注空气驱套管材质腐蚀规律与机理研究

Study on corrosion law and mechanism of air injection casing

关键词:  注空气驱  氧含量  点蚀  溃疡腐蚀  腐蚀速率

Key words:  air injection  oxygen content  pitting corrosion  ulcer corrosion  corrosion rate

摘要:

随着采油技术的发展,注空气采油技术受到国内外很多油田的重视,但空气中氧的存在,会给油田管线及其他设备带来严重的腐蚀问题。为了明确注空气驱的腐蚀主导因素、腐蚀规律及腐蚀机理,利用高温高压反应釜模拟工况条件对油田所提供的20#与L360两种材质进行腐蚀试验,通过金相显微镜与X射线衍射仪对腐蚀后试样的形貌与产物进行表征分析,研究不同氧含量、压力与温度条件下材质的腐蚀规律与机理。通过分析得出:腐蚀速率随着氧含量、压力与温度的升高而升高；从金相显微镜观察可知,腐蚀类型为点蚀与溃疡腐蚀；XRD分析得到腐蚀产物的主要成分为铁的氧化物。腐蚀的主导因素为氧含量,油田在生产作业中应适当控制所注空气的氧含量。 

Abstract:

With the development of oil production technology, air injection technology has been paid much attention by many domestic and foreign oil fields, but the oxygen in the air will cause serious corrosion problems to oil pipeline and other equipment. In order to make clear the main corrosion factors, corrosion law, corrosion mechanism of air injection, we have conducted corrosion tests of 20# and L360 by using high temperature and high pressure reactor to simulate the working conditions. The morphology and products of corroded samples are characterized and analyzed by metallographic microscope and X-ray diffractometer, the corrosion law and mechanism of different oxygen content, pressure and temperature are studied. The corrosion rate increases with the increase of oxygen content, pressure and temperature. Metallographic observation shows that pitting corrosion and ulcer corrosion are the main corrosion types, and XRD analysis shows that the main components of the corrosion products are iron oxides. To sum up, the leading factor of corrosion is oxygen content, and the oxygen content of injected air should be properly controlled in the production of oil field.