Composite Barrier to Control the Corrosion of Mild Steel in Oil Well

Mild steel is a very important engineering metal. Petrochemical industries are used bulk amount for their various purposes like recovery of crude oil, refinery units and transportation. Crude oil is a very highly viscous liquid for the opening of the month well strong HCl acid and saline water is used. They produce hostile environment of mild steel. Gaseous substances like CO2 and SO2 gases are found into the well of petroleum. Large amount of saline water are used during recovery of crude oil in this water CO2 and SO2 are dissolved to produce H2CO3 and H2SO4. These acids create an acidic medium of mild steel. Saline waters have possessed Cl¯ ions. It produces ambient environment for mild steel. The solution of salty water contains dissolve oxygen which develop corrosive environment of mild steel. These major corrosive substances are available during recovery of crude oil and they form corrosion cell with base metal. Metal produces galvanic, pitting, stress, crevice, intergranular corrosion. Nanocaoting and filler methods are used to protect metal in such un-friendly environment. The corrosion rate of metal was calculated by weight loss experiment in absence and presence of nanocoating and filler materials. The synthesized organic compound octahydrodibenzo[a,d][8]annulene-5,12-dihydrazone is applied for nanocoating and MgS as filler. The coating and filling works were completed by chemical vapour deposition and nozzle spray method. Potentiostat used for determination corrosion potential and corrosion current density. The surface adsorption was studied by thermal parameters like activation energy, heat of adsorption, free energy, enthalpy and entropy. The thermal parameters results were shown that coating and filler compounds were adhered with base metal by chemical bonding. The thermal results were calculated by Arrhenius equation and Langmuir isotherm. The coating and the filler substance formed composite barrier with metal and developed a protective barrier for the corrosive substances.