EFFECT OF THE MIXTURE OF CORROSION AND SCALING INHIBITORS ON PROTECTION AGAINST CORROSION OF CARBON STEEL

The advances of the new technologies in order to explore and produce oil and gas in deep and ultra-deep water is followed with challenges related to corrosion and scaling issues in production and injection wells. in the same way, scaling control in production wells due to carbonate deposition is one of the innumerous challenges of the Brazilian Pre salt. scaling leads to flow restriction and erosion problems in addition corrosion problems which may lead to a production decrease. One of the procedures adopted for removal and scaling inhibition is using inorganic (HCl) or organic (acetic acid) acids, however, the use of these ones is done by the presence of corrosion inhibitors in high level concentration which have high costs. Chelates, such as EDTA, can be used as alternatives in oil and gas wells both in stimulation operations and for the prevention and removal of scales. This work aims to study the effect of the mixture of two kinds of compounds (corrosion and scaling inhibitors) on carbon steel protection by mass loss measurements, electrochemical tests and qualitative scaling test. it was verified an increasing of the corrosion rate of carbon steel by the presence of EDTA, which was reduced by the addition of both anticorrosive and antiscaling compounds