定边采油厂油水井井筒腐蚀控制技术可行性研究与分析

发布时间：2018-08-27 15:16

【摘要】：对定边采油厂不同层位产出液水质进行了分析,并采用挂片失重法在现场和室内对其进行了腐蚀性研究。结果表明:延长组的产出液分离水多为CaCl_2型,高矿化度腐蚀为主,尤其是Cl-引起的点蚀;延安组产出液分离水多为NaHCO,主要腐蚀原因是SRB引起的细菌腐蚀、硫化氢腐蚀;腐蚀速率随着油井深度增加而增加,在750~1750 m范围内腐蚀速率增速最快;腐蚀速率随CO_2含量的增加而增加,对延安组影响更明显;同一H2S浓度下,p H降低,腐蚀速率升高,高温(80℃)下H2S浓度200 mg/L时,腐蚀速率最大,低温(28℃)下随着H2S浓度增加腐蚀速率增大;腐蚀速率随着流速的增加而增大,且在0.5 m/s后增速加快。合成了咪唑啉季铵盐、喹啉季铵盐和喹啉双季铵盐,以季铵盐为母体缓蚀剂,添加助剂制成三类固体缓蚀剂,并通过溶解性、缓蚀性等性能评价筛选最优配方。结果表明:咪唑啉季铵盐为25%、WLN10%、分散剂10%、聚乙二醇4000为50%、氯化钠5%的配方制成的固体缓蚀剂溶出速率最为稳定,平均溶出率为0.16 g/h,当其浓度为100 mg/L,温度60℃,在常压饱和CO_2产出液分离水中对A3钢缓蚀率为84.1%。合成了喹啉季铵盐(KLLHB),对其分散剂、复配助剂进行筛选,同时评价复配缓蚀剂的缓蚀、阻垢、杀菌性能。结果表明:最佳复配缓蚀剂为KLLHB-Z(15%KLLHB+10%表P9+20%表27+10%WLN+15%ZMP+1%WIK);当KLLHB-Z浓度为50 mg/L,40℃,168小时条件下腐蚀速率为0.0109 mm/a;在浓度分别为200 mg/L、100 mg/L时,阻垢率达到83%、对SRB杀菌率达到100%;加药浓度在小于150 mg/L的时候,缓蚀效果优于中原29#,成本价格只有中原29#的0.48倍。自行设计了油井环空连续加药装置、注水系统定量加药装置,将KLLHB-Z现场应用,用挂片失重法评价应用效果,结果表明:KLLHB-Z在油井、注水井使用,浓度为200mg/L时,对钢片的腐蚀速率控制在了0.076 mm/a以下,油井产出液含铁量下降率平均达到了44.3%。
[Abstract]:The quality of liquid produced in different layers of oil production plant was analyzed, and the corrosion of the liquid was studied in the field and indoor by using the method of weightlessness. The results show that the main reasons for the water separation in Yanchang group are CaCl_2 type, high salinity corrosion, especially the pitting corrosion caused by Cl-, and the main corrosion causes of NaHCO, in Yan'an formation are bacterial corrosion caused by SRB and hydrogen sulfide corrosion. The corrosion rate increased with the increase of oil well depth, and increased with the increase of CO_2 content. The corrosion rate increased with the increase of CO_2 content, and decreased with the concentration of H2S, and the corrosion rate increased at the same H _ 2S concentration, and the corrosion rate increased with the increase of CO_2 content. At high temperature (80 鈩，

本文编号：2207665