N80-1油管在火驱稠油开采过程中的失效原因分析  

Analysis on Causes for Failure of N80-1 Tubing as Occurring during Process of Heavy Oil Fire-flooding Exploitation

作　　者：周勇[1] 夏文斌[1] 赵映辉[1] ZHOU Yong;XIA Wenbin;ZHAO Yinghui(Hengyang Valin Steel Tube Co.,Ltd.,Hengyang 421001,China)

机构地区：[1]衡阳华菱钢管有限公司,湖南衡阳421001

出　　处：《钢管》2018年第4期18-22,共5页Steel Pipe

摘　　要：采用宏观、金相、XRD等手段,对N80-1油管在新疆稠油热采井火驱工艺开采过程中断裂的原因进行分析。分析认为:该断裂为过载断裂,导致油管过载断裂的主要原因是火驱过程中原油燃烧温度过高,使油管发生高温软化。原油燃烧生成的高CO_2分压导致CO_2腐蚀严重,腐蚀使管体发生点蚀和壁厚减薄,燃烧过程中钢管表面的高温氧化也导致壁厚减薄,都会加速管体发生过载断裂。指出C-Mn系油管不适合用于稠油热采井火驱开采工艺,建议选用Cr-Mo系调质钢种的稠油热采专用管。Analyzed are the causes for failure of the N80-1 tubing as occurring during the fire-flooding process for thermal exploitation of a certain heavy oil well in Xinjiang via such methods as macrostructure testing, metallographic analysis and XRD. It is identified via the analysis that the fracture of the said tubing is a kind of over-load fracture. And the main reason for such fracture of the tubing is that it suffers from softening in high temperature service due to over-high temperature from crude oil combustion. And the high CO2 differential pressure generated from crude oil combustion creates relatively severe CO2 corrosion which causes pitting-corrosion of the pipe body, and reduces the pipe wall thickness. In addition, the pipe surface oxidation under high temperature during combustion process also reduces the wall thickness, which, in turn, promotes the over-load fracture of the pipe body. Finally, it is concluded that in general, the C-Mn series tubing is not suitable for fire-flooding thermal exploitation of the heavy oil well as above mentioned. Accordingly, it is suggested to use the Cr-Mo series special pipes made in quenched-tempered steel for serving heavy oil thermal exploitation.

关 键 词：N80-1油管 稠油 火驱工艺 热采专用管 断裂 CO2腐蚀 高温软化 

分 类 号：TG115[金属学及工艺—物理冶金] TE931.2[金属学及工艺—金属学]