油田产出水的腐蚀及防护研究

本文在对长庆油田的靖北、吴旗、油房庄和大水坑区块采油装置发生腐蚀原因分析的基础上,开展了产出水的缓蚀和杀菌试验研究。结果表明,引起井下管柱及集输管线腐蚀的因素主要有产出水矿化度高、H2S和SRB含量高、部分水质溶解氧超标以及井下存在CO2伴生气和不均匀结垢;优选的CI-2缓蚀剂具有较好的缓蚀效果,加量为50mg/L时,可使产出水的腐蚀速度由0.125mm/a降至0.012mm/a,缓蚀率达90%以上;经杀菌剂筛选,BI-2和BI-3对SRB、TGB具有较好的杀菌效果,为了防止产生抗药性,采用BI-2和BI-3交替加药。

Study on Corrosion and Protection of Oil-field Produced water

Based on the analysis of corrosion causes in Jingbei, Wuqi, Youfangzhuang and Dashuikeng block of Chanqing oilfield, corrosion inhibition and sterilization research of produced water are developed on this paper. The experimental results indicated that corrosion causes of downhole strings and gathering pipeline are mainly high salinity, high content of H2S and SRB, out-of standard of dissolved oxygen in produced water, CO2 associated gas and non-uniform scaling. Optimal CI-2 corrosion Inhibitor can effectively inhibit corrosion of produced water, which can decrease the corrosion rate of produced water from 0.125mm/a to 0.012mm/a at dosage of 50mg/ L, whose inhibition efficiency is over 90%. Screened BI-2 and BI-3 bactericide can provide good bactericidal effect on total general bacteria(TGB), and sulfate reduction bacteria(SRB). In order to prevent SRB and TGB from producing drug-resistance, BI-2 and BI-3 were used in turn.