CALCULATION OF CREEP PRESSURE ON WORN CASING SUBJECTED TO NONUNIFORM LOADING IN CREEP STRATUM
A research on the behavior of worn casing subjected to salt loading is done in this paper. The viscoelastic model is adopted to simulate the mechanical behavior of creep stratum. However, the elastoplastic model with linear hardening is used to study that of casing. The F.E. model was built on several parts including of worn casing, cement sheath, hydrate area and salt stratum. Such factors as geologic, engineering-oriented, and combined geologic and engineering-oriented are studied in order to illustrate the pressure distribution outside casing. The calculator program was developed to search for the optimal iterative factor automatically to accelerate its convergence. Furthermore, the Successive Over Relaxation Method (SOR) was adopted to solve large-scale FEM equations. It indicates that the maximum external pressure is in the same direction with the minimum terrestrial stress and the opposite is also right. The external pressure of the worn zone was greatly increased. So compared with the nonuniform terrestrial stress, the external pressure is more sensitive to casing wear. These numerical results can be used to guide casing design in oil and gas fields.
Chuan-Kui Zheng De-Li Gao Cheng-Jin Tan
Institute of Petroleum Engineering in CUP, Telephone 0086 10 8973-3702
国际会议
第九届工程结构完整性国际会议(The Ninth International Conference on Engineering Structural Integrity Assessment)
北京
英文
2007-10-15（万方平台首次上网日期，不代表论文的发表时间）