H_(2)S/CO_(2)/O_(2)环境下稠油热采生产井管柱腐蚀机理研究

Study on corrosion mechanism of heavy oil production well string in H_(2)S/CO_(2)/O_(2)environment

为了研究稠油热采生产井管柱腐蚀规律,采用室内挂片失重法实验对影响管柱腐蚀的主要因素进行评价,主要包括温度、H_(2)S分压、CO_(2)分压及O_(2)分压,并通过分析腐蚀产物厘清腐蚀机理。实验结果表明,P110钢的腐蚀产物主要是FeCO_(3)、FeS和Fe_(2)O_(3),当温度低于70℃时,腐蚀速率随着温度的升高而增大,70℃时达到最大值,随后开始减小;CO_(2)、O_(2)分压增大,腐蚀速率增大,H_(2)S分压增大,腐蚀速率先减小后增大。通过各因素对腐蚀速率的影响结果对比可知,O_(2)分压和温度对腐蚀速率的影响要高于H_(2)S和CO_(2)。腐蚀规律和机理对保障安全生产和提高管柱使用寿命具有重要意义。

In order to study the corrosion law of heavy oil production well string,the main factors affecting the corrosion of pipe string were evaluated by weight loss test in laboratory,including temperature,H_(2)S partial pressure,CO_(2)partial pressure and O_(2)partial pressure,the corrosion mechanism is clarified by analyzing the corrosion products.The results show that the main corrosion products of P110 steel are FeCO_(3),FeS and Fe_(2)O_(3).When the temperature is less than 70℃,the corrosion rate increases with the increase of temperature,and reaches the maximum at 70℃,then begins to decrease.With the increase of CO_(2)and O_(2)partial pressure,the corrosion rate and H_(2)S partial pressure increased,and the corrosion rate first decreased and then increased.The results show that the effect of oxygen partial pressure and temperature on corrosion rate is higher than that of H_(2)S and CO_(2).The corrosion law and mechanism are of great significance for ensuring the safety of production and increasing the service life of pipe string.