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I摘要在油气田开发过程中，CO2腐蚀是困扰世界各国油气工业发展的一个极为突出问题，也成为今后油气工业及油管生产厂家的一个急需解决重要课题。本文针对川西某气井井筒中的CO2气液两相腐蚀现象，在实验室进行研究并研发出针对CO2腐蚀体系的气液两相缓蚀剂。针对川西某气井CO2腐蚀体系，开展了介质温度、CO2分压、介质流速、Cl-浓度及pH值等对N80套管钢腐蚀行为的影响，结果表明，CO2腐蚀体系对N80钢气相腐蚀速率明显小于液相腐蚀速率，动态腐蚀速率显著高于静态腐蚀速率。温度和CO2分压对N80钢腐蚀的影响均存在一个极值；Cl-浓度和pH值变化对液相腐蚀速率比较明显，而对于气相腐蚀速率甚微。针对CO2气液两相腐蚀的特点，通过合成液相成分的双咪唑啉季铵盐和气相成分的多单元吗啉环己胺缓蚀剂，再与含硫有机物、炔醇类缓蚀剂及表面活性剂B进行正交实验复配，得到抑制CO2腐蚀的气液两相缓蚀剂SM-12B，其配方为双咪唑啉季铵盐:多单元吗啉环己胺:含硫有机物:炔醇类:表面活性剂B=3:3:1:1:2。通过失重法研究了SM-12B缓蚀剂的缓蚀率，结果表明，使用SM-12B缓蚀剂存在一个极值浓度为400mg/L，其气相缓蚀率达到77%以上，液相缓蚀率达到85%以上；SM-12B缓蚀剂在温度小于90℃具有相对较高的缓蚀率，属于低温型缓蚀剂；SM-12B缓蚀剂适用于CO2分压低于1.0MPa的CO2腐蚀环境；随着介质流速的增大，气液两相缓蚀率都降低；Cl-浓度对气相缓蚀率影响不大，而在一定程度上Cl-浓度能明显影响液相缓蚀率；SM-12B缓蚀剂在16~24h内，SM-12B缓蚀剂一直保持较高的缓蚀率。用极化曲线、扫描电镜及XRD等研究了SM-12B缓蚀剂的缓蚀机理，极化曲线结果表明，SM-12B缓蚀剂的缓蚀作用类型为以阳极为主的混合型缓蚀剂，其缓蚀机理为“负催化效应”，即缓蚀剂的缓蚀效应主要是通过吸附改变电极反应的活化能，从而减缓腐蚀反应的速率。扫描电镜观察表明添加SM-12B缓蚀剂后，腐蚀明显受到抑制，腐蚀仅仅发生在试样加工过程中试样产生的纹理处，且不十分明显，比较轻微；XRD研究表明，腐蚀产物为FeCO3。关键词CO2两相腐蚀；缓蚀剂；咪唑啉衍生物；吗啉衍生物；缓蚀性能IIAbstractCarbondioxidecorrosionisanextremelyprominentquestiontopuzzleoil/gasindustryexhibitioninworldandbecomeanurgentresolvesignificantsubjectinoil/gasfielddevelopment.InviewofthetwophasecarbondioxidecorrosionphenomenoninmininginSichuangasfield,theoriginalsearchonecorrosioninhibitorofthetwophasecarbondioxidecorrosioninlaboratory.InviewofcarbondioxidecorrosionenvironmentinChuanxigasfield,theoriginalresearchwhatcorrosionrateofN80tubesteelthroughvaryingthemediatemperature,carbondioxidedifferentialpressure,mediumvelocityofflow,concentrationofCl-andpH,itindicatethatvaporphasecorrosionrateobviouslyissmallerthanliquidphasecorrosionrate,anddynamiccorrosionrateremarkablyismorethanstaticcorrosionrate.AnditisanextremevaluewhichtheaffectionbetweentheN80tubesteelcorrosionandCl-andpH;alsoconcentrationofCl-andpHobviouslyaffectliquidphasecorrosionrate,butseldomaffectvaporphasecorrosionrate.Inviewofthefeatureinthetwophasecarbondioxidecorrosion,thisthesisfirstsynthetisethequaternaryammoniumbio-imdazolineasliquidphasecomponentandpolyunitmorpholinecyclohexylamnoniummoietyasvaporphasecomponentandthenproceedtotheperpendicularityexperimentwiththesulfurousorganicsubstance,acetylenicalcoholcorrosioninhibitorandsurfaceactingagentB,andthelastgettheSM-12Bcorrosioninhibitionofthetwophasecarbondioxidecorrosion,itsmatchquaternaryammoniumbio-imdazoline,polyunitmorpholinecyclohexylamnoniummoiety,sulfurousorganicsubstance,acetylenicalcoholcorrosioninhibitorandsurfaceactingagentBratiothree,three,one,one,two.ThisthesisresearchedtheinhibitionofcorrosionofSM-12Bcorrosioninhibitorbyweightlessnessexperiments,andtheresultindicatethatitisanextremevalueofSM-12Bcorrosioninhibitorwhichis400mg/L,andthevaporphasecorrosioninhibitionratioismorethan77%,theliquidphasecorrosioninhibitionratioismorethan85%;SM-12Bcorrosioninhibitorwhichbelongtoalowtemperaturecorrosioninhibitorpresentuppercorrosioninhibitioninlessthan90℃;SM-12Bcorrosioninhibitorissuitforcorrosionenvironmentwhichcarbondioxidedifferentialpressureislowerthan1.0MPa;andconcentrationofCl-canobviouslyaffectliquidphasecorrosioninhibitionratio;thevaporandliquidphasecorrosioninhibitionratiobothdecreaseinthewakeofaccretingofthemediumvelocity;andSM-12Bcorrosioninhibitoralwaysmaintainuppercorrosioninhibitionratiofrom16hourto24hour.ThisthesisresearchedcorrosioninhibitionmechanismofSM-12Bcorrosioninhibitorbypolarization,SEMandXRD,andtheresultindicatethatcorrosioninhibitionofSM-12Bcorrosioninhibitorishybridtypecorrosioninhibitionwhichmainlyinhibitanode,thecorrosioninhibitionmechanismis“negativecatalysiseffect”,inhibitionofcorrosionofcorrosioninhibitorrevisehalfreactionofactivationenergybyattachmentsothatcorrosionIIIrateisslowdoun;whenSM-12Bcorrosioninhibitorisaddtocarbondioxidecorrosionenvironment,corrosionobviouslyisinhibited,andcorrosionlightly,corrosioninfibreoftheN80steelspecimenbySEM;XRDindicatethatcorrosionproductiscalciumcarbonate.Keywordthetwophasecarbondioxidecorrosion；corrosioninhibitor；imidazolineramification；morpholineramification；inhibitorybehaviour目录摘要.........................................................................................................................................IAbstract.....................................................................................................................................II目录........................................................................................................................................1第1章绪论..............................................................................................................................11.1论文研究目的意义......................................................................................................11.2国内外研究现状..........................................................................................................11.2.1气液两相腐蚀的产生及危害............................................................................11.2.2气液两相缓蚀剂国内外研究现状....................................................................21.3油套管腐蚀类型....................................................................