天然气工业2018，Vol.38Issue(1)：89-94,6.DOI:10.3787/j.issn.1000-0976.2018.01.011
高温高压超深气井油管柱屈曲行为研究
Buckling behaviors of tubing strings in HTHP ultra-deep wells
摘要
Abstract
Classical theoretical formulas for the buckling of pipe strings derived by previous researchers may not completely and accurately describe the non-uniform or incomplete sinusoidal buckling or helical buckling forms around the bottom of tubing strings in HTHP ultra-deep gas wells.In this paper,a finite element mechanical model for analyzing the buckling behaviors of tubing strings in HTHP ultra-deep wells was established by using the software ANSYS.With an ultra-deep well in the Tarim Oilfield as an example,systematic analyses were conducted on the buckling of tubing strings with regard to buckling configuration,horizontal displacement,tubing-casing contact pressure.The results are revealed in two aspects.First,the proposed finite element analysis model for the buckling behaviors of tubing strings in HTHP ultra-deep wells can be used to highlight buckling configurations throughout the entire hole.It can be seen that the interval between the central point and the packer under complicated mechanical conditions is in inhomogeneous,or incomplete sinusoidal or helical buckling forms.Second,in such cases with an axial pressure of 205 kN at the bottom of the tubing string,the contact sections at the top and bottom of the string may experience self-locking due to sinusoidal and helical buckling,respectively.The self-locking phenomenon may lead to permanent buckling of such strings.In conclusion,the proposed model can be used to highlight buckling configurations,contact pressures and frictions during tubing-casing buckling.The model provides a reliable technique and foundation for analyses related to buckling configurations,friction damages,failures and relevant prevention measures.To prolong the service life of tubing strings,it is necessary to apply suitable lifting forces,enlarge the dimensions of tubing strings at bottom,promote wellhead pressures or properly reduce productivities.关键词
超深井/油管柱/屈曲行为/接触力学/有限元法/正弦屈曲/螺旋屈曲/自锁现象Key words
Ultra-deep well/Tubing string/Buckling behavior/Contact mechanics/Finite element method/Sinusoidal buckling/Helical buckling/Self-locking phenomenon引用本文复制引用
练章华,牟易升,刘洋,许定江..高温高压超深气井油管柱屈曲行为研究[J].天然气工业,2018,38(1):89-94,6.基金项目
国家自然科学基金项目“极端条件下气井油套管端力学行为及其螺纹密封机理研究”(编号:51574198). （编号:51574198）
