TP140V高强度套管磨损研究

Study on Wear of TP140V High Strength Casing

通过全尺寸磨损实验机实验,研究了TP140V高强度套管在油基、高性能、饱和盐水、有机盐4种钻井液条件下,其磨损性能和磨损机理的变化。结果发现:相同密度下,添加重晶石加重时,4种钻井液的磨损系数相差不大;同时添加重晶石和铁矿粉时,油基、高性能、饱和盐水钻井液的磨损系数略有上升,但变化不大,而有机盐钻井液的磨损系数则增大了2倍以上。由此可见铁矿粉含量的增加,对有机盐钻井液的磨损性能影响较大。对磨损套管进行电镜扫描分析发现:有机盐和饱和盐水钻井液的套管磨损机理均为磨粒磨损,但是饱和盐水钻井液下的套管表面发生了三体磨粒磨损,磨损表面有严重的剥落坑,这是由于饱和盐水中铁矿粉含量过多的缘故,因此对饱和盐水钻井液进行加重时,可适量增加重晶石的含量,减少铁矿粉的含量。

The wear state and wear mechanism of TP140 V high strength casing under the conditions of oil base, high performance, saturated brine and organic salt drilling fluids were studied by using full-scale wear tester. The results show that the wear coefficients of the four drilling fluids are almost the same when barite is added to the drilling fluids at the same density; when barite and iron ore powder are added at the same time, the wear coefficients of oil-based, high-performance and saturated brine drilling fluids increase slightly,while the wear coefficient of organic salt drilling fluid increases more than twice. It can be seen that the increase of iron ore powder content has great influence on the wear performance of organic salt drilling fluid. Scanning electron microscope analysis of worn casing shows that： the casing wear of organic salt and saturated salt drilling fluids is abrasive wear; however, three-body abrasive wear occurred on the casing surface under the saturated brine drilling fluid, and there were serious spalling pits on the wear surface, which was due to the excessive iron ore content in the saturated brine. Therefore, when the saturated brine drilling fluid is weighted, the barite content can be increased and the iron ore content can be reduced.