Kinetic Hydrate Inhibitor Removal by Physical, Chemical and Biological Processes Available to Purchase

Hydrate formation is a major flow assurance issue in the production of oil and gas fields. Kinetic hydrate inhibitors (KHI) act as anti-nucleating agents and delay the formation of gas hydrates. These chemicals are more economical than the thermodynamic inhibitors and are added at a low dosage without disturbing the pipeline flow. Globally, different proprietary KHI compounds are used; one type of KHI was investigated in the present work. Considering that produced water containing KHI may have negative impact on the environment and reservoir permeability, efficient treatment solutions to remove KHI are needed. The objective of our investigation was to assess various physical, chemical and biological treatment methods for KHI removal. These methods included membranes, heated centrifugation, advanced oxidation and membrane bioreactors. On a lab scale, KHI removal efficiencies were > 99.9 % and 83% for nanofiltration and ultrafiltration respectively. Heated centrifugation removed 40% and oxidation degraded more than 70% of KHI polymer. Biotreatment efficiently degraded about 70% of KHI when added at 1.5% to brine. To check the effectiveness of each process, the treated KHI solutions were eluted through crushed Sulaiy core for deposition/interaction studies. Three criteria were used to verify the effect on the treated effluent: cloud point, particle size and interaction with the crushed core. The desired values for the treated effluent included a cloud point > 65ºC, a particle size less than 0.5 micron, and a retention magnitude of less than 10% of the polymer on the crushed core. To the authors' knowledge, this is the first work reported in the literature regarding KHI removal using some of these processes. The treatment processes have great potential when implemented by the oil & gas industry for environmental and operational sustainability.