CO_(2)复合汽驱工艺管道的选材研究

Study on the Material Selection of Pipeline in Steam-CO_(2) Combination Flooding Process

针对CO_(2)复合汽驱工艺的特点,研究地面集输工艺管道材料的适用性。采用理化检验、高温高压釜浸泡、腐蚀产物分析等方法,对碳钢(20和L245NS)和不锈钢(304L和316L)开展相关试验研究。结果显示:在温度100℃、总压0.6 MPa、CO_(2)气体含量0.48 MPa、H 2 S气体含量0.0012 MPa条件下,2种碳钢均腐蚀明显,表面附着了一层聚集性颗粒状的腐蚀产物,腐蚀产物的主要元素组成为C、O、S、Cl和Fe,物相主要组成为FeS和FeCO_(3),腐蚀程度为严重程度;而2种不锈钢腐蚀轻微,表面腐蚀产物较少,腐蚀程度为轻度。建议CO_(2)复合汽驱工艺管道优先选用304L或316L不锈钢,若要选择20钢或L245NS等碳钢时需配套加注缓蚀剂,且缓蚀率达到70%以上。

According to the characteristics of steam-CO_(2)combination flooding process,the applicability of pipeline materials for ground gathering and transportation process was studied.By means of physical and chemical examination,high temperature autoclave immersion and corrosion product analysis,the related tests were carried out on carbon steel(20 and L245NS)and stainless steel(304L and 316L).Results showed that under the temperature of 100℃,the total pressure of 0.6 MPa,partial pressure of CO_(2)gas of 0.4800 MPa and partial pressure of H 2 S gas of 0.0012 MPa,significant corrosions occurred in two carbon steels.The surfaces of two carbon steels were attached to a layer of aggregated granular corrosion products,the main elements of which were C,O,S,Cl and Fe,and the main phase was FeS and FeCO_(3)with serious corrosion degree.In comparison,the corrosion of two stainless steels was slight,and there were very few corrosion products on their surface,indicating the corrosion degree was slight.Therefore,it was suggested that 304L or 316L stainless steel should be preferred for pipeline in steam-CO_(2)combination flooding process.When 20 or L245NS carbon steel were selected,several corrosion inhibitors should be added and the corrosion inhibition rate could each more than 70%.