Kinetic Inhibition Effect of Valine on Methane Hydrate Nucleation Time in Oil System

Abstract

Amino acids are known as novel kinetic hydrate inhibitor (KHI) for hydrate mitigation, however, the performance in oil system is not well justified up to date. In this study, the kinetics of methane hydrates in oil dominated systems using valine amino acid has been studied in a high-pressure gas hydrate reactor at 80 bar and 1 °C using the constant cooling method. Drilling oil was used in this work to mimic the oil phase in flow assurance. The results shows that valine delays hydrate formation nucleation time 4 times compared with pure water systems. This finding is contrary to most claims in literature that shows that valine promotes hydrate in gas dominated system. However, the inhibition impact of valine exhibited in this work might be due to the presence of oil with is absence in the most literature studies. The findings in the work are useful for hydrate mitigation using amino acids in flow assurance.

Kinetic and Thermodynamic Influence of NaCl on Methane Hydrate in an Oil-Dominated System

“…In the cell interior, a 500 rpm motor is used to ensure sufficient sample agitation within the testing cell under designed conditions. The cell is submerged in a thermostatic bath using ethanol as a coolant, equipped with a PID controller for controlling the bath temperature. , A gas booster compressor injects methane into the cell, and 100 mL of NaCl and oil solutions manually load 50 mL of oil and 50 mL of NaCl solutions into the cell. Figure shows the apparatus and schematic diagram that is linked to a data acquisition system that continuously logs the pressure and temperature inside the cell every 5 s with a precision of ±0.01 MPa and ±0.1 K.…”