钻井液固液分离旋流器壁面磨损特性

针对石油钻井过程中，由于钻井液中泥沙等固体颗粒产生的冲蚀磨损导致的旋流器失效问题，采用CFD-DPM模型开展以非牛顿流体为钻井液时旋流器冲蚀磨损研究，探讨不同流速、稠度系数、流动性指数、含砂体积比和入口倾角对旋流器内壁冲蚀磨损的影响。结果表明：旋流器内壁磨损呈螺旋状，锥段处磨损率随着半径的减小而增大，底流口处是受损最为严重的部位；在流速5～15 m/s、含砂体积比1%～9%时旋流器的最大冲蚀率随着流速增大呈指数型增长，冲蚀面积明显扩张；低流速下含砂体积比对最大冲蚀率影响较弱，而高流速下最大冲蚀率与含砂体积比呈正相关；入口倾角的增大同时增大了向下的轴向速度，使得颗粒能更快地到达底流口减小了与壁面的接触，其冲蚀率呈线性减小；最大冲蚀率随稠度系数的增大整体呈现平缓下降的趋势，随着流动性指数的增大而急速下降，流动性指数对冲蚀破坏的影响相比稠度系数更剧烈一些。

Wall Wear Characteristics of Hydrocyclone for Solid-liquid Separation of Drilling Fluid

Aimed at the failure problem of hydrocyclone caused by erosion and abrasion of solid particles such as sediment in the drilling fluid during the oil drilling process,the erosion wear of hydrocyclone with non-Newtonian fluid as drilling fluid was studied by using CFD-DPM model.The effects of different flow rates,consistency coefficient,fluidity index,sand volume ratio and inlet inclination angle on the erosion wear of hydrocyclone inner wall were explored.The results show that the wear of the inner wall of the cyclone is in a spiral shape,the wear rate of the cone section increases with the decrease of the radius,and the underflow port is the most severely damaged part.When the flow velocity is from 5 m/s to 15 m/s and the sand volume ratio is from 1% to 9%,the maximum erosion rate of the hydrocyclone increases exponentially with the increase of the velocity,and the erosion area obviously expands.The sand volume ratio has a weaker effect on the maximum erosion rate at low flow velocity,while the maximum erosion rate is positively correlated with sand volume ratio at high flow velocity.The increase of the inlet inclination angle increases the downward axial velocity at the same time,so that the contact of the particles with the wall is reduced because the particles can reach the underflow port faster,and the erosion rate decreases linearly.The maximum erosion rate shows a gentle downward trend with the increase of the consistency coefficient,and decreases rapidly with the increase of the fluidity index.The influence of fluidity index on erosion damage is more severe than that of consistency coefficient.