FF-HH材料选择

材料选择基于来自客户井内流体的组分的表（井1，2，4，6和7），我们计算CO2和H2S的最小分压值为256.5(5,000*5.13/100)和356.5PSI(5,000*7.13/100)PSI.以上计算是基于这些井的关井压力为5,000PSI.CO2的分压腐蚀性定义是根据第17版的API6A标准中的附录A,表A1作出的.当CO2的分压值大于30PSI时,通常就被认为是高腐蚀性,在这种情况下对于阀体部分要选择FF级材料(不锈钢).在这里所谈到的H2S的分压是356.5PSI(0.05PSI,最小分压值是按照NACEMR0175定义的),工作条件被认为是酸性环境并且极具腐蚀性.综合考虑这样大的CO2和H2S分压值,依据卡麦隆在多年类似条件下选择材料的经验,应该选择HH级(在AISI4130的内部嵌入INC.625材料)的材料.HiTerry,BasedonthetableofthewellfluidcompositionsfromRogerTanthattheminimumcalculatedpartialpressuresofCO2andH2Sare256.5(5000*5.13/100)psiand356.5(5000*7.13/100)psirespectivelyforthewells1,2,4,6&7(theshut-inwellpressurebasedon5000psi).TheCO2partialpressuredefinesthecorrosivityoftheretainedfluidsasdefinedinAPI6A,17thEdition,AppendixA,TableA1.WhenthepartialpressureofCO2ishigherthan30psi,theretainedwellfluidisconsideredtobemoderatelytohighlycorrosive.Asageneralruleforthesecases,FFtrim(stainlesssteelmaterial)shallbeselectedforbodycomponents.WithrespecttotheH2Spartialpressureof356.5(0.05psi,theminimumpartialpressuredefinedbyNACEMR0175),theserviceconditionisconsideredtobesourandverycorrosive.ThereforeinconsiderationofthehighCO2andH2Spartialpressures,andCameronexperienceinmaterialselectioninthesimilarconditions,HHtrim(inc.625inlayonAISI4130)wouldbeselectedandproposedforcustomer'sreview.Hopeabovewillhelp!Bestregards,