Causes of accelerated corrosion in coiled tubing during acid washing of a gas field well
摘要
The causes of a coiled tubing NT-95 steel accelerated corrosion after acid washing of the Poltava Basin gas field well were investigated. Corrosion losses of steel in the washing solution do not exceed 3.6 mm/year due to the presence of a corrosion inhibitor in its composition. The corrosion rate of steel increased by three orders of magnitude after acid treatment of a gas well. The accelerated corrosion of steel occurs due to the neutralization of the inhibitor effect and the change in the metal corrosion nature caused by the high concentration of oxidizing agents such as iron (III) Fe2O3 oxides in the well. When Fe2O3 interacts with the hydrochloric acid of the washing solution, iron chloride FeCl3, which partially neutralizes the inhibitor effect and accelerates the corrosion of steel is formed.