Screen And Performance Research On The Efficient Corrosion Inhibitors Used For Gathering System Of C0₂-EOR

CO₂-EOR as a mature oil production technology is worldwide attention. But, all kinds ofpipeline and equipment suffered a severe CO₂corrosion in the exploitation of oil and gas andtransport process, adding inhibitor is generally used to restrain CO₂corrosion measures in theoil and gas field. In order to screen efficient corrosion inhibitors for CO₂-EOR andtransportation system and research their corrosion inhibition mechanism, this thesis mainlyresearch contents: First, under the conditions of normal pressure and temperature, testingefficiency of corrosion inhibitor for the eight kinds of commonly used oil and gas field CO₂corrosion inhibitors in the recovery liquid from Da Qing oil field CO₂-EOR test site. In order toscreen corrosion inhibitors of inhibition efficiency were more than80%; Second, analysingcorrosion inhibition performance of corrosion inhibitors that have been screened and studyingtheir corrosion inhibition mechanism. Finally, to research the corrosion inhibitor performanceof the optimal corrosion inhibitor under the conditions of high temperature and high pressureand dynamic condition, it can provide the theoretical basis for the selection of corrosioninhibitors for oil and gas field and protection of pipe and equipment. Research shows that:（1） Weightless test of in the conditions of normal pressure and temperature found thatcorrosion inhibition rate is more than80%in the concentration of100mg/L, imidazole lincorrosion inhibitors （IMC-80ZS, IMC-80BH）, allylene oxide methyl quaternary ammonium salt（IMC-871W, IMC-871GH1）, corrosion inhibitor is efficient Electrochemical experiments weretested this four kinds of corrosion inhibitors dynamic potential polarization curves andelectrochemical impedance spectroscopy, and also analyzes the corrosion morphology, thefinal determination IMC-871GH1corrosion inhibition effect is the most efficient.（2） The study of corrosion inhibition performance of the allylene oxide methylquaternary ammonium salt IMC-871GH1under high temperature and high pressure in oilrecovery liquid indicates:①There are extremum concentrations under the temperature of30℃,60℃and90℃.As the increase of temperature.the extremum concentration reduces,however, the corrosion rate and corrosion inhibition effect increase;②Under the pressure of0.2MPa,0.4MPa and0.6MPa, the corrosion inhibitors also exist a extremum concentration,theconcentration increases as the pressure increase;③In the ingle-phase flow condition, thecritical velocity of the medium in the oil recovery liquid under60℃,0.2MPa is5m/s, for thesystem with the corrosion inhibitors, the critical velocity of the medium is the function ofcorrosion inhibitors concentration. However, the corrosion inhibition effect reduce as thevelocity increase. Therefore, we should adjust the concentration of the corrosion inhibitorsbase on definite temperature, pressure and velocity conditions etc. For getting the bestcorrosion inhibition effect.