In the paper are considered the features of hydrate control during the production of natural and associated petroleum gas from the Yaraktinskoye oil-gas-condensate field, located in the Ust-Kut district of the Irkutsk region. An analysis of the temperature and pressure modes of producing wells is given. It is noted that at the gas and gas condensate fields of Eastern Siberia there are some new features of the process of hydrate formation in the field systems. The hydrate formation conditions were calculated by the component composition of gas, taking into account the influence of methanol and formation saline water. It is shown that the process of hydrate formation is already possible in gas producing wells, which is due to the component composition of natural and associated petroleum gas (the presence of C2-C4 components, which easily form hydrates), high reservoir pressure (up to 25.4 MPa), and relatively low reservoir temperature (37 °C). Beforehand the hydrate formation in the wellbores was not observed during the development of gas condensate deposits in Western Siberia.
A technique for calculating the methanol consumption, taking into account high gas pressures and the possibility of producing formation water by the wells, has been developed. The risks of scaling in the wellbores due to halite precipitation when mixing concentrated methanol with formation water have been analyzed. It is noted that when using aqueous methanol solutions with methanol concentrations at the level of 60-65wt%, there are practically no risks of halite deposition. Technological calculations of the specific methanol consumption of and its aqueous solutions were carried out to prevent hydrate formation, taking into account the risks of scaling associated with high salinity of formation waters of the field. The results obtained make it possible to optimize the technology for hydrate inhibiting by methanol in the wellbores and gas-gathering systems of the Yaraktinskoye field.
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