产出聚合物对生产污水腐蚀与结垢的影响实验研究

Research on effects of residual polymer on the corrosion and scaling of the oilfield produced water

关键词:  产出聚合物 腐蚀 结垢 污水回注

Key words:  residual polymer, corrosion, scaling, sewage reinjection

摘要:

采用称量法与碳酸钙沉淀法相结合的结垢评价方法和常规的电化学腐蚀方法评价产出聚合物对生产污水腐蚀与结垢的影响。研究表明，较低浓度的产出聚合物会轻微加速溶液中Ca2+以垢的形式析出，主要是附着于容器壁的硬垢量增加，对水中游离的软垢影响不大。当产出聚合物质量浓度大于200 mg/L时，聚合物本身对Ca2+的螯合增溶作用占据优势，并逐步减弱溶液的结垢趋势。产出聚合物具有缓蚀作用，聚合物质量浓度为50 mg/L时，缓蚀率可达59.22%；对腐蚀后的污水具有螯合和分散固悬物的作用。产出聚合物与现场防垢剂、缓蚀剂均有协同作用，阻垢及缓蚀效果优于不含聚污水，对于污水回注具有积极意义

Abstract:

The effects of residual polymer on corrosion and scaling of the oilfield produced water were studied through gravimetric method combined with calcium carbonate precipitation method and conventional electrochemical etching method. The results show that the residual polymer with lower concentrations can accelerates the Ca2+ to the scale in the form of precipitation slightly, mainly increased the amount of hard scale attached to the vessel wall, little effect to the soft scale in the produced water. When the residual polymer concentration is greater than 200 mg/L, the polymer chelating solubilization to calcium is in the ascendant, and gradually reduced the scaling tendency of the solution. The residual polymer has corrosion inhibition, the corrosion rate can reach 59.22% with polymer concentration of 50 mg/L, it has a role of chelating the corroded sewage and dispersing the solid suspension. There is a synergy effect between the residual polymer and the field antiscaling agent, corrosion inhibitor, preventing scale and corrosion mitigation is better than that of excluding polymer sewage, it is of positive significance for sewage reinjection.