The Casing And Coupling Thread Thermal Stress Finite Element Analysis And Strength Evaluation Of Thermal Production Well

Steam process technology is one of the most important effective method to exploitviscous oil,in thermal process,the casing and the casing’s connecting thread will produce greatthermal stress,the stress is easy to make the casing and casing joint produces the yield andfracture. So in this paper, the thermal process Wells casing and casing in the connectionbetween the screw thread was calculated. Get the calculation parameters of finite elementanalysis of the heat transfer boundary conditions.On the condition of steam temperature is305℃and steam injection temperature260℃, to analysis the wellbore fluid parameters andtheir change rule, acquire the casing temperature in the casing thermal stress analysis, and getthe data of wellbore pressure and cement sheath’s temperature.According to the casing’sstructure and working condition in thermal production well,and the interaction ofstratum,casing and cement sheath.Established a whole plane strain finite element model ofcasing, cement sheath and stratum.On the condition of steam temperature is305℃and steaminjection temperature260℃, calculate the casing stress.Obtained the equivalent stress andsafety coefficient of different specifications casing and steel grade and evaluate thestrength.Taking the pre-tightening force, axial force and temperature load into account, tosimplify the threaded into axisymmetric structures,and establish Casing connection threadnonlinear finite element model. On the condition of steam injection temperature260℃,get thecasing joint contact stress analysis and sealing performance evaluation. Take the factors ofgeometry,cement sheath, mechanical parameters,stratum mechanical parameter,casingpressure,temperature and other factors into consideration,to do the finite element analysis ofcasing and cement sheath,get the influencing factors and influence rule of casing and cemnentsheath.