中文摘要：

针对目前钻井工程中钻杆内加厚过渡区岩屑颗粒冲蚀严重的现状,采用数值模拟方法对钻杆内加厚过渡区内钻井液流动和岩屑颗粒冲蚀问题开展研究,并采用全尺寸铝制试件进行冲蚀试验来验证模拟计算结果。结果表明：钻井液进入公接头内加厚区域后,流体静压经历了先增大后减小而后再增大3个阶段;钻井液从钻杆本体进入公接头内加厚区域后,流速迅速增大,在内加厚区域内保持了较高的数值,直至进入母接头后才逐步降低,且在公母接头连接区域存在流体滞留现象;钻杆过渡区内岩屑颗粒冲蚀较严重的区域有公接头入口端、公接头内部区域和公母接头连接处。

英文摘要：

Drilling fluid flow and cuttings grain erosion in heavy weight transition region inside the drill pipe were studied numerically and validated experimentally with full-scale test piece made of aluminum.The results show that the static pressure of drilling fluid increases when the fluid enters the transition section of drill pipe,and maintains at a lower level when fluid passes through the inner section of tool joint and increases when fluid enters the intersection of tool joint and tool pin.The velocity of drilling fluid increases when drilling fluid enters the transition section of drill pipe,and maintains at a higher level when fluid passes through the inner section of tool joint and decreases when fluid enters the intersection of tool joint and tool pin.The entrance section of the tool joint,the inner section of the tool joint and the intersection of the tool joint and pin are severely eroded and special attention should be paid to such locations.