The most important and promising direction in the Russian oil and gas industry is the development of the Arctic shelf, the largest in the world. Today, in the case of the development of oil and gas deposits remote from the coast, the use of underwater pipelines is not only unprofitable, but also technically unfeasible due to the short summer navigation. A problem arises when mastering the delivery of energy carriers to the industrial regions of Russia, as well as for export. One of the ways to solve this problem is the use of underwater reservoirs as a means of temporary accumulation of the product. During the operation of underwater oil storage facilities, situations may arise that lead to dome deformation. To prevent such negative consequences, a reliable prediction of the stress-strain state is required. In this paper, the authors considered the modeling of the stress-strain state of the welded joint of the wall-to-bottom of the tank, as well as the zone of monolithic steel dome of the body in concrete. The depth of 100 m for the installation of an underwater storage was chosen due to the presence of hummocks in the seas of the Russian Arctic, which can affect the seabed to a depth of 15–40 m, as well as icebergs — up to 80 m. The authors developed a numerical axisymmetric finite element model of an underwater storage section, which allows to determine the stress distribution in the domed part of the tank, as well as in the foundation, in accordance with all the features of the underwater tank. The calculations showed that for the considered operating conditions of the deposits, the use of sheets of high-strength steel D690W with a thickness of 50 mm is not enough to ensure the stability of the structure, since stresses arise in the weld that exceed the yield strength of the selected steel. Therefore, it is required either to reduce the immersion depth of the storage, or to provide for a greater thickness of the domed part of the body with the use of ribs that increase the rigidity and stability of the structure.

This paper attempts to determine the law of motion of a tank as a large volumetric massive structure when immersed in a resisting liquid medium. The authors propose two methods for its determination. Dependence graphs of coordinates, speed, acceleration of the tank versus time are plotted. The dependence of time and speed of lowering of a massive storage structure on the volume of pumped water is determined. In addition, the range of the optimal volume of water pumped inside the tank for the purpose of its soft landing is determined.

The article presents the current disadvantages of onshore LNG tanks used in the Arctic. A critical analysis of the closest analogue – a floating LNG storage of gravity type - was carried out. On the basis of the results of the critical analysis a completely new design of an underwater LNG storage was offered. Also the principles of submergence and exploitation of the storage were described. The conclusion about the opportunity of application of underwater tank farms was made.

There was proposed a compact underwater energy generating device in which energy is produced by underwater currents and tidal phenomena on the Arctic coast for small settlements. These communities will be created to track ships sailing along the Northern Sea Route and to provide operational assistance if necessary. The idea of the technical proposal is structurally distinctive, the device is carried out of a set of conventional pipes of a certain diameter with a fairly wide bell (funnel), horizontally mounted towards the underwater current. This idea is quietly new for Russia, and it’s learned not very well. Calculation was provided in a new way on the basis of Propellers theory. In result there are shown table with calculated efficiency of our turbines with defined quantity of turbines in machine unit. Also we suppose that our approach is more accurate then results obtained with Betz’s formula as so as Betz’s formula doesn’t consider geometrical option of impeller.