油田污水系统硫化氢的危害及其治理

油田地面系统因硫酸盐还原菌繁殖导致硫化氢不断增长,是长期注污水开发的油田所面临的普遍问题。简述了油田污水中硫化氢的危害以及常用的硫化氢去除和增长控制技术,并重点介绍了河南油田的三个应用实例:其一,采用两级普通曝气处理聚合物配制污水,在气水比(V/V)=1∶2时,残留硫化氢含量小于1 mg/L;其二,普通曝气与缓蚀杀菌剂结合控制腐蚀,单级曝气气水比(V/V)=1∶(7~10)的条件下,硫化氢含量从50~60 mg/L下降到5~10 mg/L,再添加FH-8型缓蚀杀菌剂25 mg/L,腐蚀率从1 mm/a下降到0.2 mm/a;其三,固相催化曝气氧化与生物抑制技术相结合,实现硫化氢的彻底去除和控制,用于高温聚合物驱油的污水配制聚合物,在气水比(V/V)=1∶1时,硫化氢含量从25 mg/L下降到0.5 mg/L以下,生物抑制剂则使沿程硫化氢增长量不超过0.5 mg/L。催化曝气氧化除硫与普通曝气除硫相比,具有曝气量小、除硫迅速彻底的优点。对于对硫化氢含量要求严格的系统,固相催化曝气氧化与生物抑制技术结合,在技术和经济可行性方面具有明显的优势。

Harm of Hydrogen Sulfide and the Ways of Control in Oilfield Produced Water

The continuous increase of hydrogen sulfide (H2S) caused by the reproduction of sulfate reducing bacteria in the surface system is a troublesome issue commonly faced by those oilfields carrying out re-injection of produced water. This article gave a sketch of the harm of H2S and the common ways of removal in oilfields, and emphatically introduced three practical examples in the practice of Henan Oilfield. First, a common 2-stage aeration process, with an air-water ratio(v / v) of 1 : 2, was used in the treatment of the water for polymer preparation. The residual H2S was less than 1 mg/ L. Second, in another system, for the purpose of slowing corrosion, the common 1-stage aeration was used with a corrosion inhibiting bactericide to control corrosion. At an air-water ratio(v / v) of 1 : 7 to 1 : 10, the content of H2S was reduced from 50 ~60 mg/ L to 5 ~10 mg/ L, and the corrosion rate was reduced from 1 mm/ a to 0. 2 mm/ a when the 25 mg/ L inhibiting bactericide was added. Third, a new developed technique of solid catalyzed aeration, along with addition of a bacterial inhibitor, was applied to comprehensively remove the H2S and prevent it from reproduction in the water for polymer preparation. The thickness of H2S decreased from 25 mg/ L to 0. 5 mg/ L even when the air-water ratio(v/ v)was lowered to 1 : 1, and the increase of H2 S along the flow was less than 0. 5 mg / L with adding of a bacterial inhibitor. As a new sulfide removing technique, solid catalyzed aeration has many advantages over traditional aeration, such as lower air demand, more rapid and more complete removal of H2 S, etc. In systems where H2 S must be strictly limited, the combination of solid catalyzed aeration and bacterial inhibitor is more feasible than other common methods both technically and economically.