Gas Prospects Research Articles

Identifying Active Rather than Total Methanotrophs Inhabiting Surface Soil Is Essential for the Microbial Prospection of Gas Reservoirs.

Methane-oxidizing bacteria (MOB) have long been recognized as an important bioindicator for oil and gas exploration. However, due to their physiological and ecological diversity, the distribution of MOB in different habitats varies widely, making it challenging to authentically reflect the abundance of active MOB in the soil above oil and gas reservoirs using conventional methods. Here, we selected the Puguang gas field of the Sichuan Basin in Southwest China as a model system to study the ecological characteristics of methanotrophs using culture-independent molecular techniques. Initially, by comparing the abundance of the pmoA genes determined by quantitative PCR (qPCR), no significant difference was found between gas well and non-gas well soils, indicating that the abundance of total MOB may not necessarily reflect the distribution of the underlying gas reservoirs. 13C-DNA stable isotope probing (DNA-SIP) in combination with high-throughput sequencing (HTS) furthermore revealed that type II methanotrophic Methylocystis was the absolutely predominant active MOB in the non-gas-field soils, whereas the niche vacated by Methylocystis was gradually filled with type I RPC-2 (rice paddy cluster-2) and Methylosarcina in the surface soils of gas reservoirs after geoscale acclimation to trace- and continuous-methane supply. The sum of the relative abundance of RPC-2 and Methylosarcina was then used as specific biotic index (BI) in the Puguang gas field. A microbial anomaly distribution map based on the BI values showed that the anomalous zones were highly consistent with geological and geophysical data, and known drilling results. Therefore, the active but not total methanotrophs successfully reflected the microseepage intensity of the underlying active hydrocarbon system, and can be used as an essential quantitative index to determine the existence and distribution of reservoirs. Our results suggest that molecular microbial techniques are powerful tools for oil and gas prospecting.

Study of Oil and Gas Prospecting Techniques: A Review

Consumption of petroleum products continues to grow steadily. In 2020, oil consumption numbers surpassed exploration's, indicating a possible market imbalance. That said, the demand for new oil reserves becomes essential. Prospecting techniques for these commodities are used to have greater accuracy before drilling a well. Different Geological, Geophysical, and Geochemical methods are applied with different principles in their search, with Seismic being the most widely used technique. Sniffers have gained ground among geochemical methods, and new technologies are emerging. Despite many methods, none is conclusive and should be used in conjunction with others, whether in the prospecting area or for leak monitoring.

Shale gas play of the silurian hot shale, Ghadames Basin, North Africa: Insights from integrated geochemistry and basin modeling

The lower Silurian hot shale in the Ghadames Basin was investigated to provide a regional assessment of the future prospects of shale gas play as an important unconventional resource system in one of the top African superglobal petroliferous sedimentary basins. The unconventional natural gas potential of the hot shale was studied based on regional improved organofacies assessment, thermal maturity, the timing of generation and expulsion, and sweet gas spot analysis, such as gas in place (GIP), total expelled gas (TEG), and total retained gas (TRG). The integration between regional geology and organic geochemistry, together with the proper regional utilization of the multi-dimensional basin modeling to better appreciate the importance of the Silurian hot shale as a key future shale gas unconventional-rich petroleum system (URPS) in the Ghadames Basin. The relationship between the richness and thermal parameters, such as the total organic carbon indicator (%TOC), hydrogen index (HI), measured and time step (calibrated models) vitrinite and equivalent vitrinite (%VRo) reflectance were used to develop quality control models for the regional natural gas spots of the Silurian hot shale were present-day mapping presentations are utilized as well for each parameter to better appreciate the lateral variability of the dry gas volumes. Regional basin control parameters from several key wells, such as heat flow levels, formation pressure system, and basin porosity were successfully utilized for the hot shale gas play resource screening (sweet spots) study utilizing multi-dimensional modeling approaches. The established regional spatial type B marine organofacies of the hot shale with excellent geochemical properties (∼18 %TOC) and regionally sufficient thermal maturation (∼2.45 %VRo, post-mature stage) indicate a significant amount of natural gas expelled and retained that has occurred in the Silurian hot shale system. The estimated GIP of the hot shale is about 120 bcf/km2 (equivalent to 320 bcf/section). The maximum expelled gas (TEG) amount is defined with values up to 88 bcf/section and the total estimated volume of the retained gas (TRG) is up to 96 bcf/km2, with the current geological architecture, geochemical properties, volumes, and distribution of the hot shale dry gas sweet spot in the Ghadames Basin. The hot shale can be considered in the near future for extensive further studies and exploration and development plans in Libya, Algeria, or Tunisia.

DDViT: Advancing lithology identification on FMI image logs through a dual modal transformer model with less information drop

Lithology is an essential topic in oil and gas reservoir studies. Lithological observation lays the foundation for assessing oil and gas prospects and guides future exploration and development. Currently, the prevailing approach in lithological observation heavily depends on the manual analysis of core samples. However, such an approach is highly subjective and time-consuming. With the development of deep learning, some automated deep learning-based methods have been proposed for lithology interpretation from logging curves. However, the Fullbore Formation MicroImager (FMI) image logging, while widely used in the oil field exploration and development process, is occasionally deployed and utilized for lithology identification. In this work, we proposed a Dual-modal Drop-less-information Vision Transformer (DDViT), an FMI image lithology identification model based on transformer architecture. DDViT uses a dual-modal architecture to identify lithology using two different image modalities, namely dynamic FMI images (FMI_DYN) and static FMI images (FMI_STAT). These modalities reflect the local and overall characteristics, respectively. Furthermore, DDViT uses a less-information dropping module to drop the blank band information inherent in the FMI images to make our model more rational and stable. DDViT achieved a 90.81% lithology identification accuracy on Fengxi Well A of the western Qaidam Basin, providing a new approach to lithology identification and demonstrating the great potential of deep learning in geological images.

ВПЛИВ МІГРАЦІЇ ФЛЮЇДІВ НА МАГНІТНУ МІНЕРАЛОГІЮ ҐРУНТІВ

Background. The war in Ukraine arises the urgent need to intensify hydrocarbon production on its own territory in order to maintain and develop the country's energy independence. The effectiveness, low cost and relevance of the involvement are demonstrated by magnetic methods of studies of the near surface geological section and the soil for the oil and gas prospecting. Methods. The methodology of magnetic studies for the hydrocarbon prospecting is based on the methods of studying the environmental magnetism and soil, precision magnetic survey of natural systems and authigenic models of changes in magnetic mineralogy under the influence of hydrocarbon fluid migration. Results. The crucial aim is to distinguish the sources of the formation of the magnetic minerals. In most cases, soils contain minerals of natural pedogenic origin, authigenic secondary magnetic minerals, and sometimes detrital fine-coarse magnetic phases. For Ukraine, magnetite, maghemite, hematite, and goethite are the most common magnetic minerals of soils of the pedogenic origin. At the same time, the experience of conducting magnetic mineralogical analyzes of soils in the territories of oil and gas deposits indicates the presence of iron sulfides. First of all, monoclinic pyrrhotite is identified. The soils also contain accompanying hexagonal pyrrhotite, pyrite, and greigite. The results of thermomagnetic analyzes and hysteresis loops of soil samples collected at the territories of hydrocarbon deposits are presented and their mineral composition is analyzed. Conclusions. The results of the study of the impact of hydrocarbon fluid migration (microseepage) on the change in the mineral composition of soils indicate significant informativeness and the perspective of introducing the method into the complex of geological exploration works at various stages. Authigenic changes of magnetic minerals in the near surface geological section and soil, as well as natural and anthropogenic accumulation of hydrocarbon products in soils, cause changes in magnetic properties and form magnetic field anomalies.

Prospects for Russian Gas in China

Prospects for Russian Gas in China

PALEOFACIES — BASIS OF RESERVOIR DEVELOPMENT DESIGN

Apt-Alb-Cenomanian age rocks (K1a-al + K2s) within the northern part of the West Siberian oil and gas province (OGP) are the main commercial gas production target in the Russian Federation. However, at present there are certain prerequisites and significant reserves to increase the raw hydrocarbon base and gas production in the central regions of Western Siberia. For further study of the geological structure of these sediments in order to assess their oil and gas potential, it is necessary to set up and carry out complex geological, geophysical and special studies (including sedimentological identification of sediments, detailed reconstruction of paleogeographic sedimentation settings, paleofacial analysis of rocks, petrophysical support of the works). This will make it possible to increase the accuracy and reliability of the planned works on oil and gas prospecting and exploration, as well as to carry out a qualitative forecast of the area development of promising complex reservoir rocks, to perform a full calculation of the initial geological reserves of hydrocarbons for a number of new objects (including PK5, PK7, PK8) and to build highquality geological and hydrodynamic models of hydrocarbon deposits necessary for the design of their further development.A detailed analysis of the primary geological and geophysical materials at our disposal has shown that during the formation of the Pokur Formation in the Middle Ob oil and gas bearing area (OGO) there were heterogeneous conditions of sedimentation — from purely continental to coastal-marine. High lithologic and facies heterogeneity of the studied sediments is observed everywhere. These circumstances complicate the processes of detailed correlation in these sediments, and in some cases — unrealized in practice even within one exploration area. Stratification of productive strata is the most important part of oil and gas prospecting and exploration. According to the results of our studies, the upper strata are most well traced (in some cases up to the hypsometric level of PK3-4 strata occurrence). Their confident area correlation makes it possible to identify smaller stratigraphic subdivisions (packs) in these strata and to determine the paleofacial genesis of these sediments.

Использование вероятностных методов обработки геолого-геофизических данных на территории Восточно-Сибирской платформы для прогноза нефтегазовых перспектив концентрических структур

The study aims in showing the results of forecasting oil and gas prospects of some concentric structures in the East Siberian Platform area. The research was conducted using probabilistic data processing methods based on the use of preliminary analysis of various geological and geophysical data (histograms of the thickness of the Earth's crust, lithosphere, sedimentary layer, geothermal gradient, density of tectonic faults), evaluated for the main oil and gas basins in the Russian Federation. The results obtained were used to forecast oil and gas prospects of concentric structures in the East Siberian Platform area. In particular, probabilistic processing methods using five geological and geophysical types of data in the region were used to calculate probability values for fifteen different concentric structures. The results of using probabilistic methods for processing various types of geological and geophysical data, measured within several concentric structures on the territory of the East Siberian Platform are considered. According to the calculated probability values, the areas of three concentric structures (Nepsko-Botuobinskaya, Angarskaya, Sayano-Yeniseyskaya), located in the south of the East Siberian Platform promising for the search for new areas with hydrocarbon deposits, were predicted. Six other concentric structures (Kureyskaya, Tungusskaya, Bakhtinskaya, Kamovskaya, Yenisey-Khatangsk, Zabaikalskaya) require more comprehensive geological prospecting, as their individual sectors may be promising for oil and gas exploration.

Formation conditions of hydrocarbon systems in the Turkmen sector of the South Caspian basin

Background. The formation and placement conditions of hydrocarbon systems and their accumulation in the Turkmen sector of the South Caspian basin are considered.Aim. To model the existing hydrocarbon systems in the Turkmen sector of the Caspian Sea based on available data.Materials and methods. Statistical generalization and systematization of available data was carried out. Research materials included fund and reference sources, fieldwork data, and publications by Sh.F. Mehdiyev, I.S. Guliyev, M.Z. Rachinsky, S.S. Djibouti, S.A. Aliyev, V.Y. Kerimov, V.V. Kolodiya, etc.Data modeling was performed in the PetroMod software.Results. The conducted numerical modeling established the formation conditions of the key elements of hydrocarbon systems, including oil and gas mother strata, reservoirs, and seals. Hydrocarbon prospects were identified. The main spatial and temporal patterns in the development of generation, migration, and accumulation processes of hydrocarbon fluids were determined, along with the formation conditions of traps. A map depicting potentially promising areas, objects, and plays was drawn. Hydrocarbon prospects were identified. Directions for oil and gas prospecting and exploration in the Turkmen sector of the Caspian Sea were substantiated.

Forecast of oil and gas reservoirs of the Sea of Okhotsk based on interpretation processing of seismic material

Background. This article analyses the results of geological and geophysical studies conducted in the Okhotsk Sea area with the purpose of developing methods for processing seismic information in combination with other data to solve the problems of forecasting hydrocarbon deposits.Aim. Solving problems of forecasting hydrocarbon deposits through the development of a structural and technological scheme for prospecting and evaluation of a geological and geophysical model to identify images of oil and gas deposits.Materials and methods. The research methodology included selection of the location of points for simulating “vertical wells” in order to analyze the geodynamics of the medium; multiplex parametric transformations of wave fields taking into account diagnostic significant attributes and building a multiparametric cluster; selection of oil and gas deposits; formation of images of oil and gas deposits; local forecast of improved reservoir properties and saturation; refinement of the geometry of target surfaces with forecast data in actual points (vertical wells); forecast of the area of target surfaces; spatial mapping of the largest hydrocarbon deposits.Results. Forecasting of oil and gas prospects in the Okhotsk Sea in areas where there is no deep drilling can be carried out using the following technologies: detailing the structural and tectonic structure of hydrocarbon traps; multi-feature prediction of hydrocarbon deposits; decomposition of the dispersion of the wave field; low-frequency resonance of seismic emission geodynamic noise; selection of oil and gas-containing objects.

Source and significance of Cretaceous oil seepage in the northern Ordos Basin, China

It has long been believed that the region on the north of the Dongsheng gas field has only limited exploration potential due to the lack of effective source rocks. However, several areas of Cretaceous oil seepage have been discovered in the area and their sources are unclear. In this study, the organic geochemical characteristics of these oil seepages and potential source rocks (coals and carbonaceous mudstones of different formations) are examined using TOC analysis, pyrolysis, gas chromatography-mass spectrometry, and carbon isotopes. The results show that the oil seepages are low-to-moderately mature (0.63 %-0.78 % Rc) and slightly biodegraded. The molecular biomarker compositions of the oil seepages are characterized by C29≫C28>C27 normalized relative abundance of regular steranes, high values of Pr/Ph, (C19TT + C20TT)/C23TT and C24TeT/C26TT ratios, low values of Ga/C30H, and low abundance of dibenzothiophenes. The biomarker compositions, as well as the stable carbon isotopes, indicate that the source of the oil seepages was deposited in a lacustrine fluvial/deltaic environment under oxic to sub-oxic conditions, with organic matter input predominantly from terrigenous higher plants. Oil-source correlation revealed that the oil seepages were closely related to the coals in the Shanxi formation in the south source kitchen, implying that the hydrocarbons generated in the south source kitchen have been able to migrate to the north edge of the Ordos Basin. The oil seepages are accompanied by significant gas leakage. The zone between the Dongsheng gas field and the Wulangar Uplift is therefore likely to have very good accumulation and preservation conditions and may offer a promising exploration prospect for natural gas.

Impact of sanctions on the development of the gas industry in Russia

The relevance of the study is conditioned by the following facts. The gas industry is an important structural component of the Russian economy. It not only contributes significant funds to the federal budget, but also affects economic growth rate, production potential, and development of scientific and technological progress. In the situation when anti-Russian sanctions are imposed, it becomes necessary to preserve the revenues received, projects underway and switch to new markets, analyzing the totality of risks that companies may face. In this regard, it is particularly important to study impact of sanctions on the Russian gas industry development and prospects for it in the current realities. The subject of the article is main trends in the gas industry development under sanctions. The purpose of the research is to study the specifics of the sanctions impact on the Russian gas industry development. The methodology used was the analysis of Internet resources corresponding to the research topic, statistical data, its synthesis, and generalization. The main results of the research are studying trends, specifics and prospects for the gas industry development in the context of introducing anti-Russian sanctions and defining the sanctions risk as one of the most important ones. The results obtained can be applied in assessing future development trends of the Russian gas industry considering the current situation, as well as in educational process. The prospects for further research on this topic include studying specifics of various risks impact on the Russian gas industry development and forming recommendations for hedging and managing them.

Exploration for Helium in the Phanerozoic

Almost all the helium discovered worldwide has been found by chance in the drilling for hydrocarbons. Targets were usually anticlinal structures located by seismic surveys. The association of helium and natural gas in reservoirs is purely coincidental because the source rocks for each are different—natural gas is mainly produced from diagenesis of carbon rich shale whereas Helium- 4 is derived mainly from the decay of uranium/thorium in the crust. A new geochemical exploration system for helium in the Phanerozoic is considered highly desirable by industry. The current exploration system in the Phanerozoic uses a modified petroleum system concept that has been used successfully for decades to high-grade plays and de-risk oil and gas prospects. Like a petroleum system, the helium system is identified by its source rock, reservoir, trap, seal, and migration pathways. However, this approach is expensive taking years to complete and can be a limiting factor for countries/provinces/states to develop their resources. As a precursor to ground helium/hydrogen surveys for exploration in the Phanerozoic, hyperspectral (satellite) surveys assess huge areas for their helium potential as well as any associated hydrocarbons. These areas may be even devoid of any previous exploration for hydrocarbons. This is followed with geochemical soil gas surveys of the more prospective trends to locate drilling locations. Both methods ascertain whether helium anomalies, which represent helium reservoirs at depth, are associated with hydrocarbons or nitrogen. Helium reservoirs associated with nitrogen are higher in helium content but are deeper, close to the basement. Hyperspectral and geochemical soil gas surveys are also applicable for projects that begin with helium analysis of old wells followed by seismic and drilling. Typically, exploration companies lease vast areas surrounding the legacy well, but their initial focus is on seismic in the area around the legacy well to determine the size and configuration of the helium reservoir and trap penetrated by the well and this is followed by drilling. It is not known at this point whether this reservoir is the best prospect because the helium discovered is usually associated with hydrocarbon (HC), not with nitrogen with much higher helium concentration in the lower Phanerozoic. Rarely do legacy wells penetrate deep enough to this level. Any cost-effective exploration program for helium is best accomplished by hyperspectral and follow-up geochemical soil gas surveys.

Earth crust of eastern segment of Ukrainian Carpathians in the regional profile RP-5 zone: structure, geodynamics, oil and gas bearing

The purpose of the work is to present widely to the scientific community and analyze in detail the structure and oil and gas bearing of the Bukovyna lithosphere (the eastern part of the Carpathian region of Ukraine) based on the unique data on the regional RWМ-CDP profile RP-5 and on the neighboring regional profiles with the involvement of other geological and geophysical data. The methodology includes a detailed comprehensive analysis of the deep structure and oil and gas bearing and oil and gas prospects of the region and its separate zones based on seismic data on the regional profile RP-5 and nearby oil and gas bearing and oil and gas prospective areas with the involvement of a complex of geological and geophysical data. Results. In the zone of the profile RP-5, the occurrence of sedimentary strata and covers of the Folded Carpathians, the Carpathian foredeep and the edge of East-European craton in the earth's crust of Bukovyna was traced in detail, including the different depth tiers of the Carpathian thrusts and folds. The stepwise dipping of the edge of the East-European craton below the Carpathians is revealed here (generally similar to other segments of the Ukrainian Carpathians). The presence here of weakly dislocated autochthonous layers of Mesozoic rocks under the Carpathian thrusts is also established. In these horizons, several bands of folds of the Carpathian extension were discovered, some of them, in particular, the Lopushna fold, are associated with discovered oil and gas deposits. The thickening of the horizons of the lower crust under the axial part of the Bukovyna Folded Carpathians was revealed. In the pre-Carpathian part of the profile, there are 2 deepped ancient "seismofocal" zones of different age of formation and different vergence (researched in detail by S.G. Slonytska using special methods), as well as a number of apophysis-like intrusions. As a result of the comprehensive analysis, the influence of the characteristic features of the local Alpine geodynamic process was traced – the Alpine/Carpathian compression of the lithosphere in the northeast direction orthogonal to the Carpathians and the corresponding thrusts of the allochthon on the previously stepwise dipped here in the southwest direction western edge of the East-European craton as a result of rift-like pre-alpine geodynamic processes. Originality. The peculiarities of the deep structure, geodynamics, seismicity and oil and gas bearing of the Bukovyna lithosphere were determined based on the data of the regional profile RP-5, taking into account new data from oil and gas exploration studies in the subregion and data on various components of the geodynamic process in the whole Carpathian region of Ukraine. The oil and gas prospects of a number of deep folds of autochthonous Mesozoic rocks in the subthrust of the Pokuttya-Bukovyna Carpathians have been predicted and confirmed. Practical significance. The research results make it possible to more clearly justify the directions of oil and gas exploration in the subregion.

Organic matter enrichment in shale deposited proximal to paleo-uplifts and its impact on shale gas exploration

Much of the global exploration and development of shale gas is focused on organic-rich shale deposited in basin or slope/basin margin settings. There is a clear need to assess the degree to which organic-rich shale deposited in other settings, notably proximal to paleo-uplifts, are promising shale gas prospects. Organic-rich sediments that accumulated proximal to paleo-uplifts are recognized globally and include the Cambrian Niutitang Formation, Ordovician-Silurian transition “hot shales”, and modern sediments of the Black Sea. Though the subject of recent research efforts, much remains to be learned of the mechanisms of organic matter enrichment of fine-grained sediment deposited adjacent to paleo-uplifts. Our study focuses on the Ordovician Wufeng Formation that accumulated proximal to uplifted areas of the Upper Yangtze platform. Though the TOC content of the analyzed Wufeng Formation samples recovered from near the paleo-uplifts is less than that of Wufeng samples collected from basin or slope/basin margin settings, average TOC value of the former can still reach more than 2%. Wufeng Formation shale deposited proximal to paleo-uplifts accumulated under conditions of medium to high paleoproductivity, elevated terrigenous clastic input and sedimentation rate, and oxic-suboxic water column conditions. Principal component analysis suggests that the factor most critical to organic matter enrichment of Wufeng deposits proximal paleo-uplifts was paleo-redox conditions. The TOC abundance in Wufeng Formation shale deposited during late Katian stage is higher than that of shale deposited during Hirnantian stage. It was at the Hirnantian stage that the paleo-uplifts became most active in association with the Kwangsian Orogeny resulting in diminished paleoproductivity and preservation conditions as reflected in the reduced organic matter abundance of associated shale. Uplift of the paleo-uplift of the Yangtze Platform, a manifestation of the Kwangsian Orogeny during the Ordovician-Silurian transition, appears to have been largely responsible for spatial and temporal distribution differentiation of organic matter abundance of the Wufeng Formation of the Upper Yangtze Platform. Results of the present study contribute supplementary information regarding the mechanism of organic matter enrichment in shale and can provide guidance for shale gas exploration and development in geologically similar regions.

Application of 13CH4 double model online analysis method based on Fourier Transform Infrared Spectroscopy in energy exploration

In the last decades, the substantial demands for 13CH4 detection in oil, natural gas, and geological prospecting have been increasing. Among the commonly used gas detection methods, Fourier Transform Infrared Spectroscopy has the advantages of a short detection cycle and simultaneous detection of many gas components, but it has not been realized for the online analysis of 13CH4. In this paper, we propose a double model analysis method for 13CH4 concentration based on Fourier Transform Infrared Spectroscopy. This method uses a Fourier Transform Infrared Spectrometer to obtain infrared absorption spectra of gases containing 13CH4. It corrects the drift of the spectral baseline using the adaptive smoothness parameter penalized least square method. In addition, aiming to have a more fine-grained result, we categorize the volume concentration into two intervals (1 ×10−6-0.5 % and 0.5 %–100 %) for quantitative analysis, and combine a Novel Frequency control and Regression Coefficients method for characteristic variable extraction and quantitative analysis modeling to exclude the effect of other alkane gases on 13CH4 detection. We conducted a series of experiments and the results demonstrate that our proposed double model analysis method is capable of fast 13CH4 detection from mixed gas with a detection error lower than 2 % and a detection cycle shorter than 12 s for the concentration ranges from 1 × 10−6 (1ppmv) up to 100 %. Finally, we have accurately analyzed the 13CH4 content in the gas-producing formation from oilfield logging experiments.

Landfill Gas Prospect as a Renewable Energy Source at Talang Gulo Jambi City, Jambi Province, Indonesia

Landfill Gas Prospect as a Renewable Energy Source at Talang Gulo Jambi City, Jambi Province, Indonesia

Research on Oil and Gas Energy Cooperation between China and Central-North Asian Countries under the “One Belt and One Road” Strategy

The “One Belt and One Road” strategy provides a new opportunity for deepening oil and gas energy cooperation between China and Central-North Asian countries. This paper systematically studies the supply and demand characteristics, interdependence and cooperation prospects of oil and gas between them using relevant oil and gas energy data of these countries from 2016 to 2021. The objective of this research is to provide a basis for the overall planning of oil and gas energy cooperation between China and Central-North Asian countries in the future. The results show that the proven reserves of oil and gas in Central-North Asian countries are high; particularly, the proven reserves of natural gas account for 30% of the world. These countries also have high oil and gas self-sufficiency rates. These have laid a material foundation for China to strive for the sustained and stable import of oil and gas energy from Central-North Asian countries. At the same time, there are great imbalances in oil and gas reserves, production, consumption, available exports and their growth rates among Central-North Asian countries, which provide a basis for China and Central-North Asian countries to make strategic decisions on oil and gas energy differential cooperation. China imports 80 × 106 tons of oil and 490 × 108 cubic meters of gas from Central-North Asian countries every year and Chinese dependence on oil and gas imports in this region is 16% and 37%, respectively. The study believes that China has certain potential to increase the import of oil and gas from Central-North Asian countries and has good prospects for oil and gas cooperation. It is proposed that China should give priority to increasing oil and gas exploration and development cooperation with Central-North Asian countries with high oil and gas reserve–production ratios, and should strengthen oil and gas resource trade cooperation with Central-North Asian countries with high oil and gas self-sufficiency rates. At the same time, China should increase investment and cooperation in the midstream and downstream business of the oil industry in major Central-North Asian countries through various financing channels. China should uphold the principle of win–win cooperation to promote the in-depth and steady development of oil and gas energy cooperation between China and Central-North Asian countries.

Structure and genesis of the Achimov olistostromic strata of Western Siberia

The question of the genesis of the anomalous Bazhen-Achimov zones remains to be one of the most controversial problems in Western Siberia. By now, about dozen hypotheses of the sedimentary environment of this specific formation have been proposed. However, none of these hypotheses is generally accepted. All hypotheses have been classified by genesis and their critical analysis is given in the article. The solution is closely related with experience of the geological exploration works, since the prospects of oil and gas are associated with these deposits. The article highlights the key features of the structure of the anomalous section’s zones based on drilling and seismic data. The classification of the hypotheses is given and the features of sedimentation in the Bazhenov and Achimov times are highlighted. An accumulated data has allowed us to substantiate the olistostromous genesis of the anomalous section. Based on a set of data, including paleogeographic, sedimentological, paleotectonic reconstructions, a principal detailed model of the sedimentary environment of olistostromes is proposed for the first time. The proposed model seems to be the most logical, supported by the actual data known to date, is the most universal and fits into the paleogeographic situation and tectonic regime that prevailed in the Achimov time.

Topical issues of legal regulation of gas production in Russia

The prospects for natural gas on the Russian continental shelf are very significant. According to experts, there are about 55 trillion cubic meters of natural gas on the Russian continental shelf. Most of these reserves are concentrated in the Yamalo-Nenets Autonomous Okrug, where approximately 43.5 % of the total reserves of the Arctic shelf are located. There are also significant reserves of natural gas in other parts of the Arctic shelf, such as the Barents and Kara Seas. Despite the rather complete regulatory framework that governs all stages of natural gas production, from obtaining a license to the environmental component, the system of regulatory legal acts in the field of gas production can be described as quite complex and multi-level. The article deals with the issues of legal regulation of production and processing of natural gas associated with new political and economic challenges. The authors conclude that further systematization of legislation in this area.