水下采油树AISI 8630材料的冲蚀模型研究

Study on Erosion Model of AISI 8630 Material for Subsea Christmas Tree

海洋开采油气中的固体颗粒会对水下采油树造成冲蚀磨损,致使其承压能力下降。为此,对水下采油树的常用材料AISI 8630的微观冲蚀机理进行了研究。通过扫描电镜拍摄了冲蚀坑表面微观样貌并采用冲蚀试验装置进行了气固冲蚀试验,系统地分析了颗粒粒径、冲击速度、冲击角度、冲击时长和颗粒质量流量5个因素对材料的冲蚀影响规律,得到了AISI 8630材料的冲蚀模型,并与DNV、E/CRC、Oka冲蚀模型及试验数据进行了对比分析。研究结果表明:当冲击角度低于15°时,冲蚀率随冲击角度的增大而增大,冲击角度在15°与30°之间时,冲蚀最严重,冲击角度大于30°时,冲蚀率随冲击角度的增大而逐渐减小;随着冲击速度的增大,冲蚀率呈幂式增长;当颗粒粒径小于200μm时,冲蚀率随颗粒粒径的增大而增大,当粒径大于200μm时,随着粒径的增大,冲蚀率基本维持稳定;AISI 8630材料冲蚀模型的最大误差为2.67%。所得结论能为海洋油气开采工程提供技术指导。

The solid particles in the offshore oil and gas production will cause erosive wear of the subsea Christmas tree,which will reduce its pressure bearing capacity.For this reason,the micro-erosion mechanism and law of AISI 8630,a commonly used material of subsea Christmas tree,is studied.Through scanning electron microscopy to photograph the surface microcosmic appearance and gas-solid erosion test,the erosion model of AISI 8630 material is obtained,and is analyzed and compared with the erosion model and test data of DNV,E/CRC and Oka.The research results show that when the impact angle is lower than 15°,the erosion rate increases with the impact angle.When the impact angle is between 15°and 30°,the erosion rate is the most serious.when it is larger than 30°,the erosion rate decreases with the impact angle.As the impact velocity increases,the erosion rate increases exponentially.When the particle size is less than 200μm,the erosion rate increases with the particle size.When the particle size is larger than 200μm,the erosion rate remains basically stable with the increase of particle size.The maximum error of the AISI 8630 material erosion model is 2.67%.The study conclusions can provide technical guidance for offshore oil and gas exploration projects.