油气田H_2S腐蚀体系模拟方法探究

Simulation of Carbon Steel Corrosion in Oil-gas Field Produced Waters Containing Hydrogen Sulfide

通过两种方法向反应釜内引入H2S气体模拟含H2S油气田腐蚀体系:一是使用钢瓶直接通入H2S,二是通过化学反应间接生成H2S。在高压釜内研究了20#钢在这两种不同方法引入H2S体系中腐蚀情况的差异。通过失重法和电化学法研究了两种方法下20#钢的腐蚀速率及腐蚀机理;通过SEM观察腐蚀形貌;并利用EDS分析腐蚀产物的组成。结果表明:20#钢在由化学反应产生H2S模拟油气田环境中的腐蚀速率为0.1077 mm/a,腐蚀产物膜粗糙、疏松。而其在直接导入H2S模拟油气田环境中的腐蚀速率为0.0518 mm/a,腐蚀产物膜均匀、致密、平整,接近现场实际情况。即H2S的导入方法对油气田模拟腐蚀体系的建立有重要的影响。从科学研究角度看,直接通入H2S法能更好地模拟含H2S油气田腐蚀体系。

In order to simulate the carbon steel corrosion in oil-gas field produced water containing H2 S, a proper artificial water was poured into an autoclave and then into which H2 S gas was introduced respectively in two different ways: directly inducing H2 S from a pressed H2 S gas cylinder and generating H2 S gas in-situ during the corrosion process through chemical reaction of desired reagents pre-set in the water. The corrosion rates of 20# steel were comparatively studied for two different ways of introducing H2 S gas, while the other parameters kept the same, by weight loss technique, electrochemical measurement and scanning electron microscopy with energy dispersive spectrometer. It has been found that the 20# steel in the water with in-situ generating H2 S exhibits a corrosion rate 0.1077 mm/a and a coarse and porous corrosion product film. Whereas, those by inducing H2 S from gas cylinder are a corrosion rate 0.0518 mm/a and a uniform and compact corrosion product film respectively. It is also noted that the results of the former one are better accorded with those observed in oil/gas fields practice. Therefore, the way of directly inducing H2 S from gas cylinder into the waters should be suitable to simulate the relevant corrosion performance of metallic materials in oil-gas field produced waters.