原油集输管道H2S/CO2内腐蚀影响规律的试验研究

Experimental Study on the Influence of H2S/CO2 on the Internal Corrosion of Crude Oil Gathering and Transportation Pipeline

随油田开发过程的不断进行,油田原油集输管道的腐蚀问题日益突出,引发了不可忽视的安全隐患。以西南某油田具有代表性的原油集输管道材质--X65为研究目标,采用室内腐蚀试验的方法,通过电化学测试和电子扫描显微镜测试,对比分析了缓蚀剂、腐蚀垢层、H2S浓度等条件对原油集输管道内腐蚀的影响规律,并深入分析了其腐蚀机理。结果表明:腐蚀垢层的存在对原油集输管道内壁面的腐蚀反应过程和缓蚀剂的缓蚀效果具有阻碍作用;低浓度的H2S对腐蚀速率有抑制作用,而高浓度的H2S对腐蚀速率有促进作用;对裸钢试样而言,H2S浓度变化通过影响腐蚀产物膜影响腐蚀过程;针对含腐蚀垢层的金属试样,H2S浓度变化通过影响溶液中腐蚀性物质含量从而影响腐蚀过程。

With the continuous development of oil field,the corrosion problem of crude oil gathering and transportation pipeline in oil field has been more and more prominent,which causes a non-ignorable safety danger. In this paper,taking X65,a representative material of crude oil gathering pipeline in southwest China,as the research goal,the effects of corrosion inhibitor,corrosion scale layer and H2S concentration on the internal corrosion of crude oil gathering pipeline were compared and analyzed by means of electrochemical test and electron scanning microscope. In addition,the corrosion mechanism was deeply analyzed. Results showed that the existence of corrosion scale layer hindered the corrosion reaction process and corrosion inhibition effect of corrosion inhibitor on the inner wall of crude oil gathering pipeline. Moreover,low concentration of H2S could inhibit the corrosion rate,while high concentration of H2S could promote the corrosion rate. For bare steel samples,the change of H2S concentration affected the corrosion process by affecting the corrosion product film. As for metal samples with corrosion scale layer,the change of H2S concentration affected the corrosion process by controlling the content of corrosive substances in the solution.