摘要
为深入了解20~#钢在复杂环境下的腐蚀失效情况,明确腐蚀失效的主要影响因素,以塔河油田混输管段为例,采用宏观分析、化学成分分析、拉伸性能和金相组织分析、扫描电镜及能谱分析、X射线衍射(XRD)分析等方法对其进行失效分析。结果表明:该管段腐蚀穿孔的主要原因是由腐蚀介质所引起的电化学腐蚀,腐蚀产物主要为FeCO_3、FeOOH、FeS、Fe OH·H_2O等,管道输送介质中的Cl^-、H_2S、CO_2、O_2是造成腐蚀穿孔的重要成分,其中H_2O是腐蚀介质的载体,CO_2影响最为显著,其次是H_2S。同时,由于该油田采出液具有高含Cl^-、高矿化度、高含H_2O、高含CO_2、高含H_2S、低pH值的特点,使管件有较强的腐蚀结垢特性,通过室内有无沉积物覆盖下的点腐蚀试验,进一步确定了管道沉积物对管道腐蚀失效的影响及规律,为今后金属管材的腐蚀控制提供了技术支撑。
In order to understand deeply the corrosion failure of 20^# steel in the complicated environment and define the main factors of corrosion failure, failure analysis was carried out on the oil and gas mixed pipeline section in Tahe oilfield by means of macroscopic analysis, chemical composition analysis, tensile property and metallographic analysis, scanning electron microscopy and energy spectrum analysis and X-ray diffraction analysis（XRD）. It is indicated that the main cause of corrosion perforation in this pipeline section is the electrochemical corrosion caused by the corrosive medium. The main corrosion products are FeCO3, FeOOH, FeS, FeOH·H2O and so on. The Cl^-, H2S, CO2 and O2 in the medium of pipeline transportation are the main compositions that lead to corrosion perforation. Among them, H2O is the carrier of corrosion, and CO2 has the most significant effect, followed by H2S. Besides, stronger corrosion scaling is presented on the pipeline due to the characteristics of high content of Cl^-, H2O, CO2 and H2S, high mineralization degree and low p H of the produced liquid in this oilfield. Finally, the effects and laws of pipeline sediments on pipeline corrosion failure were further determined by performing point corrosion tests with/without the coverage of sediment in the laboratory. It provides technical support for the corrosion control of metal pipelines in the future.
作者
唐世春
李雅娴
代维
赫文博
TANG Shichun;LI Yaxian;DAI Wei;HE Wenbo(SINOPEC Northwest Oilfield Company;School of Petroleum and Natural Gas Engineering,Southwest Petroleum University)
出处
《油气储运》
CAS
北大核心
2018年第8期909-915,共7页
Oil & Gas Storage and Transportation
关键词
集输管道
腐蚀穿孔
失效分析
沉积物
gathering pipeline
corrosion perforation
failure analysis
sediment
