词
钻杆
断裂失效
卡钻
井壁稳定
drill pipe
fracture failures
sticking
stability of borehole wall
