INTRODUCTION
Top of the Line Corrosion (TLC) has been a serious issue for the Oil & Gas industry. Conventional inhibition techniques are expensive and often do not seem to provide enough protection to the steel surface at the top of the pipe. A novel idea is to inject the corrosion inhibitor within a foam matrix. The foam slug is first formed at an injection port and carried along the pipe by the gas phase. This process ensures homogeneous delivery of the inhibitor to the pipe wall along pipe sections suffering from TLC. This paper presents more comprehensive study performed in an innovative glass cell setup which consisted of a foaming cell and a corrosion cell in order to simulate intermittent contact between the foam and the steel surface. Corrosion measurements were performed using electrochemical techniques (EIS, LPR, potentiodynamic sweep) and electrical resistance (ER) measurements, in order to determine the inhibitive performance of investigated inhibitor talloil diethylenetriamine imidazoline (TOFA/DETA imidazoline) within a foam matrix (sodium C14-16 olefin sulfonate).
Top of the Line Corrosion (TLC) can occur in wet gas pipelines where the difference between high inlet temperatures and the cold environment can easily result in water vapor condensation on the cooler surface of the pipe wall at the top of the line.Corrosion appears inside the pipe due to the condensation of water containing dissolved corrosive gases such as CO, CHCOOH, or other short chain acids.Acetic acid or other organic acids which can be present in the gas will dissolve in the water and thereby lower the pH of the condensed water phase and increase the amount of iron which can be dissolved in the condensing water.