【作者】 李强；

【导师】 熊金平；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2011， 硕士

【摘要】 腐蚀问题日益成为油气田持续开发的主要障碍。油气田的采出液中往往伴生有H2S、C02等腐蚀性气体和腐蚀性离子等,这些腐蚀介质的存在及其浓度的变化,会导致油气田用钢遭遇不同程度的腐蚀,从而制约油气田的开发和生产,因此研究油气田用钢的腐蚀行为及其机理,并提出相应的防护方法迫在眉睫。目前,Crl3钢在饱和C02/H2S腐蚀介质中的腐蚀机理与防护技术的系统研究的报道较少。为此本文利用腐蚀失重法、电化学方法以及表面分析手段系统研究了Cr13钢在含不同浓度Cl-的饱和C02/H2S腐蚀介质中的腐蚀机理及其因素的影响,探讨了n-2-n型Gemini表面活性剂对Cr13钢的缓蚀作用,主要结论有：1.Cl-浓度对Cr13钢在饱和C02/H2S环境中的腐蚀行为影响规律在不同温度下,随着Cl-浓度的增加,Cr13钢的腐蚀速率不断升高,且都在Cl-浓度为200g/L时,腐蚀速率出现最大值；Cr13钢的腐蚀形式由均匀腐蚀逐渐转变为点蚀等局部腐蚀。在无Cl-或者Cl-浓度为20g/L时,腐蚀产物主要是致密性良好的FeS膜层；当Cl-浓度升高到100g/L时,腐蚀产物中出现了少量的Fe7S8,膜层逐渐疏松；在Cl-浓度为200g/L时,腐蚀产物膜主要是由Fel-xS组成。2.温度对Cr13钢在饱和C02/H2S介质中的腐蚀行为的影响规律在Cl-浓度较低时,腐蚀速率随着温度的增加先升高后降低,在温度为90℃时出现最大值。当Cl-浓度升高到100g/L和200g/L时,腐蚀速率随着温度的升高而不断加大。在25℃时,Cr13钢在饱和C02/H2S介质中腐蚀后腐蚀产物主要是致密性良好的FeS膜层；当温度升高到50℃时,腐蚀产物中出现了少量疏松的Fe7S8；在温度为120℃和150℃时,腐蚀产物膜主要是由Fel_xS组成。3.n-2-n型Gemini表面活性剂的缓蚀性能研究在不同温度时,n-2-n型Gemini表面活性剂对Cr13钢在含50 g/LCl-的饱和H2S/C02介质中腐蚀的缓蚀效率随着Gemini表面活性剂浓度的升高而不断增大；Gemini表面活性剂在金属表面吸附符合Langmiur吸附模型,且是一个白发过程。更多还原

【Abstract】 Corrosion has been increasingly becoming a major obstacle to the sustainable development of oilfields.Oil production fluid containing H2S, CO2, corrosive anions as well as others cause steel corrosion under temperature and pressure during oil production. It is imperative to study and protect corrosion as corrosion has restricted developing, manufacturing and transporting in oilfields.So far, a few papers about corrosion mechanism and protection methods of 13Cr steel have been published.Weight loss method, electrochemical measurement techniques and surface analytical technology were used to study the mechanism and main influence factors on 13Cr steel in CO2 and H2S saturated system. At the same time, the inhibition effect and mechanism of the surfactants to control corrosion of 13Cr steel in CO2 and H2S saturated system were discussed. The main conclusions are as follows:1. Effect of concentration of Cl- on Crl3 steel corrosion behavior in CO2 and H2S saturated system Corrosion rate of Cr13 steel in CO2 and H2S saturated system was accelerating as the concentration of Cl- increased at the different temperature, and reached the maximum value at 200 g/L Cl-. It was uniform corrosion at low concentration of Cl-, however, it changed to local corrosion as pitting corrosion when concentration of Cl- was up to 100 g/L Cl-.And the composition of corrosion products on 13Cr steel was affected by concentration of Cl-, mainly FeS at low concentration of Cl-, mostly FeS and low Fe7S8 at 100 g/L, and mainly Fe1-xS at 200 g/L.2. Effect of concentration of temperature on Cr13 steel corrosion behavior in CO2 and H2S saturated systemCorrosion rate of Crl3 steel in CO2 and H2S saturated system was accelerating as temperature increased at low concentration of Cl-, and reached the maximum value at 90℃.Corrosion rate of Crl3 steel was accelerating as temperature increased at 100 g/L and 200 g/L Cl-.And the composition of corrosion products on 13Cr steel was affected temperature, mainly FeS at low concentration of Cl-, mostly FeS and low Fe7S8 at low temperature, and mainly Fe1-xS at high temperature.3. Study on inhibition of n-2-n Gemini surfactantsInhibition efficiency of n-2-n Gemini surfactants effect on Cr13 steel CO2 and H2S saturated system containing 50 g/L Cl- was increased with the increasing of surfactants concentration at different temperature. The adsorption mechanism of this cationic gemini surfactants on steel surface in CO2 and H2S saturated system was found to be fitted with Langmuir adsorption model, and it is spontaneous process.更多还原