A Novel Method to Mitigate the Top-of-the-Line Corrosion in Wet Gas Pipelines by Corrosion Inhibitor within a Foam Matrix

Abstract

Top-of-the-line corrosion (TLC) has been a serious issue for the oil and 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 formed first 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 a comprehensive study performed in an innovative glass cell setup which consisted of a foaming cell and a corrosion cell to simulate intermittent contact between the foam and the steel surface. Corrosion measurements were performed using electrochemical techniques (electrochemical impedance spectroscopy [EIS], linear polarization resistance [LPR], potentiodynamic sweep) and electrical resistance (ER) measurements to determine the inhibitive performance of investigated inhibitor talloil diethylenetriamine imidazoline (TOFA/DETA imidazoline) within a foam matrix (sodium C14-16 olefin sulfonate).

Electrochemistry of carbon dioxide corrosion mitigation using tall oil diethylenetriamine imidazoline as corrosion inhibitor for mild steel

“…Imidazoline‐based corrosion inhibitors are cationic surface active compounds widely used for protecting pipelines from CO 2 corrosion in the oil and gas industry . The surfactants have an affinity to accumulate at the interface of immiscible fluids resulting in a corresponding lowering of the interfacial tension.…”

Corrosion problems and solutions in oil, gas, refining and petrochemical industry

“…There is a critical rate of condensation of water vapor in gas pipelines (0.15 to 0.25 ml m -2 s -1 ) for appearing top-of-line corrosion [20]. Various models were developed that allow to predict corrosion rates of carbon steel knowing condensation rate of water vapor and other parameters [21][22][23][24][25][26][27]. Ultra sound examination with flexible sensors is used for determination top-ofline corrosion [28].…”

“…Inhibitors are not always able to prevent corrosion at the top of the pipelines. Volatile corrosion inhibitors [62] and inhibitors that are introduced into the foam matrix [27] are recommended in these cases. Inhibitors produce a thin layer of molecules on the surface of the metal.…”

Development of an effective method for internal pipeline corrosion control in the presence of CO2

“…Corrosion inhibitors contain different functional groups, usually polar head (fatty acids, amines, imidazolines, oxygen, sulphur or phosphorus containing species, quaternary amines) and long hydrocarbon chain (typically C14-C18), which promote the binding of inhibitor molecules to the metal surface [12][13][14][15][16][17]. Imidazoline based corrosion inhibitors are cationic surface active compounds widely used for protecting pipelines from CO 2 corrosion in the oil and gas industry [18][19][20][21].…”