内涂层质量对钻杆失效影响的试验研究

Experimental Study on Influences of Internal Coating Quality on Drill Pipe Failure

内涂层技术是一种预防钻杆提前失效和提高钻杆使用寿命的重要措施,随着钻井深度增加、钻井温度压力增高等,时常会发生钻杆内涂层失效剥离和钻杆腐蚀刺漏断裂。通过分析一起钻杆内涂层脱落腐蚀导致的钻杆刺漏案例,探讨了钻杆刺漏失效的原因;并针对川渝地区常用的两种钻杆内涂层,分析了钻杆内涂层表面平整度、漏点、粗糙度、附着力、耐磨性、耐高温高压性和耐酸性等对钻杆失效的影响,还提出了内涂层现场使用的建议。

Internal coating technology is an important measure to prevent drill pipe from premature failure and improve its service life.However,with the deepening of drilling depth and the increase of temperature and pressure,the failure and peeling of internal coating as well as corrosion and leakage of drill pipe often occur.Failure reason was analyzed through a case of leakage caused by internal coating falling off and corrosion.Furthermore,the influences of surface flatness,leakage point,roughness,adhesion,wear resistance,high temperature and high pressure resistance as well as acid resistance of inner coating on drill pipe failure was discussed by two kinds of internal coating commonly used in Sichuan and Chongqing area.Then,suggestions for its on-site application were put forward.