Numerical Simulation And Experimental Study On The Forming Process Of Metal Seal For Deep Well

In this paper,the research object focus on a self-developed new bridge plug metal seal for which mechanical analysis,numerical simulation and microstructure observation are applied to optimize the structural of the metal seal and combination of machining and hydraulic forming process.Meanwhile,the feasibility of high efficiency cross wedge rolling replacing the process of machining is also discussed.The details are as follows:Through the packer test and simulation analysis,to clarify the reason of metal seal cracks in the sitting seal rectangular slot and arched thin-walled circular turning inner root.To flip the rectangular slot and circular thin-walled inner root fillet over size as design variables,constructing mathematical model,the optimization results show that the flip right angled groove fillet over 1.5 mm,thin root fillet over 3.0mm arc edge,sitting seal metal seal sealing property and stability are good,no crack defect.Firstly,the cracks on the sealing surface of the new kind of metal sealing in bridge plug formed by machining is studied,then the reason is obtained by means of mechanical analysis and microstructure observation under different condition.Subsequently,the process of hydraulic forming for the metal sealing is proposed.The test results show that the quality of sealing surface is optimal when the punch pressure is 180 MPa and the holding time is 5s,and there are no cracks on the surface after setting.The cracks could be eliminated because the radial compressive stress of hydraulic forming from the results of mechanical analysis and microstructure observation.The setting performance of the metal sealing is greatly improved by the process of hydraulic forming comparing with original machining method.In order to solve the problem that the metal seal is difficult to be machined and the production efficiency is low,the wedge cross rolling forming process of the outer surface of the metal seal is put forward.DEFORM-3D is used to optimize the design of the mold and the process parameters.The results show that when the forming angle ? is 30 °,the widening angle ? is 8 °,the rolling speed V is set to 408mm/s,and the rolling temperature T is set to950 ° C in the metal cross wedge rolling process,the basic dimensions of the parts meet the design requirements,the maximum error is no greater than 4%,the maximum rolling force of about 120.0KN,The feasibility of the cross wedge rolling of metal seal is verified theoretically.