全通径滑套球座打捞机构关键技术研究

球座可提出式全通径滑套可通过球座打捞机构将各级球座一次提出井口，实现管内全通径，要求球座打捞机构轴向插入载荷小，承载能力强。为此，设计了新型高承载球座打捞机构，采用理论计算和有限元分析方法，分析了齿根面锥度和承载面角度对轴向插入载荷和承载能力的影响规律，并确定了最优参数。分析结果表明，与常规球座打捞机构相比，新型高承载球座打捞机构轴向插入载荷降低了75%，当齿根锥度为1:16时，轴向插入载荷约为2 kN，轴向极限抗拉强度达到500 kN。当承载面角度小于90°时，随着齿根锥度增大，球座打捞机构的轴向承拉能力随之增强，轴向插入载荷随之降低。高承载球座打捞机构模拟入井试验一次打捞成功，表明高承载球座打捞机构能满足现场应用要求，为提高球座打捞成功率提供了新的技术途径。 

Key Technology on Ball Seat Fishing Mechanism of Full Bore Size Sleeves

The retrievable sleeve fishing mechanism can pull a multistage ball-seat out of hole in one trip,for a full bore size inside the pipe string,with lower axial insertion loads and high load bearing.Under such circumstances,an innovative high load bearing mechanism has been developed for fishing multi-stage ball seats.Through theoretical calculation and finite element analysis,the impact of tooth root taper and loading bearing angles on axial insertion load and load bearing capacity has been analyzed,and the optimal parameters determined.Results of analyses demonstrated that the innovative heavy-duty ball-seat fishing mechanism can reduce axial insertion loads 75% compared with conventional devices.When the tooth root taper is 1:16,the axial insertion load is approximately 2 kN,while the maximum axial insertion load is as much as 500 kN.When the load loading angle is less than 90°,the axial load bearing capacities of fishing mechanism inrease as the tooth root taper increases and the axial insertion load decreases.The high load bearing fishing mechanism has been simulated to run in hole,with successful operation in one trip thus demonstrating that the fishing mechanism can effectively meet the demands of wellsite application,and provide a new way for enhancing the success rate of ball seat fishing.