钻井工况下钛合金钻杆与钢制钻杆摩擦磨损性能对比研究

Comparison on Friction and Wear Performance of Titanium Alloy Drill Pipe and Steel Drill Pipe under Drilling Conditions

钛合金材料由于具有高的比强度、低弹性模量,优异的韧性、疲劳性能和耐蚀性,已经成为深井、超深井及大位移水平井工况环境下钻杆及井下工具的热门候选材料,但在钻井条件下对钛合金钻杆的摩擦磨损性能缺乏研究,与钢制钻杆的性能优劣缺乏对比数据。通过硬度试验、冲击磨损试验、往复摩擦和模拟工况摩擦磨损对比试验,对钛合金钻杆和钢制钻杆的摩擦磨损性能及表面形貌进行对比分析。结果表明,由于抗划痕性能和硬度的差异,钛合金钻杆材料耐冲击磨损性能低于钢制钻杆材料,尤其在100r/min的中等冲击频率下钛合金钻杆材料耐冲击磨损性能明显低于钢制钻杆材料;在空气中的往复磨损试验中,钛合金钻杆材料的摩擦系数显著低于钢制钻杆,与岩石对磨时为典型的磨粒磨损机制,与金属对磨时为典型的粘着磨损机制;在钻井液环境中,钛合金钻杆的耐摩擦磨损性能不如钢制钻杆,但在水基钻井液中,钛合金钻杆与岩石材质对磨时,其耐磨性能最强、摩擦系数最低。建议在使用钛合金钻杆钻井时采用水基钻井液。下一步研究应提高钛合金材料耐磨性能或进行表面处理以提高钛合金钻杆的耐磨性。

Titanium alloy materials,due to their high specific strength,low elastic modulus,excellent toughness,fatigue resistance,and corrosion resistance,have become popular candidate materials for drill pipe and downhole tools under the operating conditions of deep wells,ultra-deep wells,and large displacement horizontal wells.However,there is a lack of research on the friction and wear performance of titanium alloy drill pipe under drilling conditions,and a lack of comparative data on the performance of steel drill pipe.This paper compares the friction and wear performance and surface morphology of titanium alloy drill pipe and steel drill pipe through hardness tests,impact wear tests,reciprocating friction,and simulated operating conditions friction and wear comparison tests.The results show that due to the difference in scratch resistance and hardness,the impact wear resistance of titanium alloy drill pipe materials is lower than that of steel drill pipe materials,especially at a medium impact frequency of 100 r/min.The impact wear resistance of titanium alloy drill pipe materials is significantly lower than that of steel drill materials.In the reciprocating wear test in the air,the friction coefficient of the titanium alloy drill pipe material is significantly lower than that of the steel drill pipe,with a typical abrasive wear mechanism when rubbing against rock and a typical adhesive wear mechanism when rubbing against metal.In a drilling fluid environment,the friction and wear resistance of the titanium alloy drill pipe is not as good as the steel drill pipe,but in water-based drilling fluid,when the titanium alloy drill pipe rubs against rock material,its wear resistance is the strongest and the friction coefficient is the lowest.It is suggested to use water-based drilling fluid when drilling with a titanium alloy drill pipe.Further research should focus on improving the wear resistance of titanium alloy materials or carrying out surface treatment to improve the wear resistance of titanium alloy drill pipe.