CO2驱井下缓蚀剂的优选与缓蚀机理研究OA

In response to the severe downhole CO2 corrosion issue associated with high water content during the large-scale exploitation of CO2 flooding in Shengli Oilfield,a novel high-temperature resistant and anti-CO2 corrosion inhibitor was compounded and selected using monomeric corrosion inhibitors,including imidazoline,quaternary ammonium salt,thiourea,alkanolamine,and fatty alcohol.Through testing,the optimal corrosion inhibitor formulation consists primarily of 20%imidazoline+10%quaternary ammonium salt+4%thiourea+10%alcoholamine.Experiments demonstrated that at dosing concentrations above 200 mg/L,corrosion inhibition rates consistently achieved 85%and above,with applicability across varying temperatures,flow rates,and CO2 pressures.Research on the corrosion inhibition mechanism indicated that the adsorption process follows the Langmuir adsorption model,which increases the charge transfer resistance on the metal surface and suppresses the anodic corrosion process,thereby significantly reducing corrosion on the steel surface.Field tests demonstra-ted that at a dosage concentration of 200 mg/L,the downhole corrosion rate can be controlled below 0.076 mm/a,meeting the protection requirements.