塔中四油田注水管线结垢腐蚀影响因素分析

Study of the Scaling and Corrosion Influence Factors of Water-injection Pipelines at Tazhong Fourth Oilfield

文章对塔中四油田注水管线结垢腐蚀影响因素进行分析,结果表明:影响结垢的主要因素为回注水中高浓度的钙离子、碳酸氢根离子形成的碳酸钙垢;影响腐蚀的主要因素为回注水质呈弱酸性,氯离子和硫化物含量高,氯离子和硫化氢的协同作用加剧了管道的腐蚀。另外,注水管线中井口流速慢,压力降低,注入水质不配伍等因素都会导致结垢腐蚀。因此,应主要选择针对碳酸钙类型的阻垢剂和防氯腐蚀缓蚀剂以减缓塔中四油田管道结垢腐蚀。

By means of water quality analysis of water-injection system at the Tazhong four oilfield,scaling of the system was divided into two categories.One was mainly owing to the high concentrations of calcium ions bicarbonate radical,which generated calcium carbonate scale.Another one was ferrous sulfide corrosion scaling.Water-injection pipelines of Tazhong fourth oilfield and waterwells of peripheral operation areas contained high sulfide high concentrations.In weak acidic water environment,pipelines with fast flow rate presented less serious corrosion.However,those with slow flow rate or at corners,serious carrion occurred and corrosion scaling of ferrous sulfide generated.In order to reduce the level of scaling effectively,the type of scale inhibitor for calcium carbonate should be the priority.