CAJ | 학술논문

为考察含 H2 S／CO2酸性气井不同井段3种常用套管钢（T95钢、110SS‐2Cr钢和825钢）的适用性及温度对其腐蚀行为的影响，利用高温高压釜在 H2 S分压0．55 M Pa、CO2分压0．75 M Pa、温度55～100℃条件下，对3种钢材的失重腐蚀性能进行了测试，并辅以扫描电镜观察腐蚀产物膜的微观形貌和能谱仪定性分析其化学成分，探讨了腐蚀机理。实验结果表明，模拟井筒腐蚀工况下，825钢腐蚀轻微，腐蚀速率远低于S Y 5329－2012《碎屑岩油藏注水水质指标及分析方法》规定的腐蚀控制指标0．076 mm／a；T95钢和110SS‐2Cr钢的腐蚀速率随温度的升高而增加，110SS‐2Cr钢的耐电化学腐蚀性能远优于T95；随着温度的逐渐升高，T95钢和110SS‐2Cr钢腐蚀产物膜变厚、结晶和结块趋势明显，主要成分是Fex Sy 、FeCO3和含有少量Cr的化合物，110SS‐2Cr钢腐蚀产物膜中，Cr含量比T95钢高，对基体的保护作用较强，因而在3个温度条件下的腐蚀速率均低于 T 95钢。结果表明，T 95钢用于油层套管井口段具有较好的经济性和适用性，825钢用在封隔器及以下井段具有较好的适用性，中间段油层套管采用110SS‐2Cr钢具有较好的适用性。
위고찰함 H2 S／CO2산성기정불동정단3충상용투관강（T95강、110SS‐2Cr강화825강）적괄용성급온도대기부식행위적영향，이용고온고압부재 H2 S분압0．55 M Pa、CO2분압0．75 M Pa、온도55～100℃조건하，대3충강재적실중부식성능진행료측시，병보이소묘전경관찰부식산물막적미관형모화능보의정성분석기화학성분，탐토료부식궤리。실험결과표명，모의정통부식공황하，825강부식경미，부식속솔원저우S Y 5329－2012《쇄설암유장주수수질지표급분석방법》규정적부식공제지표0．076 mm／a；T95강화110SS‐2Cr강적부식속솔수온도적승고이증가，110SS‐2Cr강적내전화학부식성능원우우T95；수착온도적축점승고，T95강화110SS‐2Cr강부식산물막변후、결정화결괴추세명현，주요성분시Fex Sy 、FeCO3화함유소량Cr적화합물，110SS‐2Cr강부식산물막중，Cr함량비T95강고，대기체적보호작용교강，인이재3개온도조건하적부식속솔균저우 T 95강。결과표명，T 95강용우유층투관정구단구유교호적경제성화괄용성，825강용재봉격기급이하정단구유교호적괄용성，중간단유층투관채용110SS‐2Cr강구유교호적괄용성。
In order to assess the applicability and effect of temperature on corrosion behavior ,the common specimens of three production casing steels(T95 ,110SS‐2Cr and 825 steel) in different depths were subjected to acidic solution containing both 0 .55 MPa H2S and 0 .75 MPa CO2 at 55-100 ℃for 72 h in an autoclave ,and micromorphologies and chemical compositions of corrosion products were obtained through scanning electron microscope (SEM ) and energy dispersive X‐ray (EDX) ,respec‐tively .The weight‐loss results show that the corrosion of 825 steel is slight according to the SY5329 standard ,and the corrosion rate of 110SS‐2Cr is lower than that of T95 steel ,which explains its bet‐ter anti‐electrochemical corrosion performance .Besides ,the corrosion rates of T 95 steel and 110SS‐2Cr steel increase as temperature rises .The microscopic analysis indicates that with temperature in‐creasing ,the corrosion products of T 95 steel and 110SS‐2Cr steel thicken and the tendency of crystal‐lization and agglomeration is obvious ,and the main chemical compositions are FexSy ,FeCO3 and small amount of Cr .It is noted that the Cr content of 110SS‐2Cr steel is higher than that of T 95 steel ,which accounts for the better protective effect and lower corrosion rate of 110SS‐2Cr steel .Therefore , T95 steel is suggested to apply at the wellhead of production casing for its economy and practicality , the 825 steel can be used below the packer of production casing with its higher expense ,110SS‐2Cr steel is appropriate to be used in the middle of production casing because of its poor SSCC resistance .