钻井液对钻杆接头冲蚀规律的试验研究

钻杆受到钻井液的冲蚀会有不同程度的损伤,若在钻杆接头部位出现冲蚀坑就可能使钻杆失效,引发钻井事故。鉴于此,通过试验分析了钻井液流量、粘度、密度、钻井液中固相颗粒体积分数及固相颗粒粒径对钻杆接头冲蚀量的影响规律。结果表明,钻井液密度对钻杆接头的冲蚀影响基本可以忽略;钻井液流量与粘度的增大会导致冲蚀量增大;固相颗粒是造成钻杆接头冲蚀的主要原因,固相颗粒体积分数的增大与粒径的减小均会导致冲蚀量增加。冲蚀量较大的位置在钻杆内外接头结合处、公接头与钻杆本体焊接后端台阶处以及公接头出口处。因此,应在强度等条件允许的情况下,改进钻杆接头部分的结构与尺寸,使流动平稳地过渡,防止因截面突变而引起涡流的产生或流速的加快,以尽量减少冲蚀量;在钻井过程中,应当采取切实有效的措施加强对固相的控制。

An experimental study of the erosion law of drilling fluid on the drill pipe sub

The drill pipe will suffer different degrees of damage under the erosion of drilling fluid. If there appears the erosion pit at the tool joint, the drill pipe may fail and thus a drilling accident will arise. Considering this problem, the experiments were carried out to analyze the law to affect the erosion on the tool joint relating to the drilling fluid parameters, including the flowrate, viscosity and density as well as the solid particle volume fraction and the solid particle size. The result shows that...