The bottom of the cryolithic zone and conditions for the formation of gas hydrates at the T field in the north of West Siberia

The initial data to estimate the gas hydrate stability interval at the T field in West Siberia has been summarized, i.e. the cross-section temperature, reservoir pressure, gas-to-air density, and formation water salinity. The position of the cryolithic zone bottom was modeled by combining the thermal gradient estimated during well testing and the permafrost bottom position based on resistivity logging data. Due to the ambiguity in interpreting the position of the bottom of the permafrost and cryolithic zone, two options of the cryolithic zone bottom maps were built: the minimum and maximum. Thus, two options of the gas hydrate stability zone bottom maps were built: the minimum and maximum. It is shown that the upper gas-saturated reservoirs of the T field are located in the gas hydrate stability zone.