The Working Mechanism And Simulation Analysis Of The Desirable Packer

With the increasingly complex geological environment faced by oilfield exploitation,the requirements for the design and manufacture of packers have been correspondingly improved,and the requirements for more convenient use and longer life have been gradually developed.Under complex and poor underground conditions,must use high quality removable packers in order to meet the economic and reasonable,but also to complete its sealing role.The design,production and processing of retrievable packers at home and abroad are still not perfect.In order to make retrievable packers obtain in field applications such as layered fracturing and acidification,layered sand control,layered production and closed water layers,etc.More stable and good results require solving the problems of mechanism and reliability.In this paper,based on the research and collation of a large number of literatures at home and abroad,combined with the practical working conditions of the removable packer working in the well,a dual-swath retrievable packer was designed to carry out the work of the key parts of the packer.Simulation studies,optimization of the parameters of the seal structure dimensions,and thus provide theoretical basis and method for analyzing the working performance of the packer in the downhole,etc.The main research contents of this article are as follows:Combined with the application background,the structural design of the bidirectionally anchored double-slip removable packer is completed.The detailed design of the structure of the components of the removable packer and the overall assembly design is performed with reference to the downhole tool design.Develop a foundation for follow-up finite element simulations of kinematics of removable packers.The mechanical model and parameter selection of the sealant cartridge were studied.By modeling the slips and cones of the removable packer,the stress distributions of the single slip and the six slips respectively with the cones were studied when the initial contact position between the slip and the cone was shown.The stress in the tapered zone is relatively large.The maximum stress is in the circular hole of the cone and spreads around the hole as the center.The maximum stress value is less than the yield strength of the cone material,and the material is used in a safe range.By selecting the type of threads of the connecting parts of the shells of the removable packer,the two connecting threads are mainly selected as the research object,and their three-dimensional models in the actual working conditions are simulated,and the results are compared and analyzed.Their various strength laws indicate that the trapezoidal thread strength is higher than the API thread,providing a theoretical basis for the selection and design of the shell thread of the removable packer.Through the preliminary design of the original size of the collapsible element of the retrievable packer,the finite element stress analysis was performed on the colloidal tube to obtain the optimized size.According to the reference literature,the first selection of the canister camber angle is 45.The final sealer performance is that the upper and lower cartridge heights are about 60 mm,the cartridge height is about 50 mm,and the cartridge thickness is about 21 mm.Good;and with the increase of the set load,the contact stress between the rubber tube and the casing increases;the maximum contact stress of the rubber tube increases first and then decreases with the increase of the annular space gap,and the gap is in the gap.The maximum is reached around 3 mm.Through analysis,in the curved section,the stress and axial tension of the tool of the retrievable packer vary greatly,and the stress and the axial tension gradually decrease with the change of the position of the downhole packer tool,but at the bending well Due to frictional resistance and the combination of downhole packer tool failure,the segmental mechanical effect caused a substantial increase in axial force.In summary,combined with the structural characteristics and working mechanism of the removable packer tool,the paper simulates and simulates the key parts of the removable packer,optimizes the size of the retrievable packer sealing element and the packer shells.Selection of connection threads between bodies provides a reference.