气田用缓蚀剂评选、复配及添加量研究

The Study on Corrosion Inhibitor Selecting, Compounding and Addition Quantity

针对某气田集输管道腐蚀极为严重这一状况,研究了适合该气田生产条件的缓蚀剂。首先,采用失重法对9种商品缓蚀剂进行了初步筛选,然后在模拟实际工况条件下对筛选出的缓蚀剂进行了复配研究,最后采用动电位极化曲线对具有较好缓蚀率的复配缓蚀剂进行了最佳添加量测试。实验结果显示:在9种不同类型的缓蚀剂中,以咪唑啉类缓蚀剂和季铵盐类缓蚀剂的缓蚀效果最好;咪唑啉类缓蚀剂和季铵盐类缓蚀剂在本实验条件下具有很好的协同效应,且复配比为60:40时的缓蚀效果最好可达97%;复配缓蚀剂属于阴极抑制型缓蚀剂,其添加量为200mg/L时,缓蚀率可达99%以上。

The corrosion of the gathering pipeline in a gas field was extremely serious and the corrosion inhibitor for this gas field was studied. Firstly,weight loss method is performed in this study for preliminary selection among 9 corrosion inhibitors. Then,corrosion inhibitors which are selected are remixed under the imitation operating mode condition. Finally,by measurements of potentiodynamic polarization curve some compounding inhibitors that inhibit the corrosion rate well are investigated for reaching optimum addition quantity. The result shows imidazoline corrosion inhibitor and quaternary- ammonium-salt corrosion inhibitor have better inhibition effect. In this experimental system, these two kinds of inhibitor have good synergistic effect and when compound ratio is 60：40, the best inhibition effect is shown that the inhibition rate is 97%. Compounded inhibitor is cathodic type inhibitor while the inhibition rate is above 99% when add up to 200mg/L.