Table 2.
Comparison of electrochemical impedance spectroscopy data for AISI 1020 carbon steel in different times of immersion in packer fluid and glyoxal mixtures without and with 500 ppm of polyol phosphate at Ecorr. pH = 7.4, with 2.5 % or 10 % of H3PO4.
| Day | H3PO4 (%) | Cinhibitor (ppm) | Ecorr (mVECS) | Rs(Ω cm2) | Rp (kΩ cm2) | C (μF cm−2) | θ |
|---|---|---|---|---|---|---|---|
| 0 | 0 | -664 ± 10 | 5.1 ± 0.5 | 1.6 ± 0.2 | 59.3 ± 14.2 | ||
| 2.5 | 500 | -656 ± 14 | 5.3 ± 0.5 | 2.2 ± 0.4 | 10.3 ± 1.2 | 0.83 ± 0.01 | |
| 10 | 500 | -460 ± 18 | 5.7 ± 0.2 | 11.2 ± 0.4 | 7.9 ± 1.0 | 0.87 ± 0.01 | |
| 1 | 0 | -644 ± 11 | 5.3 ± 0.7 | 0.7 ± 0.2 | 71.6 ± 18.2 | ||
| 2.5 | 500 | -640 ± 4 | 5.2 ± 0.3 | 2.1 ± 0.4 | 15.3 ± 5.7 | 0.79 ± 0.03 | |
| 10 | 500 | -526 ± 8 | 6.2 ± 0.7 | 10.7 ± 0.8 | 10.3 ± 2.2 | 0.86 ± 0.01 | |
| 7 | 0 | -629 ± 7 | 6.0 ± 1.0 | 0.5 ± 0.2 | 87.5 ± 27.5 | ||
| 2.5 | 500 | -628 ± 5 | 6.8 ± 0.5 | 2.0 ± 0.3 | 17.3 ± 8.7 | 0.80 ± 0.02 | |
| 10 | 500 | -562 ± 10 | 6.4 ± 0.5 | 5.7 ± 0.9 | 12.8 ± 2.4 | 0.85 ± 0.02 | |
| 14 | 0 | -612 ± 4 | 4.7 ± 0.4 | 0.3 ± 0.1 | 108.1 ± 22.6 | ||
| 2.5 | 500 | -611 ± 10 | 6.2 ± 0.6 | 1.6 ± 0.4 | 18.7 ± 5.2 | 0.83 ± 0.01 | |
| 10 | 500 | -581 ± 12 | 6.0 ± 0.4 | 2.4 ± 0.8 | 14.4 ± 3.3 | 0.87 ± 0.01 |