自旋转岩屑清洗工具模拟计算与分析

摘要

The existing cutting removing tool removes the cuttings in the annular through drill pipe rotation.The low RPM of drill pipe may hinder the tool's cleaning efficiency.In view of this,a self-rotating cutting removing tool has been designed.The tool allows the blade achieving high-speed rotating and cutting removing through the internal turbine in drill pipe.The working flow field of the tool is numerically simulated by computational fluid dynamics.The structure of the turbine blade is then designed.The cutting removing performance of the developed tool has been analyzed in streamline,velocity field and torque.The results show that the flow rate of the new developed tool is 1.4 times higher than that of the fixed blade wellbore cleaning tool.The average circumferential vortex velocity at high RPM is about 0.78 m/s higher than that at low RPM,which indicates that the tool can improve significantly the cutting carrying and removing capacity of the fluid,making it preferable for cutting carrying and removing.The conclusion could provide theoretical support for the subsequent development and application of self-rotating cutting removing tool.%现有岩屑清洗工具通过钻杆旋转对环空岩屑进行清洗,因钻杆转速较低,所以会影响工具的井眼清洁效率.鉴于此,设计了一种自旋转岩屑清洗工具.该工具可通过钻杆内部涡轮来实现叶片的高速旋转清洗.采用计算流体动力学对该工具的工作流场进行数值模拟分析,并设计了涡轮叶片的结构.从流线图、速度场和扭矩等角度对工具的清洗能力进行分析,分析结果表明:自旋转岩屑清洗工具比叶片固定式井眼清洁工具的流速提高了1.4倍,高转速下的平均周向涡流速度比低转速下的平均周向涡流速度提高约0.78 m/s.这说明自旋转岩屑清洗工具可使流体携岩和清岩的能力迅速提高,更有利于岩屑的携带和清除.所得结论可为自旋转岩屑清洗工具后续的研制和应用提供理论支持.