Study On The Deformation Performance Of The Oil Casing With Large Expansion Rate

Expandable tubular technology is one of the new technologies in the oil drilling industry.The ultimate goal of this technology is to achieve a single borehole diameter drilling completion.Expanding pipe material selection and process optimization is the key to restricting the development and application of expandable tube technology.Currently,most expandable tube is still made of API casing,of which the expansion rate is less than 25% and the yield ratio is about 0.75.Many researchers devoted themselves to invent a new expandable tubular with high performance,low cost and high expansion rate.However,seldom research focused on the modification of raw materials.Based on the existing successful research experience at home and abroad,this paper put low carbon steel A,low carbon steel B and low carbon steel C as the research object,on which we utilized the physical experiment and the finite element analysis process as the research means.First,According to the critical temperature of three kinds of materials,make the critical quenching process and low carbon steel C for annealing and quenching and tempering,the organizational characteristics of different materials under different treatment processes are obtained by OM,SEM and TEM analysis.Then the mechanical properties of these three kinds of materials are obtained by unidirectional static tensile experiment under different heat treatment process.Steels perform low yield strength and continuous yield characteristics and high work hardening performance and high strain rate sensitivity after critical quenching process.Finally,the expansion property of steels were measured at different expansion properties of expansion after different heat treatment processing,and the use of finite element analysis to simulate and obtain the influence of expansion with different expansion rate,strain hardening coefficient(K value),work hardening exponent(n value)and coefficient of friction between the sleeve and the expanding cone performance.The relationship among microstructure,mechanical properties and swelling Deformation of the tube has been established.It can be concluded that the expandable tube with high performance,low cost and high expansion rate is obtained.