Structural changes in the economy of the Northern zone in the modern period

The aim of the work was to study and evaluate structural changes in the economy of the regions of the North at the present stage of their development (in the period from 2015 to 2019). On the basis of the methodology previously developed by the author for assessing structural shifts, twenty types of economic activity were grouped into two large spheres: production and non-production (services), each consisting of four combined industries. For these economic spheres and industries, an assessment of sectoral and then territorial structural shifts in the period 2015–2019 was carried out. It was found that in the structure of the economy of the regions of the North during this period, the vector of development changed towards an increase in the share of the production sector and a decrease in the non-production sector by 4,4 %, whereas in the previous period 2005–2015, the opposite picture was observed. The high rates of development of the production sector in all regions of the North were revealed, while it grew most rapidly in the West Siberian region due to the extensive development of new gas fields and the construction of new largest LNG complex in the North on the Yamal Peninsula. As a result, the share of GRP in the Northern zone increased in the country from 13,2 % in 2015 to 14,5 % in 2019, and the pace of development was outstripping: 144,6 % versus 129,2 % in the Russian Federation. It is noted that the pace and volume of both sectoral and territorial structural shifts in the production sector in almost all regions of the North zone are almost entirely related to both the scale of investments directed to the development of their economy and the current situation for their resources in the world commodity markets.

Construction of a Multipurpose Exploration Well in the Jurassic Deposits Subsequent Transfer to Production Enabled by Metal Expandable Barrier Installed Behind the Casing

Summary The resource base of the north of the West Siberian oil and gas province is the basis of Russia's energy strategy. Among the northern territories of the province, the Nadym-Purskaya, Pur-Tazovskaya and Yamal oil and gas regions (OGRs) are the leaders in terms of estimated gas reserves (Figure 1). However, the largest deposits of the first two OGRs are in the stage of falling production. Therefore, the main prospects should be associated with the Yamal OGR, which has not yet been put into active operation. It is logical that along with the development of traditional methods of extraction of "dry" natural gas, the government of the Russian Federation has approved a plan for the production of liquefied natural gas based on the fields of the Yamal Peninsula, which is currently being actively implemented by PJSC "NOVATEK". (https://www.novatek.rU/m/business/exploration/)

Comprehensive Assessment and Targeted Approach to the Implementation of the Gas-Lift Method of Operation on the Yamal Peninsula Novy Port Field

As geological environment becomes more complicated, specifics of oil fields with high gas content more demanding, and the Company's requirements for assets development efficiency more stringent, new challenges arise that require application of high-tech approaches and new tools to solve the tasks set. The era of "easy" oil is far behind, and there are no "simple" tasks left, so the key goal of oil companies now is to radically improve efficiency of existing "difficult" fields including development of gas condensate reservoirs and oil rims. The interest in development of new approaches to improve efficiency of the Novoportovskoye field is caused by the huge potential of the asset. Despite the fact that the field was discovered back in 1964, its remaining reserves are estimated at more than 250 million tons of oil and gas condensate and more than 270 billion cubic meters of natural gas, which are concentrated in five reservoirs. The Novoportovskoye field is the northernmost and largest on the Yamal Peninsula, but the complexity of its development and operation is caused not so much by geography and the lack of transport infrastructure but by the presence of a gas cap, low reservoir permeability, the occurrence of underlying water, and high gas content in produced reservoir fluid. The high gas content complicates the production process. The main method of operation in the existing fields of the Yamal Peninsula is artificial lift by electric submersible pumps (ESP) on rental basis. Given the remoteness and isolation of the Arctic region, the high cost of equipment rental, and the low efficiency of ESPs in liquids with high content of dissolved gas, it is only fair to ask a question of whether there is a tool that may allow us to predict operation parameters for different lift methods. The existing models and tools intended to assess behavior of the field are not good enough to fully predict gas breakthrough rates, optimize well operation parameters in case of short-term production forecasting, or select the optimal lift method. In this paper, we described application of an integrated modeling process for a targeted assessment of well operation parameters at the Novoportovskoye field. Also, in the framework of this paper, we performed a technical and economic estimation of the options under consideration, and formulated some recommendations to improve efficiency of development and operation of the field under the impact of the existing complicating factors.

FEATURES OF THE RADIAL GROWTH OF SHRUBS BETULA NANA AND SALIX LANATA ON VARIOUS LANDSCAPE ELEMENTS IN THE SOUTHERN TUNDRA OF YAMAL

Tundra communities are widespread in the northern part of Russia, in particular on the Yamal Peninsula in the registration of Siberia, where research was carried out. For the study, we used plants of the species Betula nana and Salix lanata, these species are among the most common in the southern tundra of Yamal. Sampling sites were located on various morphological elements of the relief with the identification of patterns in the distribution of natural resources that determine the radial growth of the trunks of Betula nana and Salix lanata. At each site, at least 30 samples of each species were taken to obtain a sufficient sample. The sampling sites were located on different morpholog-ical parts of the relief. In the course of the study, general growth trends are highlighted, as well as absolute values of growth for 5 years. This age corresponds to the minimum age of the selected plants. As a result, data were obtained on the distribution and growth characteristics of Betula nana and Salix lanata shrubs along the relief profile; the most and least favourable areas of the profile for the growth of shrubs were identified. To compare the general trends of radial growth, a faster slowdown in growth was found in Betula nana. In addition, it was found that the species Salix lanata has a stronger effect on mechanical impact (winter road).

Formation of Gas-Emission Craters in Northern West Siberia: Shallow Controls

Gas-emission craters discovered in northern West Siberia may arise under a specific combination of shallow and deep-seated permafrost conditions. A formation model for such craters is suggested based on cryological and geological data from the Yamal Peninsula, where shallow permafrost encloses thick ground ice and lenses of intra- and subpermafrost saline cold water (cryopegs). Additionally, the permafrost in the area is highly saturated with gas and stores large accumulations of hydrocarbons that release gas-water fluids rising to the surface through faulted and fractured crusts. Gas emission craters in the Arctic can form in the presence of gas-filled cavities in ground ice caused by climate warming, rich sources of gas that can migrate and accumulate under pressure in the cavities, intrapermafrost gas-water fluids that circulate more rapidly in degrading permafrost, or weak permafrost caps over gas pools.

Climatic Factors Influencing the Anthrax Outbreak of 2016 in Siberia, Russia

In 2016, an outbreak of anthrax killing thousands of reindeer and affecting dozens of humans occurred on the Yamal peninsula, Northwest Siberia, after 70 years of epidemiological situation without outbreaks. The trigger of the outbreak has been ascribed to the activation of spores due to permafrost thaw that was accelerated during the summer heat wave. The focus of our study is on the dynamics of local environmental factors in connection with the observed anthrax revival. We show that permafrost was thawing rapidly for already 6 years before the outbreak. During 2011–2016, relatively warm years were followed by cold years with a thick snow cover, preventing freezing of the soil. Furthermore, the spread of anthrax was likely intensified by an extremely dry summer of 2016. Concurrent with the long-term decreasing trend in the regional annual precipitation, the rainfall in July 2016 was less than 10% of its 30-year mean value. We conclude that epidemiological situation of anthrax in the previously contaminated Arctic regions requires monitoring of climatic factors such as warming and precipitation extremes.

Permanent Gas Emission from the Seyakha Crater of Gas Blowout, Yamal Peninsula, Russian Arctic

The article is devoted to the four-year (2017–2020) monitoring of gas emissions from the bottom of the Seyakha Crater, located in the central part of the Yamal Peninsula (north of Western Siberia). The crater was formed on 28 June 2017 due to a powerful blowout, self-ignition and explosion of gas (mainly methane) at the site of a heaving mound in the river channel. On the basis of a comprehensive analysis of expeditionary geological and geophysical data (a set of geophysical equipment, including echo sounders and GPR was used) and remote sensing data (from space and with the use of UAVs), the continuing nature of the gas emissions from the bottom of the crater was proven. It was revealed that the area of gas seeps in 2019 and 2020 increased by about 10 times compared to 2017 and 2018. Gas in the cryolithosphere of the Arctic exists in free and hydrated states, has a predominantly methane composition, whereas this methane is of a biochemical, thermogenic and/or mixed type. It was concluded that the cryolithosphere of Yamal has a high level of gas saturation and is an almost inexhaustible unconventional source of energy resources for the serving of local needs.

Accessory and Ore Mineralization of Schists from the Basement of the Yamal Peninsula (Zapadno-Yarotinsky Area, Western Siberia)

The results of studying the mineralogy of metamorphic schists from the Pre-Jurassic base of the Arctic part of the West Siberian plate are presented. The accessory and ore mineralization of schists from the Zapadno-Yarotinsky license area located in the southern part of the Yamal Peninsula is studied. The schists was uncovered by the Zapadno-Yarotinskaya No. 300 well at a depth of 2762 m. Above the section, the metamorphic rocks are overlain by a young Meso-Cenozoic cover. The schists are mainly composed of quartz, plagioclase (albite), carbonates (dolomite and siderite), mica (muscovite) and chlorite (donbassite). The discovered accessory and ore minerals in the metamorphic schists of the Zapadno-Yarotinsky area can be divided into two groups. The first group includes minerals that were formed during the metamorphism of schists, or were preserved as detrital matter. These minerals include zircon, fluorapatite, and rutile as the most stable compounds. The remaining mineralization (pyrite, sphalerite, chalcopyrite, cubanite, galena, cobaltite, barite, xenotime-(Y), goyazite, synchysite-(Nd), native silver and copper) is clearly secondary and was formed as a result of superimposed metasomatic processes. Judging from the described mineralogy, the schists underwent changes as a result of superimposed propyllitization. The temperature range of this process is determined by the formation of cubanite in association with chalcopyrite at a temperature of 200-210 оС.

Change of feed stocks in southern subarctic tundra of Yamal

The relevance of the research is related to the need to monitor the resource potential of the vegetation in the southern subarctic tundra. The Yamal tundra has been experiencing a high grazing pressure since 1990. As a result of the increase in the number of private farms and the number of domesticated reindeer in Yamal, pasture degradation occurs (trampling of forage mass, shredding vegetation, disappearance of lichen cover, increased soil deflation). Purpose of the research is compare the forage stocks of reindeer pastures in the southern subarctic tundra of Yamal in 2017–2018 and in the 1990s. In the course of the study, estimates of the amount and structure of forage stocks in plant communities of the southern subarctic tundra of the Yamal Peninsula was assessed in the vicinity of the Payutayakha river. The stock of aboveground phytomass was determined by the mowing method. In 2017, degraded areas of the tundra were studied, and in 2018 undisturbed and intact areas were investigated. Scientific novelty. The data obtained are compared with the estimates published for the southern subarctic tundra in the 1990s. Results. Forage stocks in degraded areas, compared to stocks in the southern subarctic tundra in the 1990s, decreased 14 times; while in on undisturbed areas they decreased 3 times. In the structure of forage stocks in 2017–2018, compared to the situation at the end of the 20th century, the proportions of shrubs, lichens and grasses has decreased; the proportion of dwarf shrubs in degraded areas increased 4 times, while in undisturbed areas it increased 6 times. The study confirms the existence of overgrazing and a shortage of forage resources on pastures in the zone of the southern subarctic tundra of Yamal.

Mapping Arctic Lake Ice Backscatter Anomalies Using Sentinel-1 Time Series on Google Earth Engine

Seepage of geological methane through sediments of Arctic lakes might contribute conceivably to the atmospheric methane budget. However, the abundance and precise locations of such seeps are poorly quantified. For Lake Neyto, one of the largest lakes on the Yamal Peninsula in Northwestern Siberia, temporally expanding regions of anomalously low backscatter in C-band SAR imagery acquired in late winter and spring have been suggested to be related to seepage of methane from hydrocarbon reservoirs. However, this hypothesis has not been verified using in-situ observations so far. Similar anomalies have also been identified for other lakes on Yamal, but it is still uncertain whether or how many of them are related to methane seepage. This study aimed to document similar lake ice backscatter anomalies on a regional scale over four study regions (the Yamal Peninsula and Tazovskiy Peninsulas; the Lena Delta in Russia; the National Petroleum Reserve Alaska) during different years using a time series based approach on Google Earth Engine (GEE) that quantifies changes of σ0 from the Sentinel-1 C-band SAR sensor over time. An algorithm for assessing the coverage that takes the number of acquisitions and maximum time between acquisitions into account is presented, and differences between the main operating modes of Sentinel-1 are evaluated. Results show that better coverage can be achieved in extra wide swath (EW) mode, but interferometric wide swath (IW) mode data could be useful for smaller study areas and to substantiate EW results. A classification of anomalies on Lake Neyto from EW Δσ0 images derived from GEE showed good agreement with the classification presented in a previous study. Automatic threshold-based per-lake counting of years where anomalies occurred was tested, but a number of issues related to this approach were identified. For example, effects of late grounding of the ice and anomalies potentially related to methane emissions could not be separated efficiently. Visualizations of Δσ0 images likely reflect the temporal expansions of anomalies and are expected to be particularly useful for identifying target areas for future field-based research. Characteristic anomalies that clearly resemble the ones observed for Lake Neyto could be identified solely visually in the Yamal and Tazovskiy study regions. All data and algorithms produced in the framework of this study are openly provided to the scientific community for future studies and might potentially aid our understanding of geological lake seepage upon the progression of related field-based studies and corresponding evaluations of formation hypotheses.