| LIN Hai,XU Jie,XING Xue-song,FAN Bai-tao,YANG Jin,WANG Xiao-peng.Corrosion Behavior of L80 Tubing Steel in CO2/H2S Environment[J],45(5):84-90 |
| Corrosion Behavior of L80 Tubing Steel in CO2/H2S Environment |
| Received:January 19, 2016 Revised:May 20, 2016 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2016.05.013 |
| KeyWord:L80 tubing steel CO2/H2S corrosion corrosion product corrosion rate corrosion morphology influencing factors |
| Author | Institution |
| LIN Hai |
CNOOC China Limited, Tianjin Branch, Tianjin , China |
| XU Jie |
CNOOC China Limited, Tianjin Branch, Tianjin , China |
| XING Xue-song |
CNOOC China Limited, Tianjin Branch, Tianjin , China |
| FAN Bai-tao |
CNOOC China Limited, Tianjin Branch, Tianjin , China |
| YANG Jin |
Department of Petroleum Engineering, China University of Petroleum, Beijing , China |
| WANG Xiao-peng |
CNOOC China Limited, Tianjin Branch, Tianjin , China |
|
| Hits: |
| Download times: |
| Abstract: |
| Objective To study the corrosion behavior of L80 tubing in CO2/H2S environment. Methods Scanning electron microscopy (SEM) and EDAX energy spectrum were used to analyze appearance characteristics and chemical compositions of corrosion products, and simulation experiment was conducted using HTHP autoclave and actual water sample after oil/water separation as the corrosive medium, to study the influence law of water cut, CO2/H2S partial pressure and temperature on L80 tubing corrosion rate. Results In CO2/H2S environment, L80 tubing inwall had obvious local corrosion characteristics, the depth of pitting corrosion in part area was more than 100 μm， and corrosion products such as FeS,FeCO3 were formed. With the increase of water cut, the corrosion rate of L80 tubing gradually increased, the corrosion rate was 0.0377 mm/a when water cut was 30%, the corrosion rate was 0.0952 mm/a when water cut was 100%. When the CO2 partial pressure was constant, with the increase of H2S partial pressure, L80 steel corrosion rate increased; the corrosion rate was 0.0377 mm/a when H2S partial pressure was 0.04 MPa; the corrosion rate was 0.0952 mm/a when H2S partial pressure was 0.3 MPa. When the H2S partial pressure was constant, with increasing CO2 partial pressure, the corrosion rate of L80 steel did not significantly change, and the corrosion rate was smaller. With increasing temperature, the corrosion rate firstly significantly increased, and then decreased with a smaller amplitude. The corrosion rate changed from 0.0083 mm/a to 0.1264 mm/a when the temperature increased from 40 ℃ to 100 ℃, and the corrosion rate was the largest at about 100 ℃. The corrosion rate was 0.106 mm/a when the temperature was 120 ℃. Conclusion L80 tubing had mainly uniform and local corrosion in CO2/H2S environment. The corrosion rate of L80 tubing was more sensitive to H2S partial pressure than CO2 partial pressure. Good FeCO3 protective film was formed when CO2 partial pressure increased, reducing the corrosion rate. When the temperature increased to a certain range, the solubility of carbonate and other slightly soluble salts was reduced, forming a protective layer on steel surface to decrease the corrosion rate. |
| Close |
|
|
|