球形腐蚀坑油管下入弯曲井段安全性评价

Safety evaluation of running into curved portion for oil tube containing spherical corrosion pit

采油工业中,油管在出现腐蚀坑后一般仍会反复使用,而腐蚀坑会导致油管在下入弯曲井段过程中出现屈服甚至失效,针对该问题,在弹塑性有限元理论基础上,建立了油管下入弯曲井段的力学模型.研究了腐蚀坑深度、腐蚀坑数量以及腐蚀坑间距对油管在不同曲率井段中下入安全性的影响.结果表明,腐蚀坑的深度和间距是决定油管能否再次下入的主要因素,而腐蚀坑的体积和数量则会影响到油管的使用时间和使用次数.初步得到了一套球形腐蚀坑油管在弯曲井段中下入的安全性评价方法,研究结果可为球形腐蚀坑油管在弯曲井段中的下入安全性分析提供理论依据和数值参考.

In the oil extraction industry,the oil tube will be repeatedly used even though some corrosion pits appear.However,the corrosion pits may cause the yield or even failure of oil tube when the oil tube runs into the curved portion.In order to solve the above-mentioned problem,a mechanical model for the oil tube to run into the curved portion was established based on the elastoplasticity finite element theory.The effect of depth,quantity and interval of corrosion pits on the running safety of oil tube into the portion with different curvature was studied.The results show that the depth and interval of corrosion pits are the main factors to determine whether the oil tube can be used again,while the volume and quantity of corrosion pits will affect the service time and use frequency.A set of safety evaluation method of running into the curved portion for the oil tube containing spherical corrosion pits is obtained,and the results can provide the theoretical basis and numerical references for the oil tube containing spherical corrosion pits to run into the curved portion.