高强度油气长输管道腐蚀与防护研究进展

Research Progress on Corrosion and Protection of High-strength Long-distance Oil and Gas Pipeline

油气管道腐蚀是威胁管道安全的重要因素。随着我国对能源需求的增加，应用大管径、高压力、高强度管道是未来的发展趋势。X100／X120管道研究日益增多。根据腐蚀环境的不同，可以将高强度油气管道的腐蚀分为海水腐蚀、土壤腐蚀和大气腐蚀。其中，陆地管道大多采用埋地敷设，土壤腐蚀成为影响我国管道运行安全的主要因素，土壤中微生物中厌氧型硫酸盐还原菌（SRB）的存在加速了管道腐蚀，CO2分压通过影响CO2溶液中化合物的溶解度和pH值成为影响CO2腐蚀的主要因素。管道运行过程中油气流速和管道压力也会对腐蚀产生影响：油气流速越大，管道腐蚀速率越快；压力对原油管道腐蚀速率的影响较小。对天然气管道腐蚀速率的影响较大。相比管道本身，焊缝区更容易被腐蚀。对管道进行内外防腐处理是减缓管道腐蚀速率最有效的方法，常见的管道内防腐技术主要包括选择耐腐蚀性强的管道材料、在油气资源中加入缓蚀剂、在管道内表面增设内涂层以及衬里技术；外防腐技术主要指外涂层技术和阴极保护技术。没有任何一种技术可以适用于所有情况下的管道防腐，需要根据管道所处环境及项目特点选择最合适的技术。未来的研究方向是将各种防腐技术结合起来，研发低成本、高效率、无污染的防腐技术。

Corrosion on oil and gas pipeline is an important factor threatening pipeline safety.Along with the increase of energy demands in China,the pipeline with large diameter,high pressure and high strength will be the future trend.There are more researches on X100/X120 pipeline.According to the corrosion environment, the corrosion on high-strength oil and gas pipelines can be classified into sea water corrosion,soil corrosion and atmosphere corrosion.Among them,the land pipeline is buried under the ground mostly,and soil corrosion is becoming the main influencing factors of operation safety of the pipelines in China.Anaerobic sulfate-re dueing bacteria （SRB）of the mieroorganiam in the soil accelerated the pipeline corrosion,and CO2 partial pressure becomes the main factor of influencing CO2 corrosion through the effect on solubility of the com- pound and pH value in the CO2 solution.Flow rate of oil and gas and pipeline pressure also have influence on the corrosion during the operation of the pipeline.That is,corrosion rate of the pipeline is rapid under higher flow rate of oil and gas, and the pressure have few influences on the corrosion rate of the petroleum pipeline and great influence on that of the natural gas pipeline.Compared with the pipeline itself,welding-line area is easier to be corroded.Antiseptic treatment of the pipeline inside and outside is the most effective method of slowing down the corrosion rate of the pipeline.The common antiseptic technologies for the inner pipeline include selecting pipeline material with strong anticorrosion ,adding corrosion inhibitor into the oil and gas resources ,setting inner coating at inner surface of the pipeline and lining technology.The common antisep- tic technologies for the external pipeline include outer coating technology and cathode protection technology.No technologies were fit for all pipeline corrosion.The suitable technology may be selected according to the envi- ronment of the pipeline and characteristics of the project.All kinds of antiseptic technologies should be inte- grated in the future research,and the antiseptic technologies with low cost,high efficiency and no pollution should be developed.