本文選題：溫度　切入點：醋酸濃度　出處：《西安科技大學》2017年碩士論文　論文類型：學位論文

【摘要】：由于油氣田所處的環(huán)境十分復雜,在其開采和生產運輸中,環(huán)境中大量的腐蝕介質會對石油工程采集輸送管材造成很嚴重的腐蝕,嚴重影響工業(yè)生產進程,給社會經濟帶來巨額的損失同時破壞環(huán)境。因此油氣集輸管材的腐蝕研究有很重要的意義和應用價值。L245M鋼是油氣田集輸管道中的常用材料,而關于這種鋼材的研究內容較少,本課題著眼于研究L245M管材在油氣田采集運輸中的腐蝕問題,通過模擬油田采出水條件研究不同溫度條件和不同醋酸濃度分別與HCO3-和Cl-對L245M鋼的腐蝕影響。本文主要通過模擬浸泡實驗、掃描電鏡和XRD衍射分析等檢測方式研究L245M管材在不同條件的腐蝕介質中腐蝕速率和產物膜的變化;利用動電位極化曲線和交流阻抗法研究管材在不同條件的腐蝕介質中的電化學特征變化情況。研究表明:溫度對L245M鋼的CO_2腐蝕有顯著影響,在中低溫階段(≤90℃),平均腐蝕速率隨著溫度的升高而加快。常溫下(30℃時)L245M鋼在高Cl-濃度的溶液中,CO_2腐蝕主要為均勻腐蝕,當溫度升高至60℃表面發(fā)現(xiàn)局部腐蝕,局部腐蝕反應隨著溫度升高而變得劇烈。在飽和CO_2的碳酸氫鈉模擬水溶液中,加入醋酸會提高L245M管材的腐蝕速率,并隨著醋酸濃度的增大腐蝕速率不斷加快。在不含醋酸和醋酸含量較低時腐蝕產物中可以檢測出碳酸亞鐵的存在,當醋酸濃度達到3000ppm時,腐蝕產物中沒有發(fā)現(xiàn)碳酸亞鐵,說明醋酸濃度達到一定程度時會形成可溶解的醋酸亞鐵,改變了腐蝕產物膜的化學成分。當模擬溶液中不含醋酸時,腐蝕反應主要受碳酸控制,溶液中加入醋酸時腐蝕反應受碳酸和醋酸的協(xié)同性控制,當醋酸濃度增加到2000ppm及以上時腐蝕反應主要受醋酸的控制,碳酸的作用變得微弱。在含Cl_的溶液中,醋酸會提高L245M的腐蝕速率,還會誘發(fā)L245M在較低溫度下發(fā)生局部腐蝕,醋酸的加入對管材試樣的腐蝕反應起促進作用。
[Abstract]:Because the environment of oil and gas field is very complex, in its exploitation and production and transportation, a large amount of corrosive medium in the environment will cause very serious corrosion to the pipeline of petroleum engineering acquisition and transportation, which will seriously affect the industrial production process. Therefore, the corrosion study of oil and gas gathering and transportation pipes is of great significance and application value. L245M steel is a common material in oil and gas field gathering pipeline, but the research content of this kind of steel is less. This paper focuses on the corrosion problem of L245M pipe in oil and gas field acquisition and transportation. The corrosion effects of HCO3- and Cl- on L245M steel at different temperatures and different acetic acid concentrations were studied by simulating oilfield produced water conditions. The changes of corrosion rate and product film of L245M pipe in different conditions were studied by scanning electron microscopy and XRD diffraction analysis. The electrochemical characteristics of pipes in different corrosion media were studied by potentiodynamic polarization curve and AC impedance method. The results show that temperature has a significant effect on the CO_2 corrosion of L245M steel. At the middle and low temperature (鈮，

本文編號：1590036