Naphthenic Acid Corrosion Testing
Several set-ups can be used to test crude oils and cuts for naphthenic acid corrosion at high shear stresses (hundreds Pa). The optimal set-up to be used requires that:
- The TAN does not decrease during the test.
- The corrosion inhibitor if used in the test does not decompose and its concentration does not decrease during the test.
- Several specimens can be tested at the same time.
Comparison of Testing Methods for Oil Testing
| Set-Up | Max # of specimens | Amount of Test Fluid (liters) | Once-Through Flow | Re-circulating Fluid | TAN Decrease | Inhibitor Decomposition |
| Rotating cage | 8 or more* | 1 to 4 | No | Yes | Yes | Yes |
| Rotating cage with stopping and fluid replenishment every day | 8 or more* | 12 (4-day run) | No | No | No | No |
| Flow loop with continuous replenishment of rotating cage | 8 or more* | 15 (4-day run) | Yes | No | No | No |
The replenished autoclave and the flow loop look like the best methods for testing high temperature corrosion inhibitors for naphthenic corrosion.
