页岩气集输管道腐蚀原因及控制措施

Corrosion Causes and Control Measures of Gathering and Transportation Pipelines for Shale Gas

南川页岩气田管道腐蚀问题逐渐凸显。从管道输送介质和腐蚀产物等方面分析了管道腐蚀的原因,并通过杀菌剂和缓蚀剂室内优选试验和配伍性试验,提出了相关的腐蚀防护措施。结果表明:气质中含有CO_(2),采出水中高含SRB和Cl^(-),腐蚀产物主要由铁、氧、碳等元素组成,CO_(2)、SRB和Cl^(-)的协同作用是造成集输管道腐蚀的主要原因;TK-S01杀菌剂的杀菌效果最好,最佳加注量为100 mg/L,此时其杀菌率达到99.99%;KY-2缓蚀剂的缓蚀效果最好,在最佳加注量150 mg/L条件下,其缓蚀率达到90%;TK-S01杀菌剂和KY-2缓蚀剂的配伍性较好,药剂效果互不影响。

The problem of pipeline corrosion in Nanchuan shale gas field was gradually emerging.The causes of pipeline corrosion were analyzed from the aspects of pipeline transport medium and corrosion products.Through the optimization test and compatibility test in laboratory for bactericides and corrosion inhibitors,relevant corrosion protection measures were put forward.The results show that CO_(2)existed in the shale gas,the produced water contained large number of SRB and Cl^(-),and the corrosion products were mainly composed of Fe,O and C.The synergistic effect of CO_(2),SRB and Cl^(-)was the main reason for the corrosion of pipelines.TK-S01 bactericide had the best bactericidal effect,whose sterilization rate reached 99.99%under the best injection concentration of 100 mg/L.KY-2 inhibitor had the best corrosion inhibition effect,whose inhibition efficiency reached 90%under the best injection concentration of 150 mg/L.The compatibility of TK-S01 bactericide and KY-2 inhibitor was good.There was no interaction on each other.