普光气田N80套管多元腐蚀行为试验研究

Research of N80-Casing Multi-Corrosion Behavior for Puguang Gas Field

普光气田套管腐蚀严重。选择普光气田常见腐蚀离子S2-、Cl-、HCO3-以及温度作为腐蚀影响因素,通过正交试验法,模拟普光气田N80套管钢材在地层水情况下腐蚀行为。结果表明:试验中各因素对试验指标(腐蚀失重率)的影响按大小顺序是NaHCO3质量浓度、温度、Na2S质量浓度、NaCl质量浓度;N80套管材料在不同腐蚀环境下,腐蚀表面形貌各异,多有蚀坑状,少数试样表面有台阶状;腐蚀形态多为点蚀或坑蚀;N80套管材料腐蚀表面产物各不相同,所有腐蚀产物均包括CaCO3、SiO2,部分试样腐蚀产物还包括FeS、KCl,且各腐蚀产物所占质量均不相同。

Abstract. Puguang gas field casing corrosion is serious. The common corrosion,such ion 82 ,C1 , HCOa ,and temperature as corrosion factors in Puguang （;-as Sield are taken for examples by u sing of orthogonal experiment method to simulate the NS0 casing corrosion behavior of the steel in the case of formation water. The results showed that the test of the impact of various factors on the test indicators （rate of corrosion weight loss） in order of NaHCO3 concentration, tempera- ture, Naz S concentration, NaC1 concemration. N80 casing material in a corrosive environment, cor- rosion surface morphology occured in different appearance,mostly in multi pit-like and less sam- ple surface stepwise. The corrosion morphology of pitting or pitting;the corrosion product on N80 surface casing material are not same. All the corrosion products, including CaCOs, SiO2, part of the specimen corrosion products include FeS and KC1, and the occupied quality of product of each corrosion IS not same