Grey correlation analysis for the corrosion factors of injection system of air foam flooding

Serious oil well tubing corrosion problem generally exists in the operational process of air foam flooding technology and needs to take the effective control measures to prolong the pipeline life and guarantee safe oilfield production with low cost.Therefore, the corrosion factors for the injection system of air foam flooding were analyzed thoroughly.By using laboratory specimen weight loss method, the influence law of corrosion rate affected by injection casing corrosion factors was studied, and on this basis, by using grey correlation methods, the grey correlation degree of corrosion rate by various corrosion factors was calculated and sequenced according to its influence degree.The results show that the corrosion rate of the casing becomes higher with the increase of air/ foam alternating injection frequency, foam liquid flow velocity, air parameters (including oxygen content, humidity, temperature and pressure) and the grey correlation degree sequence is air/foam liquid alternation frequency > oxygen concentration in the air > temperature > humidity > flow velocity of the foam liquid.The research results offer reference for further comprehending the corrosion mechanism of air foam flooding and making relevant control countermeasures.