套管磨损三维表面形貌恢复及其机理分析

在DCWT-1000型套管摩擦磨损试验机上进行了套管摩擦磨损试验,研究深井、超深井中"冲击-滑动"复合磨损对套管磨损行为的影响,采用三维表面形貌测试仪、光学显微镜及扫描电子显微镜观察分析了在不同载荷条件下套管磨损表面的微观结构和表面形貌,在此基础上对套管磨损表面进行了三维恢复并计算套管磨损表面的主要形貌参数,探讨了套管磨损表面的磨损机理.结果表明:套管的磨损性能与载荷有关;在不同载荷条件下,套管磨损表面的三维形貌具有不同特点,且主要的表面形貌参数与载荷呈现出较好的相关性,证明了三维形貌分析方法能够真实反映套管磨损表面的情况;当冲击载荷和频率不大时,套管的磨损机制以磨粒磨损为主,兼有粘着磨损,随着冲击载荷和频率增加,套管磨损表面出现明显粘着剥落和疲劳剥落迹象,并出现疲劳裂纹扩展和连通,套管的磨损机制向粘着磨损和疲劳磨损转化,磨损趋向严重.

3D Surface Topography Rebuilding and Analysis of Casing Wear

Casing wear was investigated on the DCWT-1000 casing wear tester, the influence of impact -slide of deep and ultra-deep well on the wear behavior of casing was studied. Microstructure and surface topography of the wear surface of casing under different loads were investigated by means of 3 D surface topography measurement apparatus, microscope, and SEM. 3D topography of wear surface of casing was rebuilt and the main topography parameters were calculated, and the wear mechanism of casing was discussed. It is found that the load intimately correlated with wear property and surface topography parameters of wear surface of casing. 3 D topographies of wear surface of casing were different under different loads, there was better correlation between the main topography parameters and the load, and it is proved that the 3 D topography analysis can more truly reflect the casing wear. The abrasive wear mainly occured under small load, and sometimes the adhesive wear appeared too, peeling due to adhesive wear and fatigue wear was seen obviously, and the fatigue crack appearred development and join, the casing wear mechanism changed to surface fatigue and adhesive wear, the casing wear becomes more serious.