Zhongyuan oilfields are mainly located in Dongpu depression,where the geological conditions were extremely complicated and the external stress is abnormally high,the pipe used may fail in the radial direction owing to...Zhongyuan oilfields are mainly located in Dongpu depression,where the geological conditions were extremely complicated and the external stress is abnormally high,the pipe used may fail in the radial direction owing to well shrinkage caused by the creep of salt rock,leading catastrophic economic loss. Therefore this region has been wellkown as a touchstone for high collapse resistance casing since long before.In order to satisfy the requirement for high-collapse strength casing owing to the creep of salt bed stratum in Dongpu Depression region,BG140TT,BG150TT and BG160TT high-strength collapse resistance casing series were developed to better cope with the severe geological conditions.Among the casing series, a BG160TT non-API specification casing with collapse strength not less than 170 MPa were prepared.Up to present,all these high-strength collapse resistance casing have been successfully applied in the Dongpu Depression region.The research concept,mechanical properties,as well as application result were introduced in this paper.展开更多
The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were co...The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber.A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations.The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated.The effects of the angle between the cartridge and chamber,the cartridge case material,and the intermal impact pressure on the predicted headspace value were also analyzed.The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model.The internal impact pressure,pressure change rate,and cartridge material were all found to affect the predicted headspace.展开更多
文摘Zhongyuan oilfields are mainly located in Dongpu depression,where the geological conditions were extremely complicated and the external stress is abnormally high,the pipe used may fail in the radial direction owing to well shrinkage caused by the creep of salt rock,leading catastrophic economic loss. Therefore this region has been wellkown as a touchstone for high collapse resistance casing since long before.In order to satisfy the requirement for high-collapse strength casing owing to the creep of salt bed stratum in Dongpu Depression region,BG140TT,BG150TT and BG160TT high-strength collapse resistance casing series were developed to better cope with the severe geological conditions.Among the casing series, a BG160TT non-API specification casing with collapse strength not less than 170 MPa were prepared.Up to present,all these high-strength collapse resistance casing have been successfully applied in the Dongpu Depression region.The research concept,mechanical properties,as well as application result were introduced in this paper.
基金supported by the National Natural Science Foundation of China(Grant Nos.11372137 and 11602025)Equipment Development Department of the Central Military Commission of China(Grant No.301030905)。
文摘The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber.A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations.The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated.The effects of the angle between the cartridge and chamber,the cartridge case material,and the intermal impact pressure on the predicted headspace value were also analyzed.The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model.The internal impact pressure,pressure change rate,and cartridge material were all found to affect the predicted headspace.
