Release:2018, Vol. 4. №2
About the authors:Nelli F. Chistyakova, Dr. Sci. (Geol.-Mineral.), Professor, Department of Mechanics of Multiphase Systems, University of Tyumen; firstname.lastname@example.org
This article assesses the features of the current state of permafrost in the west of the industrial development of the Bovanenkovo field according to the analysis of the physical, chemical, and lithologic-facies characteristics of the Cenozoic deposits. The current state and lithological composition of permafrost rocks of the Bovanenkovo uplift (to which the Bovanenkovo oil and gas field is confined in the absolute range between +10 and −330 m) is characterized by stratification and spatial variability. The non-stationary temperature field of this permafrost rocks (which depends on natural and anthropogenic factors) is characterized by changes in the depth and forms of the 0°C isotherm lying in the lower part of permafrost between cooled and thawed rocks and an isotherm of −5°C, isolated in the roof of frozen rocks at the boundary with a seasonal layer of freezing-thawing. Changes in the depth and shape of the 0°C isotherm are influenced by natural factors; and the isotherm −5°C is a complex effect of natural and anthropogenic factors. The presence of two zones of phase transitions of water of different capacities is established: the upper one — in the zone of the seasonal freezing-thawing layer, the lower one — at the contact of the layer of cooled and thawed rocks. Taking into account the specific features of the current state of permafrost (temperature, depth, form of the 0°C, −5°C isotherms, and the capacity of the frozen and cooled rock layers along the Bovanenkovo uplift), the modified and unchanged permafrost rocks are distinguished.