某油井P110油管接箍断裂失效分析  

Failure Analysis of P110 Tubing Coupling Fracture in an Oil Well

作　　者：付小坤 田磊 郭福贵 杨兴 Fu Xiaokun;Tian Lei;Guo Fugui;Yang Xing(SINOPEC Northwest Oilfield Company,No.3 Oil Production Plant,Xinjiang,Aksu,843000)

机构地区：[1]中石化西北油田分公司采油三厂,新疆阿克苏843000

出　　处：《安全、健康和环境》2024年第5期41-46,共6页Safety Health & Environment

基　　金：国家科技重大专项(2016ZX05053);塔里木盆地碳酸盐岩油气田提高采收率关键技术示范工程。

摘　　要：塔河油田某油井P110油管入井服役15天发生接箍断裂,为了找到接箍断裂原因,指导后期采油安全生产,通过宏观形貌、化学成分、理化性能测试、能谱及扫描电镜分析等手段研究了油管接箍短期断裂的原因。结果表明,该管材接箍的断裂存在非金属夹杂物的影响,且冲击性能较差,未达到标准规范要求;螺纹接箍处存在流场诱导腐蚀,为H_(2)S与CO_(2)共同作用的腐蚀结果;螺纹牙根部产生了局部腐蚀坑,形成了疲劳源,疲劳裂纹扩展到一定程度下,在酸性腐蚀环境中产生了脆性断裂,断面有少量二次裂纹。由此得出该管材断裂失效主要是由非金属夹杂物、H_(2)S及CO_(2)引起的管材腐蚀、疲劳断裂造成的,且硫化物应力腐蚀开裂均对管材的断裂产生了影响。建议对高含H_(2)S井必须使用抗硫油管,并降低夹杂物含量,提升材质的热处理工艺,选择耐应力腐蚀开裂性能较强的材质。In order to find out the reason of the fracture and guide the safe production in the later stage of oil recovery,the causes of the short term fracture of the tubing coupling were studied by means of macroscopic morphology,chemical composition,physical and chemical properties,energy spectrum and scanning electron microscope analysis.The results showed that the fracture of the pipe coupling was affected by non-metallic inclusions,and the impact performance was poor,which did not meet the requirements of the standard specification.There was flow-field induced corrosion at the threaded coupling,which was the result of H_(2)S and CO_(2).Local corrosion pits were formed at the root of the thread tooth,forming a fatigue source,fatigue cracks extended to a certain extent,brittle fractures were produced in the acidic corrosion environment,and a small number of secondary cracks were found in the section.It was concluded that the fracture failure of the pipe was mainly caused by corrosion and fatigue fracture caused by non-metallic inclusions,H_(2)S and CO_(2),and the sulfide stress corrosion cracking had an effect on the fracture of the pipe.It was recommended to use sulfur-resistant tubing for Wells with high H_(2)S content,reduce the content of inclusions,improve the heat treatment process of materials,and select materials with strong stress corrosion cracking resistance.

关 键 词：腐蚀 疲劳 节箍断裂 P110油管 失效分析 

分 类 号：TE35[石油与天然气工程—油气田开发工程]