Research On Roll Forging Technology Of Folding Continuous Casing

In recent years,oil casing technology has developed rapidly,while expansion casing technology has become a core technology in oil casing.Traditional expansion casing expands itself fitting the shaft wall by the expansion cone head,and has many engineering applications in plenty of areas like restoration of the oil pipe and casing,column reinforcement,strata plugging,liner hanger.However the oil gas needs to be sealed because of the non-continuous structure,which causes the wellbore’s shrinking during the sealing,and it’s very difficult to guarantee the connection strength and tightness of the expansion casing’s connection.According to the CoilFlat-CT-Liner which is development by the German company Marinovition’s research,the author designs a "U" type continuous casing which can twine around and fold to a roller,in order to solve the problems that common oil casings are difficult to carry and go into the well,the difficulty of construction,insufficient strength of connect place etc.In this paper,the CoilFlat-CT-Liner is processed by means of roll forging,and the extrusion and roll forging process of casing is simulated by deform-3D finite element software,in the process of simulation,the deformation of each channel,the rule of metal flow and the maximum equivalent stress in the process of roll forging are revealed.Firstly,the groove and parameter design of the roll forging die are carried out,and the 3D solid modeling of the groove of different roll forging die is established.Through finite element simulation in the DEFORM,after comparing the forming of folding continuous casing section shapes,sizes,and stress distribution in the process of forming,the "U" groove scheme of the well-formed roll forging die was screened out.Secondly,the arc radius and rotary radius of the roll forging die are optimized and analyzed.When the lower mold arc radius is 97mm,the casing is well formed.When the rotary radius is 300mm,it can guarantee that under the premise of small force and good deformation of the folding continuous sleeve,the size of the roll forging die is the smallest,saving cost and convenient processing.Through simulation analysis,the optimal design scheme of roll forging die for forming CoilFlat-CT-Liner is studied,which provides important reference value for the die design of casing roll forging process.In this paper,according to the actual situation of industrial production,the process of roll forging is studied.The roll forging time and roll forging speed are mainly optimized,according to the calculation formula of roll forging times of metal plastic forming,it is decided that the experiment of this subject is divided into three times,and the equivalent stress value,metal flow velocity field,cross section of the forging parts after each roll forging process and the extension and relative width are analyzed.On the optimization of roll forging speed,selected four control groups for study analysis,analyzed travel-load distribution at different speeds,it has important guiding significance for the selection of production speed and tonnage of equipment in continuous casing production.Finally,according to the design concept of coilflat-ct-liner,a preliminary study was conducted on the scheme of folding continuous casing winding drum,which provided a new design idea for this new type of oil continuous casing.