气体钻井钻具内气体冲蚀机理研究

Study on the Inside Drilling Rig Erosion in Gas Drilling

采用计算流体动力学方法建立高速气体冲蚀无刺孔钻杆接头和具有腐蚀坑的钻杆接头模型。无刺孔的钻杆接头内,只有钻杆内产生腐蚀坑后,流场才变为钻杆本体刺漏的主要影响因素之一;钻杆带有腐蚀坑时,其钻杆内的最大流速远大于无腐蚀坑钻杆内的最大流速;钻杆的穿刺及断裂主要是由于裂纹从钻杆内壁向外壁不断扩展的结果。

Based on this,drill pipe sub of no acanthopore and drill pipe sub of corrosion pits model for drill pipe erosion of high-speed gas are established by use of the computational fluid dynamics （CFD） method.Through the analysis of the drill pipe subgas flow field ,the drill pipe sub velocity field ,some conclusions are drawn that the change of the flow field is not the main factors of the leak of drill pipe ontology in the drill pipe sub of no acanthopore,the change of the flow field become one of the main factors only when the drill pipe have corrosion pits.The maximum velocity of the drill pipe with corrosion pitsare is much larger than the drill pipe of no corrosion pit.The puncture and fracture of drill pipe are mainly due to the crack propagation from the drill pipe wall to the outside.