N80油管钢在CO_2/H_2S水介质中的腐蚀研究

油田设施受产出水和CO2/H2S腐蚀严重.以长庆某天然气井产出水为腐蚀介质,采用失重法研究了不同腐蚀影响因素对N80钢的作用规律.结果表明,随着介质温度的升高,腐蚀速率先增加后降低,并在60℃时达到最大;Cl-的影响与温度具有基本相似的规律,在Cl-含量为30 g/L时腐蚀速率最大;随着pH值的增大,腐蚀速率持续减小,并在pH值为8.0左右时达到最低;随着CO:分压的增大,腐蚀速率呈单调增大趋势;随着H2S分压的增大,腐蚀速率先下降后又缓慢升高.

Factors Affecting the Corrosion Behavior of Tubular Steel N80 in CO_2-and H_2S-Containing Produced Water of Gas Well

Weight loss method was used to investigate the effects of various factors on the corrosion behavior of tubular steel N80 in produced water of a natural gas well in Changqing area. Results show that under the experimental conditions, the corro-sion rate first increased and then decreased with the increase of temperature, and the maximum corrosion rate was recorded at 60 ℃. The effect of Cl- was similar to that of temperature, and the maximum corrosion rate was recorded at a Cl- concentration of 30 g/L. Besides, the corrosion rate constantly decreased with in-creasing pH value and reached a minimum value at a pH value of 8.0. Moreover, the corrosion rate of the tubular steel monoton-ously increased with increasing partial pressure of CO2, but it ini-tially decreased and then slowly increased with increasing partial pressure of H2S.