Soil cryogenesis as a natural risk factor for gas pipelines in the permafrost zone during modern warming

The paper summarizes the experience of studying the effect of modern warming on the thawing depth of sandy and loamy soils in the permafrost zone. The definition of soil cryogenesis as a natural process and facies as the end result of soil cryogenesis as a process is given. The effect of soil cryogenesis facies on stress corrosion cracking of gas pipes of the Gazprom system in cold and warm seasons has been studied. It was found that the facies of soil cryogenesis are interconnected by the process of energy and mass exchange. It is shown that in the annual cycle, each facies formed by soil cryogenesis is the basis for the development of stress corrosion cracking of gas pipelines.

Analysis of the causes of engineering structures deformations at gas industry facilities in the permafrost zone

Construction of oil and gas infrastructure facilities on permafrost soils is the most important task of increasing the raw material base of the entire fuel and energy industry in Russia. Permafrost soil is a complex, multicomponent system, state of which depends on many factors. Buildings and structures built under such conditions, on the one hand, have a complex thermal effect on permafrost soils, and on the other hand, they perceive the consequences of changes in the characteristics of such soils. This situation leads to the fact that buildings and structures on permafrost soil during their life cycle are subject to complex and poorly predictable deformations. Article presents the results of a study for various degradation processes of permafrost soils that can be implemented at construction sites of industrial facilities. Analysis of the deformations causes for engineering structures at the gas industry in the permafrost zone is carried out. Series of reasons causing such deformations have been investigated. Comprehensive criterion for assessing changes in permafrost-geological conditions of industrial sites is proposed. It is suggested to apply the method of calculating the individual characteristics for the temperature regime of the territory to monitor and assess the conditions of heat exchange and predict changes in the geocryological conditions of permafrost soil.

CONSIDERATION OF GEOCRYOLOGICAL CONDITIONS IN THE DEVELOPMENT OF THE SUZUNSKOYE FIELD

Вследствие малоизученности геокриологических условий ряда скважин месторождений Сибири, авторы провели исследования, направленные на разработку методов стабилизации теплообменных процессов и сохранения природной среды. Была предложена эффективная методика сохранения баланса в системе скважина - пласт, что будет крайне актуально на месторождениях сибири, арктического и субарктического климатического пояса. Изучаемое нами Сузунское месторождение характерно тем, что оно состоит в области многолетнемерзлых пород (ММП) и подвержено их непрерывному воздействию. Оно принадлежит Западно-Енисейской зоне, которая, в свою очередь, входит в Западно-Сибирско-Хатангскую глубинку, характеризуемую высокой отрицательной температурой (Гинсбург, 1971). Общегодовая температура мерзлотного рельефа и пород меняется в огромной доле местности от-1°С вплоть до -5°С. Преимущественно холодные температуры характерны промерзшим осадочным породам равнин и террас, в плоскости которых сформирован низкий мохово-лишайниковый слой, который почти никак не противодействует выдуванию осадков.Помимо этого, в данной статье была проведена работа по моделированию теплообменных процессов между скважинами и зоной расположения многолетнемерзлых пород. The poor knowledge of the geocryological conditions of a number of wells in Siberian fields, the authors carried out research aimed at developing methods for stabilizing heat transfer processes and preserving the environment. An effective method for maintaining a balance in the well-reservoir system was proposed, which will be extremely important in the fields of Siberia, the arctic and subarctic climatic zones.The zone of the Suzunskoye field is located in the area of continuous influence of permafrost rocks (permafrost), also in geocryological connection it belongs to the West Yenisei subzone of the West Siberian-Khatanga permafrost hinterland (Ginsburg, 1971).The total annual temperature of the permafrost relief and rocks varies in a huge part of the area from -1° С to -5 ° С. Predominantly cold temperatures are characteristic of frozen sedimentary rocks of plains and terraces, in the plane of which a low moss-lichen layer is formed, which almost does not in any way oppose the blowing of sediments.In addition, in this article, work was, carried out to simulate heat transfer processes between wells and the permafrost zone.

Long-term climate-influenced land cover change in discontinuous permafrost peatland complexes

The discontinuous permafrost zone is undergoing rapid transformation as a result of unprecedented permafrost thaw brought on by circumpolar climate warming. Rapid warming over recent decades has significantly decreased the area underlain by permafrost in peatland complexes. It has catalysed extensive landscape transitions in the Taiga Plains of northwestern Canada, transforming forest-dominated landscapes to those that are wetland dominated. However, the advanced stages of this landscape transition, and the hydrological and thermal mechanisms and feedbacks governing these environments, are unclear. This study explores the current trajectory of land cover change across a 300 000 km2 region of northwestern Canada's discontinuous permafrost zone by presenting a north–south space-for-time substitution that capitalizes on the region's 600 km latitudinal span. We combine extensive geomatics data across the Taiga Plains with ground-based hydrometeorological measurements collected in the Scotty Creek basin, Northwest Territories, Canada, which is located in the medial latitudes of the Taiga Plains and is undergoing rapid landscape change. These data are used to inform a new conceptual framework of landscape evolution that accounts for the observed patterns of permafrost thaw-induced land cover change and provides a basis for predicting future changes. Permafrost thaw-induced changes in hydrology promote partial drainage and drying of collapse scar wetlands, leading to areas of afforestation forming treed wetlands without underlying permafrost. Across the north–south latitudinal gradient spanning the Taiga Plains, relatively undisturbed forested plateau–wetland complexes dominate the region's higher latitudes, forest–wetland patchwork are most prevalent at the medial latitudes, and forested peatlands are increasingly present across lower latitudes. This trend reflects the progression of wetland transition occurring locally in the plateau–wetland complexes of the Scotty Creek basin and informs our understanding of the anticipated trajectory of change in the discontinuous permafrost zone.