H_2S/CO_2共存聚合物钻井液中腐蚀产物膜分析  

Corrosion Product Scale Analysis in Polymer Drilling Fluid Containing H_2S/CO_2

作　　者：万里平[1] 孟英峰[1] 李皋[1] 舒小波[1] 魏纳[1] 周华 

机构地区：[1]西南石油大学"油气藏地质及开发工程"国家重点实验室,四川成都610500 [2]新疆油田工程技术公司,新疆克拉玛依834000

出　　处：《应用基础与工程科学学报》2012年第5期863-873,共11页Journal of Basic Science and Engineering

基　　金：国家自然科学基金"气体钻井腐蚀/冲蚀规律研究"(50974106)资助

摘　　要：随着酸性气田的不断开采,其钻采环境中的腐蚀机理及井下管材的优选已成为研究的热点.通过室内高温高压腐蚀试验,并结合扫描电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS),研究S135钻杆钢在H2S/CO2共存聚合物钻井液中气相与液相的腐蚀产物膜成分差异,探讨腐蚀机理.结果表明,S135钻杆钢气相和液相腐蚀速率都随温度升高和CO2分压增大而增加,气相腐蚀较液相严重,呈局部腐蚀形貌,气相腐蚀产物表面凹坑较大,液相腐蚀产物较为均匀且致密性强,以均匀腐蚀为主.气相和液相腐蚀产物膜中都含有C、O、S、Fe、Si五种元素,且腐蚀产物成分差别不大,主要成分为Fe3O4、FeS、α-FeOOH、FeS2,以及少量的Fe7S8和Fe3S4,此外在腐蚀产物膜表面还夹杂有硅酸盐物质.钻杆钢腐蚀主要来源于二氧化碳腐蚀、氧腐蚀、硫化氢腐蚀、单质硫腐蚀以及腐蚀产物膜与钢材本体间电偶腐蚀.With the successive development of sour gas fields, the study on corrosion mechanism and the optimization of downhole strings in drilling and oil production process have become the research focus. Through the high temperature and high pressure corrosion test and with the aid of scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), the composition difference and corrosion mechanism of corrosion scales in vapor and liquid phases of S135 drill pipe steel were studied in polymer drilling fluid under H2S/CO2 coexist environment. The results showed that the corrosion rate of S135 steel increased with the temperature and CO2 partial pressure raise both for vapor and liquid phases. For corrosion scale in vapor phase, the corrosion extent was serious than liquid, the corrosion morphology become local corrosion and the pits of corrosion scale surface was larger than liquid. But for liquid phase corrosion, corrosion products were more uniform and dense. Corrosion scales contain C, O, S, Fe, Si elements both for vapor and liquid phases, and the composition of corrosion scales was not very different, mainly composed of Fe3O4, FeS, α-FeOOH, FeS2, and a small amount of Fe7S8 and Fe3S4. Moreover, the surface of corrosion scales was also mixed with silicate material. The corrosion of drill pipe steel came from carbon dioxide corrosion, oxygen corrosion, hydrogen sulfide corrosion, elemental sulfur corrosion, and galvanic corrosion between corrosion product film and steel.

关 键 词：硫化氢腐蚀 二氧化碳腐蚀 XPS分析 腐蚀产物膜 钻杆钢 聚合物钻井液 

分 类 号：TE242.9[石油与天然气工程—油气井工程] TE982