洲城油田注水系统腐蚀结垢原因分析与防治措施

Analysis of reasons and preventative measures on corrosion and scaling in water injection system of Zhoucheng Oilfield

通过室内垢样试验和水质分析,提出洲城油田注水管线腐蚀与结垢的主要原因是污水中的微生物特别是SRB细菌大量繁殖,SRB细菌大量繁殖后产生硫化氢等,加剧污水管线腐蚀与结垢。对腐蚀与结垢的机理进行分析,提出有针对性地添加缓蚀阻垢药剂、化学杀菌剂,进行污水紫外线处理和选择有效的耐SRB腐蚀材料、实施阴极保护等措施。对已经结垢的管线,分析比较化学清洗、清管器清洗和高压水射流清洗等除垢方法的优劣,建议优先考虑非化学清洗方法;加强对回注污水的达标处理,建立在线腐蚀监测系统,预防与治理相结合。

Through tests of indoor scaling sample and analysis of water quality, this paper comes out with a con clusion that the cause of corrosion and scaling of water injection pipeline is the result of a large number of breeding of micro-organism in wastewater, especially SRB bacteria that will produce H2S and loam, which can make the cor rosion and scaling worse. The paper also elaborates the mechanism of corrosion and scaling and points out several prevention and control measures, including adding targeted corrosion and scaling inhibitor or chemical fungicides, UV treatment of wastewater, choosing effective SRB corrosion-resistant material, implementation of cathodic protection. For pipelines that already have scaling, after analyzing scale removing methods such as chemical cleaning, pig cleaning,high-pressure water jet cleaning, etc. , it is suggested that, from the view of safety, non-chemical cleaning methods is the main priority. To enhance meeting the standard of treatment of reinjected oilfield wastewater,an on- line corrosion monitoring system should be established to achieve the purpose of combination of prevention and controlling.