New «green» inhibitors of gas hydrate formation for the oil and gas industry based on polysaccharides
The thermobaric conditions for the formation of gas hydrates in the presence of the sodium salt of carboxymethylcellulose, dextran, and arabinogalactan were studied in a quasi-equilibrium thermodynamic experiment. It is established that polysaccharides slow down the rate and change the conditions of gas hydrate formation of a mixture of natural gases, showing the properties of a thermodynamic and kinetic inhibitor with technological efficiency exceeding methanol by 170-270 times when used in the same dosages. The results of the development of a «green» synergistic inhibitor of gas hydrate formation «Glycan RU» on their basis are presented, which includes a combination of thermodynamic and kinetic inhibitors. Pilot field tests of «Glycan RU» were carried out at the wells of the Priobskoye, Prirazlomnoye, Ombinsky, Zapadno-Ugutskoye oilfields. It was found that at dosages of 1000 g/m3 and 500 g/m3, there is no formation of hydrate plugs in the annulus. «Glycan RU» is recommended for industrial use by the technology of periodic injection and/or continuous dosing through wellhead dispensers. Keywords: carboxymethylcellulose; dextran; arabinogalactan; polysaccharides; «green» inhibitor of gas hydrate formation; «Glycan RU».