Evaluation of the Thermal and Mechanical Interaction of Gas Production Wells with Gas Hydrate Bearing Permafrost

The results of thermal modeling of the interaction of a gas production well with permafrost applied to Bovanenkovo gas-condensate field showed that for 30 years (well lifetime) the thawing halo of permafrost soils can reach 7-10 meters. However, for the interval equipped with vacuum thermal insulation of the lift pipe, there were no permafrost during the entire life cycle of the well, which confirms its high efficiency. Calculations showed that during 30 years of well operation on the Bovanenkovo up to 700 thousand m3 of methane could potentially be released, which is equivalent to a daily emission of up to 70 m3, as a result of gas hydrate bearing permafrost thawing. As a result of the assessment of the mechanical interaction of the gas production well with frozen soils, including permafrost containing relict methane hydrates, it was shown that the settlement of the thawed soils will be up to 3 meters, which will lead to the formation of collapsed crater and cavities with a depth of 4.5-6.5 meters, the volume of which will increase annually to 19 m3. The formed cavities should be considered as a accumulators of methane gas, formed in the process of dissociation of hydrate-containing soils.