摘要
目的缓解渤海某油田混合注水出现严重的CO_2/H_2S腐蚀、现场检测挂片的点腐蚀非常明显等问题。方法首先合成一种适合该油田工况的咪唑啉季铵盐(LH-31),再通过复配得到最优的缓蚀剂配方。结果利用动态高温高压釜,在95℃、0.15 MPa CO_2(含100μg/g H_2S)、总压0.5 MPa N_2、流速1.5 m/s、试验时间72 h条件下,测得空白平均腐蚀率为2.01 01 mm/a,点腐蚀速率1.1106 mm/a。添加40 mg/L的LH-31后,平均腐蚀率降至0.1000 mm/a,点腐蚀速率降至0.5789 mm/a。LH-31的红外谱图中,在879.31 cm^(-1)出现一个吸收峰,可能是季氮原子与相邻碳之间的伸缩振动,说明形成了环状季铵盐类化合物。LH-31与硫脲和苯甲酸钠之间具有协同效应,添加4%硫脲和3%苯甲酸钠组成的高效复合缓蚀剂2E,可将平均腐蚀速率降至0.0200 mm/a,点腐蚀速率降至0.0751 mm/a。极化曲线测试表明缓蚀剂2E为阳极抑制型缓蚀剂。缓蚀剂2E在现场进行了试验,通过旁路腐蚀试验测试1 d后,前后加注40 mg/L的缓蚀剂2E,试片的平均坑深由0.139μm降低至0.0258μm。结论缓蚀剂2E能有效抑制该渤海油田混合注水的均匀腐蚀和点腐蚀。
The work aims to reduce the serious CO2/H2S corrosion problems of water injection on offshore oilfield in the Bohai sea and the serious pittig corrosion of the test coupons.An imidazoline quaternary ammonium salt LH-31 applicable to the oilfiled conditions was synthesized and the optimum corrosion inhibitor was obtained through molecule compound.At 95℃and 0.15 MPa CO2(including 100μg/g H2S),the blank average corrosion measured at total pressure of 0.5 MPa N2 and flow velocity of 1.5 m/s for 72 hours was 2.0101 mm/a and pitting corrosion rate was 1.1106 mm/a.The average corrosion decreased to 0.1000 mm/a and pitting corrosion rate reduced to 0.5789 mm/a after 40 mg/L LH-31 was added.LH-31 had an absorption peak in 879.31 cm?1.A stretching vibration might occur between the nitrogen atoms and adjacent carbons and the quaternary ammonium salts might be formed.LH-31 had synergistic effect with thiourea and sodium benzoate.The efficient compound corrosion inhibitor 2E composed of 4%thiourea and 3%sodium benzoate could reduce the average corrosion to 0.0200 mm/a and the pitting corrosion rate to 0.0751 mm/a.The polarization curve test showed that the corrosion inhibitor 2E was the anode type of corrosion inhibitor.After the corrosion inhibitor passed the bypass corrosion test for 1 day,the average depth of the test coupon was reduced to 0.0258μm from 0.139μm after adding 40 mg/L of 2E.The corrosion inhibitor can effectively inhibit the uniform corrosion and pitting corrosion of mixed water injection in the Bohai Sea.
作者
陆原
赵景茂
张茂
陈胜利
胡廷
张勇
LU Yuan;ZHAO Jing-mao;ZHANG Mao;CHEN Sheng-li;HU Ting;ZHANG Yong(School of Materials Science and Engineering,Beijing University of Chemical Technology,Beijing 100029,China;CNOOC Ener Tech-Drilling&Production Co.,Tianjin 300450,China;CNOOC Energy Technology&Services Limited,Beijing Branch,Beijing 100027,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2018年第10期59-65,共7页
Surface Technology
