Dynamic Analysis Of Rolling Shaper Repairing Shrinkage Deformation Casing

As oil fields are developed,the casing damage is increasing and has become an important constraint to field production.Therefore,in order to reduce economic losses in oil fields due to casing damage,research on plastic repair of deformed casing is needed.Compared with the traditional shaping technology,Hydraulic ball swage is great safer and more efficient casing shaping technology.The swage can shape the deformed casing at a time,with the advantages of small damage to the casing and large single diameter expansion.After the occurrence of casing damage,there is a certain residual stress inside the deformed casing,and this initial residual stress will have some influence on the shaping effect of the shrinkage deformation casing.Therefore,it is important to analyze the kinetics of roll forming repair of shrinkage deformation casing considering the initial residual stress.In this paper,considering contact nonlinearity and material nonlinearity,a three-dimensional dual nonlinear dynamics analysis model and numerical calculation method are established for rolling and shaping the shrinkage deformation casing considering the initial residual stress.A study of the effect of initial residual stress on the shaping of shrinkage deformation casing was carried out.The mechanical analysis of shrinkage deformation casing with a minimum through diameter of 114.5mm considering the initial residual stress is was carried out,and compared with the casing without considering the initial residual stress,we get,when considering the initial residual stress,the number of ball stages involved in the shaping of the minimum diameter of the casing by the shaper is reduced by 1 stage;the diameter expansion of the deformed casing after shaping is reduced by 1.22 mm,the out-of-roundness is increased by 0.3.There is little difference in residual stress.The initial residual stress has a greater impact on the effect of shrinkage deformation casing shaping.When considering the initial residual stress,a study was conducted on the ultimate through diameter which the shaper can safely pass the shrinkage deformation casing considering the initial residual stress in a single pass.The results show that considering the initial residual stress shrinkage deformation casing can be safely shaped once through the limit diameter of 115mm;with the increase in the minimum size of the shrinkage deformation casing through diameter,the casing of the out-of-roundness increased significantly,the residual stress decreased significantly,the through diameter change is very small.Analyzed the effect of different construction parameters on the consideration of the initial residual stress shrinkage deformation casing shaping effect。The results show that the influence of increasing shaft speed on the out-of-roundness and diameter expansion of casing is very small.With the increase of the rotation speed,the residual stress of the casing decreases,the diameter of the shaped casing expands,and the rolling pressure of the inner wall of the casing is more uniform.The optimal process parameters of shaping are 1mm/s shaft speed and 0.60rad/s rotational speed.Based on the best process parameters obtained,the effects of different materials on the shaping effect of shrinkage deformation casing considering the initial residual stress were analyzed.The results show that after shrinkage deformation casing with shaping material P110,the inner wall of casing was more uniform,but the diameter expansion of casing was the smallest,and after shrinkage deformation casing with shaping material J55,the inner wall of the casing was relatively less uniform,but the diameter expansion of the casing was the largest.The research results of this paper have some guiding significance for the construction of shrinkage deformation casing shaping site.