Study On Corrosion Control Inhibitors For Natural Gas Wells In Yanchang Exploration Area

Aiming at the characteristics of corrosion medium in natural gas wells in Yanchang exploration area,Imidazoline Corrosion Inhibitors and imidazoline quaternary ammonium salt corrosion inhibitors were synthesized.Three factors and three levels L₉?3⁴?were selected to design orthogonal experiments,27 different imidazoline compound corrosion inhibitors and 27 imidazoline quaternary ammonium salt compound corrosion inhibitors were prepared,and their water solubility was evaluated.The results showed that 54 kinds of compound corrosion inhibitors met the field application requirements with fine dispersion.54 kinds of composite inhibitors were evaluated by static hanging patch and dynamic hanging rod.The results showed that FMJ1,a quaternary ammonium salt inhibitor of imidazoline oleate,had better corrosion inhibition effect,with a inhibition rate of 90.43%;FMJ2,a quaternary ammonium salt of imidazoline naphthenate,had better corrosion inhibition effect,with a inhibition rate of89.29%;and FMJ3,a quaternary ammonium salt of imidazoline adipate,with a corrosion inhibition rate of 90.19%.In a comprehensive comparison,FMJ1,with lower economic cost,was selected as corrosion control inhibitor for natural gas wells in Yanchang exploration area.The proportion of FMJ1 inhibitor was 15%oleic acid imidazoline quaternary ammonium salt,5%thiourea,10%Urotrope,10%OP-10 surfactant,10%1227 surfactant,30%anhydrous ethanol and 25%distilled water.The concentration of the inhibitor is 150 mg/L.The inhibitor has favorable corrosion inhibition and economic effect.