Performance Evaluation And Research On Implantation Technique Of Corrosion Inhibitor For Gathering Pipeline Of CO₂-EOR

Injection of CO₂flooding is an effective technology to enhance oil recovery, but in theprocess of CO₂flooding, gathering lines have been unusually severe corrosion, leading to thedeterioration of the tubing mechanical performance and the lifetime of the equipment cutshort, which has caused enormous economic loss to the oil industry. This thesis for theproblems that the serious corrosion problems of the gathering pipeline and the problems incorrosion inhibitor filling in the process of CO₂flooding, the main research as follows.（1） Under normal temperature and atmospheric pressure, In the oilfield produced fluid with CO₂saturation, using electrochemical method and combining with normal temperature static weight-loss method,18kinds of corrosion inhibitor were studied. Thecorrosion effects were analyzed for5kinds of commonly used oilfield steel. Screeningexcellent corrosion inhibitor for each steel; researches show that：under the normal temperature （20℃） and atmospheric, in the oilfield produced fluid with CO₂saturation,corrosion inhibitors which experiments were involved for N80steel, ZK6825has the best corrosion effect; For20steel, IMC-80-ZS has the best corrosion effect; For Q235steel, IMC-80-BH has the best corrosion effect; For P110, ZK682has the best corrosion effect. For J55steel, RX-1has the best corrosion effect.（2） Using high temperature and high pressure reaction kettle combined with orthogonalexperimental study of20steel （corrosion inhibitor is IMC-80-ZS） and P110steel （corrosioninhibitor is ZK682） under the condition of different corrosion inhibitor concentration,temperature and flow velocity, Different factors were studied for corrosion effect of corrosioninhibitors, observing the corrosion morphology And the study of corrosion mechanism;Experiments show that: for20steel （corrosion inhibitor is IMC-80-ZS）, corrosion effectfactors from main to secondary is Corrosion inhibitor concentrationâ†'temperatureâ†'mediumvelocity. Corrosion inhibitor concentration and medium velocity are the significantinfluencing factors. Corrosion effect is the best under the condition of corrosion inhibitorconcentration is100mg/L, medium velocity is2m/s, and temperature is90℃; For P110steel（corrosion inhibitor is ZK682）, factors affecting corrosion inhibitor corrosion effect frommain to secondary is the corrosion inhibitor concentrationâ†'temperatureâ†'medium velocity.Concentration of corrosion inhibitor is the significant influencing factor; Corrosion effect isthe best under the condition of concentration is150mg/L, medium velocity is1m/s, andtemperature is90℃.（3） For filling course of corrosion inhibitor, Filling volume were studied, the calculationformula of pre-film volume and normal volume injected in injection well and production well. According to different production site conditions, Different corrosion inhibitor filling modesand Technological process are given. and combined with the actual situation of production weput forward the corresponding method of corrosion monitoring.