This paper studies empirical and correlation modelling of corrosion test-data for detailing C10H18N2Na2O10 (ethylenediaminetetraacetic disodium salt: EDTA-Na2) performance on concrete steel-rebar corrosion in 3.5% NaCl medium simulating saline/marine environment.

The application of corrosion inhibitors (CI) to producing oil and gas field systems is one of the most common practices of corrosion control. Acid stimulation fluids such as hydrochloric acid (HCl) and organic acids has high calcite and dolomite dissolving power; however, pumping HCl downhole during acid stimulation process particularly at elevated temperatures can cause severe corrosion. Therefore, the addition of corrosion inhibitors is indispensable to protect the metal from corrosion. More inhibitors that are efficacious are still needed to provide better protection against the corrosion.
Two new bisquaternary ammonium salts; 1,4-Benzenedimethanaminium, N,N'-didodecyl-N,N,N',N'-tetramethyl-, dichloride (CI-1) and 1,4-Benzenedimethanaminium, N,N'-dihexadecyl-N,N,N',N'-tetramethyl-, dichloride (CI-2) as corrosion inhibitors were successfully synthesized, characterized and electrochemically evaluated for their corrosion inhibition efficiency in 1 M hydrochloric acid (HCl) solution on API 5L X60 low carbon steel. Potentiodynamic polarization measurement revealed mixed type inhibition mechanisms of the synthesized inhibitors. Inhibition efficiency of CI-1 increase with increase in concentration 2.0 to 20.0 ppm while CI-2 efficiency does not go beyond 2 ppm. Adsorption isotherm of CI-1 was found to deviate from Langmuir isotherm due to its interaction on low carbon steel and the interaction was approximated by Temkin isotherm. Analysis of the adsorption of CI-1 on API 5L X60 involve both physisorption and chemisorption.

Oilfield waters have a complex composition depending on reservoir rock at different geographical locations that can be carried into the production water¹. The alteration in environmental conditions such as pressure, temperature, salt content or pH can cause the liquid to oversaturate and the contained ions to form complexes. These will precipitate out of the solution, deposit and grow on contacting surfaces such as reservoirs, upstream production tubing, sub-surface safety valves, water injection lines to top side refining equipment namely heat exchangers and transport lines ^2–4. Scaling can also be induced by incompatible mixing of fluids. For example CaCO₃ and /or BaSO₄  form through typical mixing of SO4 2- containing sea water with the formation water that carries high concentrations of divalent cations such as Ca²⁺and Ba^2+₂. Similarly, sulfide scales form upon mixing with H₂S-containing  formation water enriched with Fe, Zn or Pb ions ⁵. ZnS and PbS have been observed to form in presence of only 25 ppm H₂S at gulf of Mexico containing 50 ppm Zn and 5 ppm Pb , due to their low solubility constant K_sp ^6,7.