Northwest Siberia Research Articles

Ways of identifying lichen and plant species by the Nenets reindeer herders in Yamal

Yamal Nenets herders have historically developed a rich knowledge of lichens and vascular plants, which feature in the diet of their migratory reindeer herds in the tundra zone of northwest Siberia. In the Nenets language there are native names for certain species of lichens and other reindeer forage plants, including graminoids, herbs, shrubs, berries, and mushrooms. During participant fieldwork together with nomadic tundra Nenets herders, we documented names and definitions of reindeer food on herding territories during their long migration routes from the northern forest-tundra transition zone to the northern coastal tundra. Like many other Indigenous peoples of Siberia, Nenets have noticed that the Arctic is changing and some of its recent dynamics are seriously affecting their livelihood. The degradation of some lichen composition and cover on tundra pastures has also contributed to a decrease of herders’ linguistic palette for describing these losses in a concrete manner. Since the Nenets language is on the list of endangered languages of the world, this has an especially negative impact on the language skills and traditional knowledge of the younger generations of Nenets people, who may not know what these lichens look like and why they are important for the Nenets reindeer herding culture.

Socio-Ecological Consequences of Irrational Nature Use in the North of Western Siberia in the 1990s

The article is devoted to the analysis of environmental problems that arose as a result of the industrial development of the North of Western Siberia in the 1990s. The consequences of active, irrational use of natural resources in North-West Siberia for water, land resources and the atmosphere are considered. Based on the analysis of previously unpublished archival materials of the environmental prosecutor’s office of the Khanty-Mansiysk Autonomous Okrug, the author has established that the period of the 1990s had many environmental problems, including those related to the oil and gas production complex and human negligence. It is concluded that the main pollutant in the studied region was oil and oil products. Among the environmental problems, a special place is occupied by the pollution of soils and water resources, the violation of the balance of the ecosystem. Against this background, social problems arise: problems with the health of the population, a decrease in the quality of life, a decrease in opportunities for recreation, nature tourism and recreation; the emergence of additional factors of social inequality and social tension. At the same time, the author does not deny the economic importance of oil production and proposes to more actively introduce mechanisms for sustainable environmental management. The author’s research contributes to the development of ecological history in the North of Western Siberia.

Classification of cryogenic-landslide landforms for mapping and prediction

A classification of cryogenic-landslide landforms is developed for mapping their distribution and dynamics. It is based on the previously suggested classification subdividing cryogenic landsliding into two main types: cryogenic translational landslides (or active-layer detachment slides), and cryogenic earth flows (or retrogressive thaw slumps). The increased proportion of retrogressive thaw slumps compared to active layer detachments in the North of West Siberia in the last decade creates the need for an expanded classification of cryogenic earth flows. One of the important issues is separating the process of landsliding and resulting landforms, which in English are covered by one term ‘retrogressive thaw slump’. In dealing with the landforms, we distinguish (1) open and (2) closed ones. Open cryogenic-landslide landforms are those formed by the retreating of the coast bluff due to the thaw of ice or ice-rich deposits with an additional impact from wave or stream action. Closed cryogenic-landslide landforms are those initiated on a slope landward, and thawed material is delivered to the coast or stream through an erosional channel. Morphologically we distinguish thermocirques and thermoterraces depending on the shape of the retreating headwall, crescent or linear, respectively. An important issue is the type of ground ice subjected to thaw: tabular, ice-wedge or constitutional ground ice are distinguished. Landforms can be active, stabilized or ancient. One can find both single landforms and their combination. The classification is based on a significant amount of field studies and interpretation of remote sensing data. Mapping of the cryogenic-landslide landforms is suggested using the proposed classification and indication features. The classification is based on the experience obtained mainly in the north of West Siberia. Applying it to other regions may require additional studies.

Productivity of unconventional Senon reservoirs in the north of West Siberia

At the current stage of geological exploration, hydrocarbon deposits have been discovered in complex reservoirs that are "unconventional" in nature. In particular, at the Medvezhye field, according to the interpretation of seismic surveys and the drilling of exploratory wells, a gas deposit was discovered in the Senonian deposits of the Nizhneberezovskaya suite of Upper Cretaceous deposits. The gas deposit of the NB formation of the Medvezhye field is characterised by productive reservoirs, mostly represented by mudstones and opoka-like clays. These rocks are characterized by low filtration parameters. Commercial gas inflows from secondary reservoir openings indicate the presence of fractured rock, as confirmed by core testing, mechanical logging. A comprehensive analysis of hydrodynamic studies of field parameters, such as reservoir pressure, drawdown, flow rate, allows calculating the filtration characteristics of a productive formation. The performance of fractured and mixed pore-fractured reservoirs is determined using induction diagrams and pressure recovery curves, the reservoir hydrodynamic model and methods for improving development in complex "unconventional" reservoirs are refined.

Distribution and Morphometry of Thermocirques in the North of West Siberia, Russia

The Arctic zone of West Siberia (Yamal and Gydan peninsulas) is an area with continuous permafrost and tabular ground ice close to the surface, active thermodenudation, and related landforms: retrogressive thaw slumps (RTS); in Russian referred to as thermocirques (TC). The dimensions of most TCs have not been determined so far. We use Sentinel 2 imagery to measure each TC area ranging from 0.55 to 38 ha with a median of 2.5 ha. Around 95% of TCs have an area of less than 10 ha. The largest areas are gained due to the merging of several neighboring TCs. The ArcticDEM is used to determine TC edge elevation and slope angle. In general, the Median TC of the Yamal peninsula has an area of 1.8 ha, an elevation of the edge of 17.7 m, and a slope angle of 2.5°. The Median TC of the Gydan peninsula has an area of 2.6 ha, elevation of the edge of 29.4 m, and slope angle of 3°. TCs of the Gydan peninsula occupy higher positions and slightly steeper slopes compared to TCs of the Yamal peninsula. The ranges of the median and the largest TC areas are consistent with the reported RTS dimensions in North America.

A Model of a Shear Landslide Wedge with Subsequent Hydraulic Rupture as an Explanation for an Anomalous Section of the Bazhenov Formation in the North of West Siberia. Article 1. Section Description, Lithology, and Palynology

A Model of a Shear Landslide Wedge with Subsequent Hydraulic Rupture as an Explanation for an Anomalous Section of the Bazhenov Formation in the North of West Siberia. Article 1. Section Description, Lithology, and Palynology

Multiphase cryogenesis and incipient paleosol development during MIS 2 in North-Western Siberia: Detailed chronostratigraphy, paleoenvironmental significance, and comparison with the global and European records

New widely accepted scenario of glacier-free landscape evolution in the north of West Siberia during MIS 2 (Sartanian cryochron) raises a challenge to find new regional stratigraphic markers in the absence of reliable continuous sedimentary units. The cryogenic and pedogenic structures have been long applied for the European Late Pleistocene stratigraphy in the extra-glacial regions. We argue that such structures might also provide important markers for the detailed stratigraphic scheme in the north of West Siberia. Two types of indicators were suggested. Firstly, morphological features and ranges of radiocarbon dates in epigenetic ice wedge pseudomorphs of higher terraces are sensitive to events of abrupt climate amelioration. Regional analysis of radiocarbon dates of ice wedge pseudomorphs indicated four warmer climatic events in the Late Pleistocene – the Early Holocene (ca. 18000–16500 cal BP, ca. 13800–12500 cal BP, ca. 11700–11100 cal BP, and ca. 10400–9000 cal BP). They correlate to climatic events of the Greenland ice core record with minor temporal lag. Secondly, more detailed cryogenic-paleosol-sedimentary sequences formed at lower terraces where sedimentation continued during MIS 2 are another type of suggested indicator. Their morphological and paleobotanical analyses and radiocarbon dating provided a reconstruction of local paleolandscape evolution with events of cryohydromorphic soil development (ca. 15700–15300 cal BP, ca. 11200–9000 cal BP). Similar late-glacial paleosols are encountered in the European loess sequences. We propose that the cryopedogenic horizons, including ice wedge pseudomorphs, cryoturbation structures, and cryohydromorphic paleosols, are reliable regional stratigraphic markers in the north of West Siberia for the Sartanian cryochron.

Localized Vegetation, Soil Moisture, and Ice Content Offset Permafrost Degradation under Climate Warming

Rapid Arctic warming is expected to result in widespread permafrost degradation. However, observations show that site-specific conditions (vegetation and soils) may offset the reaction of permafrost to climate change. This paper summarizes 43 years of interannual seasonal thaw observations from tundra landscapes surrounding the Marre-Sale on the west coast of the Yamal Peninsula, northwest Siberia. This robust dataset includes landscape-specific climate, active layer thickness, soil moisture, and vegetation observations at multiple scales. Long-term trends from these hierarchically scaled observations indicate that drained landscapes exhibit the most pronounced responses to changing climatic conditions, while moist and wet tundra landscapes exhibit decreasing active layer thickness, and river floodplain landscapes do not show changes in the active layer. The slow increase in seasonal thaw depth despite significant warming observed over the last four decades on the Yamal Peninsula can be explained by thickening moss covers and ground surface subsidence as the transient layer (ice-rich upper permafrost soil horizon) thaws and compacts. The uneven proliferation of specific vegetation communities, primarily mosses, is significantly contributing to spatial variability observed in active layer dynamics. Based on these findings, we recommend that regional permafrost assessments employ a mean landscape-scale active layer thickness that weights the proportions of different landscape types.

Cryohydromorphic paleosols in the north of West Siberia as indicators of the warm stages of the Late Pleistocene and their link to the cryogenesis development

The aim of the study. The aim of the study was to find and justify specifics of the paleosol development in the north of West Siberia, revealing soils levels, associated with climate warming during sea isotope stages (SIS), namely MIS-5, MIS-3 and at the end of MIS-2. Location and time of the study. The research was conducted during the last 10 years in the representative area between the Polar Circle and the sub-latitudinal sector of the Ob river all over the area. We carried out paleopedological and paleocryological investigations with fieldwork in the basin of the Vakh River (right tributary of Ob), the Taz and Nadym Rivers, where the soil pits were studied, and paleosols were discovered for the first time. Methods. The methodology has been focused on detailed study of the paleosols discovered by the present authors based on the investigation in respect to the interaction of paleopedogenetic and cryogenetic processes. Also, the encountered paleosols have been, as well compared to the surface Holocene soils that comprises an important element of analysis of the paleopedological records. For age determination we applied radiocarbon dating of organic residues and humus, contained in the paleosols, as well as U/Th-dating in paleosols. Results. Several paleosol levels were identified in the study area. The paleosol of the early substage of MIS-5 (MIS-5e) had signs of forest pedogenesis without permafrost, whereas the soils of late substages of MIS-5 and MIS3 showed evidence of gleying and cryogenesis; the paleosol corresponding to the end of MIS-2 was best represented by gleyic pedosediments in the ice-wedge pseudomorphs. The studied paleosols indicate the permafrost state of the soil-forming sediments in all phases of the Late Pleistocene with the exception of MIS-5e; the finding is important for the paleoenvironmental reconstruction. The article presents the data about wide distribution in the study region of the polygonal structures represented by the ice-wedge pseudomorphs formed in the coldest phases MIS-4 and MIS-2. The pseudomorphs were developed syn-cryogenically when permafrost still existed and were closely related to the formation of cryohydromorphic paleosols. Within the entire sequence of MIS-3 deposits initially ground wedges are common, also indicating syn-cryogenic development, however, under less strong freezing conditions than during MIS-2. Yet at the end of MIS-3 in the upper part of the sequence cryohydromorphic soils appeared again, as a sign of approaching to the MIS-2 cryochron. It was shown that the fills of the ice wedge pseudomorphs contain well preserved redeposited materials of the cryohydromorphic paleosols, including fragments of the humus horizons. It was suggested that the material from such redeposited pedosediments could be used for the radiocarbon dating and for sampling for the paleobotanical investigations. Conclusions. The obtained results cast doubt on the hypothesis of domination of the cold deserts and ice sheets in the study region during the Pleistocene and hence the formation of only extremal soils. There is evidence indicating the existence of well-developed vegetation and soil cover during the cryochrons with sufficient and in some areas excessive soil moisture, due to shallow permafrost table. The interaction of the paleopedogenetic and paleocryogenic processes resulted in rather informative relict objects, and their studies provide highly reliable results about the factors of past pedogenesis.

СОСЬВИНСКАЯ ЦЕРКОВНО-ПРИХОДСКАЯ ШКОЛА В ИСТОРИИ ПРОСВЕЩЕНИЯ НА ОБСКОМ СЕВЕРЕ В КОНЦЕ ХIХ – НАЧАЛЕ ХХ ВВ.

The relevance of the article is due to the insufficient study of the system of education in the North of West Siberia before the revolution. Scientific information sources on the history of school education in the Khanty-Mansiysk Autonomous Okrug are in a formative stage. Sosvinskoye parish accounting documents provided the basis for the research. The documents contain the information, which has allowed the author to restore the history of one of typical parish schools of the region and to narrate its first teachers and benefactors. The education development issues are considered in the frame of the history of Beryozovsky uyezd orthodox parish. Schools construction was dictated by the Executive Order of 1884 on organization of parish schools nationwide. A conclusion has been made that the Russian population of the region (priests, merchants and urban commoners) needed school education. It is highlighted in the article that the Beshkiltsev family played an important part in the material support of Sosvinskoye parish school.

Floodplain soils on the soil map of the Russian Federation, scale 1 : 2.5 M, 1988, in the Russian soil classification, 2004

The largest area of taiga gley-differentiated soils on the Soil map of Russian Federation, scale 1:2.5 M, is located in the north of West Siberia. Small areas are dispersed over the northwestern European Russia, Eastern Siberia and the North-East. Interpretation of taiga gley-differentiated soils in terms of Russian soil classification system (2004) is rather ambiguous owing to high diversity of ecological conditions where these soils occur, аs well as variability of soil morphological, chemical, and physicochemical properties in diverse mapping units. Comparing properties of taiga gley-differentiated soils described in the Program of the map (1972) and in regional publications with the diagnostic criteria for soil types in some orders of the Russian classification system made it possible to find adequate names and taxonomic position for these soils. Thus, taiga gley-differentiated soils in the middle and northern taiga of Western Siberia proved to be allocated to several orders: weakly differentiated and gleyed soils with a brown profile were referred to the order of organo-accumulative soils as shallow-peat gleyic soils; their more hydromorphic variants – taiga gley-differentiated shallow-peat soils were defined in the order of gleyzems, as peat gleyzems, soil with morphologically differentiated profile having a particular cryogenic structure were qualified for svetlozems and iron-illuvial gleyic svetlozems in the order of cryometamorpic soils, and for eluvial-metamorphic soils of the same order in case of cryogenic structure was absent. Taiga gley-differentiated soils in their northwestern area are confined to varved clays and correspond to (soddy-)eluvial-metamorphic gleyic soils.

Sartanian (MIS 2) ice wedge pseudomorphs with hydromorphic pedosediments in the north of West Siberia as an indicator for paleoenvironmental reconstruction and stratigraphic correlation

Within the glacier-free scenario of the MIS 2 (Sartanian cryochron) environment in the north of West Siberia, it is important to search for the new regional paleoecological records and stratigraphic markers for this period. We studied large ice-wedge pseudomorphs filled with gleyic pedosediments developed on the high river terraces in the Nadym and Taz rivers basins as a tracer of the surface cryogenic and pedogenic processes during MIS 2. Field morphological observations and measurements, palynological analysis and radiocarbon dating of organic matter from soils and pedosediments were performed. Two sets of paleoecological indicators were discriminated: pseudomorph geometry evidence of the processes and conditions of ice wedge formation during the Last Glacial Maximum whereas the paleopedological and paleobotanic results from the fills recorded the environments of ice wedge melting at the end of MIS 2. Paleotemperatures 7–10 °C lower than at present are inferred during the major part of Sartanian, even at its end continuous permafrost persisted providing development of swampy tundra vegetation and cryohydromorphic palaeosols. We propose to define Taz-Nadym cryopedogenic horizon as a representative regional unit for MIS 2 and to correlate it with synchronous cryogenic and palaeosol units in Central and Eastern Europe.

Preserved lipid signatures in palaeosols help to distinguish the impacts of palaeoclimate and indigenous peoples on palaeovegetation in northwest Siberia

Arctic reindeer herders demonstrate resilience to climate fluctuations by adjusting their pastoral practices to changing environments. The multiple phases of occupation at one of the oldest identified reindeer-herding sites, IA^rte 6 on the IA^mal peninsula, northwest Siberia, are thought to be linked to its local vegetation cover. Here we provide information on local palaeovegetation and climate shifts which occurred between the 7th and the 11th century CE based on lipid biomarkers. Aliphatic compounds, pentacyclic triterpenoids, branched glycerol dialkyl glycerol tetraethers (brGDGTs) and other lipids were analysed in four separate palaeosols from two loess-palaeosol sequences at the site. Based on different indices, the impact of human- or root-derived lipids and post-depositional microbial degradation on the signature of the studied pedosequences seem limited, which indicates that palaeobiomarkers are well preserved and representative of the analysed compounds.n-Alkanes, n-carboxylic acids, n-aldehydes and pentacyclic triterpenoids point to the progressive colonization of grasses, sedges and herbs at the site, which can be attributed to the regional decrease in temperature suggested by bacterial-derived brGDGTs. During the last phase of occupation, however, when proxies point to increasing temperatures, and shrubs would normally be expected to return, the shrub cover continued to decrease, probably due to the impact of camping and holding reindeer at the site. The decoupling trends observed for particular pentacyclic triterpenoids as potential dwarf birch biomarkers could suggest a preferential shift of species within shrubs, probably influenced by human activities. Multi-family lipid biomarker analysis therefore made it possible to distinguish anthropogenic impacts on the local vegetation cover from regional climatic changes, and show how significant the impacts of humans on local vegetation can be, even in extreme environments where such activities are limited.

Isotopic composition of heterogeneous ice wedges in peatlands of the Pur‐Taz interfluve (northern West Siberia)

AbstractHeterogeneous ice wedges were studied within the peatland of the drained lake on the Pur‐Taz interfluve (67°20′14.8″, 078°55′47.1″, Northwest Siberia). The elements of the ice‐wedge structure were identified: young ice wedge, shoulders, selvages, closed‐cavity ices, and ice lenses in a peatland. Different genetic types of ice (ice vein, congelation ice, and segregated ice) were revealed by analyzing the elements of the ice‐wedge structure under polarized light and analyzing their chemical compositions. Genetic types of the ice indicate the different mechanisms of ice‐wedge formation. The ice vein forms due to fast bilateral freezing of primarily meltwater in a thermal contraction crack. The congelation ice forms due to the slow freezing of free water that has accumulated into a thermokarst cavity. The segregated ice forms due to pore water migration to the freezing zone. The elements of the ice‐wedge structure have variable stable isotope values (δ18O from −13.5‰ to −21.9‰ and δD from −87.7‰ to −154.6‰). The high range of deuterium excess values (13.8‰ to 32‰) indicates fractionation at condensation. The mean winter paleotemperature calculated using Vasil’chuk’s equations for the ice‐wedge pats formed by the ice veins varied in the range of −18 to −22°C, which is not very different from current values and is consistent with the isotopic data of ice wedges from nearby regions of Northwest Siberia. The paleotemperature average error can equal 4.5°C if we ignore the data on the ice petrographic analysis. The error depends on where and how the ice wedges are sampled, because of varying genetic types within the ground ice. This could lead to different palaeoclimatological interpretations.

Declining Growth Response of Siberian Spruce to Climate Variability on the Taiga–Tundra Border in the Putorana Mountains (Northwest Siberia)

Global warming is most pronounced at high latitudes where temperatures increase twice as fast as the global average. Boreal forest growth is generally limited by low temperatures, so elevated temperature is supposed to enhance biomass production and carbon sequestration. A large amount of evidence has recently shown inconsistent responses of tree growth derived from annual tree rings to increasing temperature. We studied Siberian spruce growth in the remote and isolated Putorana Mts, Western Siberia in populations at its natural distribution limit. Tree ring cores were sampled along vertical transect in 100, 200 and 350 m a.s.l. as the aim was to identify the tree growth rate at different altitudes. Detailed sampling site descriptions served to identify possible factors controlling the growth rate in extremely heterogeneous environments. Monthly climate data for the period 1900–2020 were extracted from the gridded CRU database. Tree ring chronologies confirmed long-lasting limited growth, and despite high year-to-year ring width variability, synchronous growth at vertical study sites dominantly controlled by climate. The positive tree ring growth response to summer temperature was significant for most of the 20th century but dramatically changed in recent decades, when unusually warm summers were reported. There was no, or even a negative growth rate correlation with precipitation, which indicates a sufficient water supply at the study sites. Elevated temperature in this region with a continental climate might turn the study localities to water-limited areas with many negative consequences on tree growth and related ecosystem services.

Mercury in bottom sediments of Russian Arctic lakes

Abstract. This article presents the results of studying the distribution of mercury in the cores of bottom sediments of both background and technogenic Arctic lakes in three regions: the Kola North, Malozemelskaya tundra and northwest Siberia. For all cores, the elemental composition, granulometry, and loss on ignition (LOI) were determined layer by layer. Mercury showed a significant excess of the local background in the near-surface sedimentary layers of most lakes. Fluxes of mercury from the pre-industrial period to the present were calculated. We discuss the possibility of technogenic pollution due to transboundary transfer.

Female festive costume of the Khanty and Mansi in the late 20th — early 21st century: dynamics and functions

In order to determine dynamics and causes of transformation of everyday dress into a festive costume, specifics and functions of the women’s costume of the Khanty and Mansi have been studied. Towards this, the comparative-typological method was employed to study the costume composition, its local features, and differences with respect to the traditional everyday dresses, and the functions of the costume were determined. The study is based upon the materials of ethnographic expeditions carried out in the 1990s–2010s in the regions occupied by the Ob Ugric population (North-West Siberia and Northern Trans-Urals). It has been ascertained that the festive costume commonly comprised a dress, a breast decoration, and a shawl, and in its local variants it was complemeted by other items. The costume was all-season and had common and local elements. The common elements include multi-completeness (it consists of several items), variability according to weather conditions, use of silk and woolen fabrics and beads. The local specifics are manifetsed in the costume composition, silhouette variability, and techniques of decoration. In the end of the 20th — beginning of the 21st century, traditional clothing of the Khanty and Mansi changed in the appearance due to the use of modern synthetic materials (it changed the colour, sillhuette, means and techniques of decoration) and became merely festive. To the large extent those changes were caused by the industrial development on the territory occupied by the Ob Ugric population in the last quarter of the 20th century, and later by the cultural, social, and economic transformations in Russia. The range of use of the traditional clothing shrank due to the spread of factory-made clothing. The growing interest to the ethnic culture stimulated demand for the national costume. It has become made from import synthetic fabrics, because the home-produced cotton fabrics disappeared from the shops. New fabrics changed the appearance of the clothing and its function, as it became merely festive.

Life history of the ground beetle Diacheila polita (Faldermann, 1835) (Coleoptera: Carabidae) in Subarctic and Arctic of North Europe and West Siberia

Life history of the ground beetle Diacheila polita (Faldermann, 1835) (Coleoptera: Carabidae) in Subarctic and Arctic of North Europe and West Siberia

Social agency and prestige technology: serial production of gold appliqués in the early Iron Age north-west China and the Eurasian steppes

ABSTRACT Recent discoveries in north-west China and the Central Asian steppes have shed new light on the study of power display and material connections amongst nomadic groups during the development of gold-making technology in Iron Age Eurasia. Bringing together material science and archaeological approaches, this paper presents an interdisciplinary study of serially produced gold artefacts recovered from the elite burials of north-west China, to gain a better understanding of the inventive nature of early gold-making industry. In particular, we find that the technology used to craft the gold appliqués found in the Xigou cemetery (3rd-2nd centuries BCE) in north-west China attested to the use of moulds or matrices for serial production, closely linked to technological practice of the central Asians steppes. We consider the spread of the peculiar technique and iconography as a tangible way to examine technology transfer and cultural interactions. The contextual analysis reveals that the mould-pressing technique, the animal-style gold artefacts, and the burial practice of using prestigious gold as body adornment constitute a shared set of material expressions of the status and power of nomadic elites in north-west China, Kazakhstan and southern Siberia. Technological practice, in turn, opens up new research avenues in the field, recalibrating our recognition and understanding the active involvement of material objects in human life and culture.

Using Response Surface Analysis to Estimate Time of The Gas-Water Contact Lift in Yamburg Gas Field Conditions

Like many of the fields in northwest Siberia, the Yamburg oil and gas condensate field is in the final production stages. This, therefore, results in an accumulation of a large amount of formation water in the inflow at the bottom of the well. Response surface analysis is used as a new technique to gain a detailed understanding of the relationships between combinations of two predictor variables and an outcome variable. This approach was applied to the Yamburg field to estimate the time of the gas-water contact, considered as the result variable, by taking into account two groups of predictive variables which correspond to the reservoirs grouped by their lithological characteristics. The results of the predicted gas-water contact time were compared to the expected gas-water contact time, the data of which were taken into account for the study. Using the model parameters as well as the three-dimensional response surface, which was constructed to facilitate and improve the interpretation of the results, it was then possible to predict the gas-water contact time under certain conditions.