Corrosion inhibition behavior of MSY-1 inhibitor for downhole tubular goods in CO2/H2S environment

Using high temperature and high pressure hydrogen sulfide corrosion tester, the corrosion behavior of different downhole tubular goods after adding the corrosion inhibitor MSY-1 was studied in the environment containing CO 2 and H2S. The effects of static or dynamic conditions, CO2 and H2S partial pressures on the corrosion inhibiton efficiency were evaluated. The results showed that under the same experimental conditions with CO2/H2S coexisted, the dynamic corrosion rate was higher than the static corrosion rate significantly, the value of the former was about 1. 5∼2 times of that of the latter; 0.02% MSY-1 could reduce the static and dynamic corrosion rates significantly, and the inhibiton efficiency was more than 90%. When CO2/H2S coexisted, the existence of H2S slowed down CO2 corrosion of steels to certain extent, and with increasing H2S partial pressure, the corrosion rate decreased; and with increasing CO2 partial pressure, the corrosion rate increased.