Gas Prospects Research Articles

ГЕОЛОГИЧЕСКИЕ ПРЕДПОСЫЛКИ ПОИСКОВ ЗАЛЕЖЕЙ НЕФТИ И ГАЗА В СТРАТИГРАФИЧЕСКИХ И ЛИТОЛОГИЧЕСКИХ ЛОВУШКАХ ЮГО-ЗАПАДНОГО БОРТА НИЖНЕКУРИНСКОЙ ВПАДИНЫ

The Lower Kura depression is a recognized oil and gas generating basin, characterized by positive stratigraphic, lithological-facies and structural-tectonic criteria for oil and gas content. However, it is necessary to additionally assess the prospects for oil and gas content of the southwestern side of the basin, guided by the criteria for the presence of reservoirs, seals and traps, paleotectonic criteria and seismic geological indicators.According to the results obtained from a detailed study by geophysical methods of the Kyurovdag-Neftchala belt and the territories framed to it, it was found that developed lithologically limited and stratigraphic traps in the Sarkhanbeyli, Orta Mugan, Shargi Shorsulu and Babazanan areas have all the signs of oil and gas prospects. These traps are located at a depth of no more than 4.5 km between the Mesozoic paleorelief protrusions and the Pleocene sediments covering them. It was the disagreement between these rocks that played an important role in the migration and accumulation of hydrocarbons. It should be noted that the traps formed in the process of sedimentation by primary reservoirs above the unconformity surfaces are sedimentation-stratigraphic and adjacent to the unconformity surface. Studies have revealed similar traps in deeper pinching horizons, which can be considered promising in terms of the development of reservoirs, cap rocks and oil-damaging reservoirs.

What prospects for shale gas in Asia? Case of shale gas in China

Abstract The issues of energy and the environment are one of the main challenges for humanity today. Global growth in energy demand is facing environmental concerns, especially in fast-growing regions such as Asia. Transferring traditional energy sources such as coal, oil, to cleaner energy sources and renewables is an inevitable trend in the future. With good characteristics compared to other fossil fuels, natural gas can play an essential role in the energy transition process towards a low-carbon economy. The success of the shale gas revolution in the USA has created a lot of interest globally, especially in countries with potential for these resources. Asia, especially China, is estimated to have the world's largest shale gas resource. However, the question about the development of these resources is still a big question. This article will evaluate shale gas development prospects in Asia, particularly in China, by analysing the fundamental conditions that are important factors for the success of shale gas in the USA.

The Arctic policy of the Republic of Korea

Nowadays the Arctic attracts a lot of countries all over the world, including Asian ones, due to its features, especially its abundant resources and research potential. In the paper the authors consider the Arctic policy of the Republic of Korea. Shipping and sea trade, oil and gas prospection, scientific research are of particular importance for South Korea. International cooperation with the circumpolar states and protection of indigenous people and nature preservation are also essential for the country. To achieve these goals the government of the state has designed several policy documents which provide the authors with the information for this research.

ДИНАМІКА РОЗВИТКУ ЛІТОФЛЮЇДНИХ НАФТОГАЗОВИХ СИСТЕМ У КРЕЙДОВИХ ВІДКЛАДАХ ЗАХІДНОЇ ЦЕНТРИКЛІНАЛІ ПРИЧОРНОМОРСЬКОГО МЕГАПРОГИНУ

On the basis of modeling the dynamics of the catagenesis of the Cretaceous deposits, the lateral heterogeneity of the history of their catagenesis within the western part of the Black Sea megadepression, caused by the tectonic regime of the blocks separated by the Golitsyn, Sulino-Tarkhankutsky, Gubkino-Donuzlavsky sublatitudinal faults, was established. The spatio-temporal features of the development of reservoirs and migration paths of hydrocarbon fluids have been established, the predicted zones of oil and gas accumulation have been localized. There are four types of lithogenetic reservoirs, which differed in the time of formation, structural features, fluid regime and the nature of oil and gas saturation.In the first cycle of catagenesis, the generation center was localized mainly in the sediments of the Lower Albian (t 80–100 оС), in the second – the Middle Albian (t 100–120 оС), in the third – the Upper Albian (t 130–150 оС).Given a certain difference in the situations of sedimentation of these stratigraphic units, the composition and content of scattered organic matter in the sediments were different. This, as well as the different generation temperatures, obviously caused the specific composition of hydrocarbon fluids formed during individual cycles of catagenesis. Along the migration pathways and during structural changes, these fluids were mixed, multicomponent systems were formed, and the composition of hydrocarbons changed.The possibility of the existence of subvertical "vein" areas of oil and gas accumulation with a width of up to 10 km and a height of 1,5–2,0 km is argued. Such reservoirs, on the one hand, may contain deposits and, on the other hand, supply hydrocarbons to overlying traps. Given the nature of oil and gas accumulation, the potential resources and, consequently, the prospects for oil and gas in the region can be much higher.

Application analysis of shale gas core hyperspectral in weican-1 well

Hylogger core scanning system is used to detailed scan shale gas drilling cores, obtaining visible-near infrared (spectral range 380nm-1100nm),short-wave infrared (spectral range 1100nm-2500nm) spectral curves and high-definition core images. Taking Well weican 1 in the West Taikang Uplift in the South China North Basin as an example, based on the analysis of clay mineral types in the core of the target layer, it is judged to be an alkaline deposit environment rich in iron and magnesium with a temperature of about130°C. Combined with mineral information and core image, the core of the target layer is divided,mud shale is developed, the cumulative thickness exceeds 400m, the maximum single layer thickness reaches 38m, at the same time, the hydrocarbon absorption characteristics of the shale section are obvious, it shows a good prospect for shale gas in the region.

О РЕЧНОЙ СЕЙСМОРАЗВЕДКЕ: ИСТОРИЯ, ОПЫТ ПРИМЕНЕНИЯ, ВОЗМОЖНОСТИ НА СОВРЕМЕННОМ ЭТАПЕ ИССЛЕДОВАНИЙ СИБИРСКОЙ ПЛАТФОРМЫ

Since the beginning of the 2000s, water shooting has been carried out on the territory of the Siberian Platform o a number of profiles, including long routes along the Nizhnyaya Tunguska [Lower Tunguska] River, Lena River (in the upper and lower courses), Vitim River, as well as more local works, including experimental and methodological ones – at the Angara, Chuna, and Biryusa Rivers. The high geological efficiency of these routes, combined with an almost twofold reduction in the cost of one linear km of seismic profile, сomparatively common ground-based operations of the CDP method, allows researchers to recommend the expansion of such operations on the rivers of the northern Tunguska syneclise, the area with very low exploration degree of prospects of oil and gas. It is situated in the region where a quarter of all the hydrocarbon resources of the Siberian Platform are on the balance sheet.

Geological and Bioregional Assessments: assessing the prospectivity for tight, shale and deep-coal resources in the Cooper Basin, Beetaloo Subbasin and Isa Superbasin

The Geological and Bioregional Assessment Program is a series of independent scientific studies undertaken by Geoscience Australia and the CSIRO, supported by the Bureau of Meteorology, and managed by the Department of Agriculture, Water and the Environment. The program consists of three stages across three regions with potential to deliver gas to the East Coast Gas Market. Stage 1 was a rapid regional prioritisation conducted by Geoscience Australia, to identify those sedimentary basins with the greatest potential to deliver shale and/or tight gas to the East Coast Gas Market within the next 5–10 years. This prioritisation process assessed 27 onshore eastern and northern Australian basins with shale and/or tight gas potential. Further screening reduced this to a shortlist of nine basins where exploration was underway. The shortlisted basins were ranked on a number of criteria. The Cooper Basin, the Beetaloo Subbasin and the Isa Superbasin were selected for more detailed assessment. Stage 2 of the program involved establishing a baseline understanding of the identified regions. Geoscience Australia produced regional geological evaluations and conceptualisations that informed the assessment of shale and/or tight gas prospectivity, ground- and surface-water impacts and hydraulic fracturing models. Geoscience Australia’s relative prospectivity assessments provide an indication of where viable petroleum plays are most likely to be present. These data indicate areal and stratigraphic constraints that support the program’s further work in Stage 3, on understanding likely development scenarios, impact assessments and causal pathways.

Гидрогеохимические критерии поиска и разработки углеводородных месторождений: обзор, анализ и перспективы использования на острове Сахалин

The paper discusses the directions of hydrogeochemical researches used to solve actual problems of the oil and gas industry: assessment of the oil and gas potential of territories, localization of oil and gas trap, prediction of the phase composition of hydrocarbon fields, control the development process of hydrocarbon fields, etc. Based on the literature data, the analysis and systematization of the main hydrogeochemical indicators of groundwater with oil and gas prospecting significance, as well as used already at the stage of development of oil and gas fields, have been carried out. The most efficiency of the application of hydrogeochemical researches in oilfield practice is achieved with the integrated use of various indicators. On the example of researches of the oil and gas potential of Sakhalin Island, it is shown that the hydrogeochemical data of the middle of the 20th century, obtained by outdated chemical analytical methods, cannot always be considered reliable. In this regard, additional researches are required to update the relevant hydrogeochemical data in this region.

On the stratigraphy and tectonics of Zilair synclinorium of the Urals

The purpose of the work was to study the tectonic structure of the Zilair synclinorium of the Western slope of the southern Urals, which is important both from the general scientific point of view and for the needs of oil and gas prospecting of the territory. The main method of research was a detailed study of the stratigraphy of key sites with the search for conodonts in siliceous rocks. We also used data from seismic profiling of the territory. Result of work. The Zilair synclinorium of the southern Urals is an asymmetrically different facies structure; its Western and Eastern wings are composed of deposits belonging to different facies zones – the shelf (neritic) in the West and the continental slope and rise (bathyal) in the East. In the axial zone of the synclinorium, among the Famennian graywacke deposits of the Zilair series, several sites composed of cherts are known. It was believed, that the cherts are of Silurian age and are the klippes of a very large overthrust belonging to the ophiolite association. According to occurences of conodonts, we have established that all these cherts have Devonian, mainly Frasnian age. They are not klippes of an overthrust, but the central parts of the anticlinal folds, complicated by steep thrusts. According to our data, the real overthrust with a great horizontal amplitude is Pokrovsky, where two facial zones come into an abrupt contact without any transition between them.

Hydrocarbon Generation Potential of the Campano-Maastrichtian Dark Mudstone Lithofacies, Benin Flank, South West Anambra Basin, Nigeria

The dark mudstone lithofacies of Mamu Formation was deposited during the Campano-Maastrichtian flooding episode. It is laterally heterogeneous, and has been subdivided into marsh, bay and central basin subenvironments in order of proximality. Arising from recommendation from a previous study, we evaluated its hydrocarbon generating potential using multidisciplinary tools involving visual kerogen analysis, as well as bulk and isotope geochemistry. Seventy-seven sample materials were taken from 3-outcrop sites at Uzebba, Okpekpe and Imiegba locations, Benin flank, SW Anambra Basin, Nigeria. The results show that bulk of the samples have good organic richness. Kerogen quality is dominantly of gas prone Type III kerogen. However, visual kerogen analysis indicates the presence of an oil prone Type II/III kerogen in the central basin subenvironments. An immature thermal maturity is inferred based on spore colour index (SCI) of less than 6 on the SCI chart (thermal alteration index of <2.5). In addition, we hypothesize that the dark mudstone lithofacies possesses biogenic gas potential based on its organic richness, kerogen quality and thermal maturity. Shale gas prospectivity is further enhanced by the low dip of the Mamu Formation, shallow burial as well as high silica content. Worth mentioning is the proximal marsh mudstone (Uzebba location) with suitable microfabric, very high silica as well as >10m of combined (continuous) outcropping and subcropping thickness
 Keywords: Kerogen, palynofacies, stable isotope geochemistry, shale gas,

Ultra-deep oil: comparison of oil and gas bearing basins and prospects for exploration for ultra-deep deposits (Sichuan, Tarim, Permian, Canning and Precaspian basins)

The article reviews information on oil and gas bearing basins, where considerable experience has been accumulated in the geological study and development of the so-called ultra-deep oil and gas deposits (depths over 6000 m), on the geological structure, discoveries within the considered oil and gas basins, data on wells drilled to great depths, including test results, reservoir fluids reserves and properties.

Evaluation of shale gas reservoirs in complex structural enclosures: A case study from Patala Formation in the Kohat-Potwar Plateau, Pakistan

Breakthroughs in shale gas exploration and production technology in China point to a possible solution to Pakistan's current energy crises. In this study, we evaluate the shale gas prospects in the Kohat-Potwar Plateau of Pakistan by establishing an integrated approach involving the analysis of fundamental elastic and petrophysical properties, Rock-Eval pyrolysis, and the sealing mechanism of shale. Detailed geochemical and petrophysical evaluation of the Patala Formation in the Kohat-Potwar Plateau indicates the good potential for shale gas with the following characteristics similar to the Longmaxi shale of Sichuan Basin China, i.e., (i) complex structural types sandwiched by tight limestone strata with low porosity (less than 3%), ultra-low permeability, high density, and large thickness which provides strong sealing capacity for gas preservation and enrichment; (ii) multiphase tectonic evolution of Patala Formation allowed various slippage processes to develop fractures and enhance the porosity and permeability; (iii) high organic matter content and thermal maturation stage (TOC > 2%, 416–445 °C); (iv) high brittle minerals content (e.g., calcite and dolomite > 40%); and (v) large formation thickness (>30 m) at shallow burial depth < 2500 m. This study emphasizes the critical role of the sealing mechanism in shale gas reservoirs. Furthermore, the results suggest that the evaluation and development of shale gas potential using petrophysical and geochemical analysis may be inadequate. Further scrutiny of the roof and floor of reservoirs' efficient sealing capacities is essential to understand the extent of shale gas preservation and enrichment. The study results provide valuable insights for identifying the sweet spots and preservation condition of shale gas in the Kohat-Potwar Plateau of Pakistan.

Offshore disputes and weaker demand shake East Mediterranean gas prospects

Oil and Energy TrendsVolume 45, Issue 11 p. 9-15 SURVEY Offshore disputes and weaker demand shake East Mediterranean gas prospects First published: 27 November 2020 https://doi.org/10.1111/oet.12825Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Volume45, Issue11November 2020Pages 9-15 RelatedInformation

Shale gas prospect of different source rock types from Early Maastrichtian Mamu Formation, Anambra Basin, Nigeria

The gas prospect of three identified source rock types from the Early Maastrichtian Mamu Formation of the Anambra Basin, Nigeria was evaluated by thermal simulation, followed by gas composition analyses of the generated hydrocarbons. The amounts of C1 and ΣC1-5 generated at the highest examined pyrolysis temperature of 480°C (Easy Ro of 3.27%) range from 3.52 to 32.00 ml/g rock and 4.08 to 43.44 ml/g rock, respectively. The sub-bituminous coal has the highest gaseous hydrocarbon generative potential up to late gas generation stage, followed by carbonaceous shale while shale has the least productive capacity. The recovery of gaseous hydrocarbons may be influenced by the ratio of TOC to clay content in all the source rocks. The gas dryness index indicates that the shale is the driest among the source rock types.

Прогнозирование нефтегазоносности южной части Пермского края с использованием регионального трехмерного моделирования

The territory of the southern part of Perm Krai is well studied in terms of oil and gas prospecting. About 150 oil and gas fields have been discovered there, over 7000 deep wells have been drilled, and 3D seismic surveys have been completed on the area exceeding 5000 km2. The state of exploration of the territory allows us to have an immense array of geologic information, which can be used to search and predict oil and gas occurrence in structures that remain left out or that have not been studied yet. The research area was limited by the confines of Perm Krai in the south, west, and east and by a conventional line in the north along the boundary of the completed seismic surveys. To study the territory based on the reflecting horizon surface of Perm Krai, a 3D geological model has been built within IRAPRMS software system. The model calculates a regional, a zonal and local constituents of the reflecting horizon of Perm Krai. The local constituent allowed us to single out structures divided into three categories: structures of ascertained oil and gas occurrence, structures that do not contain oil and gas (empty), and structures for which a prediction is needed. In the model, structural parameters representing a trap potential for the accumulation and retention of hydrocarbons were calculated. Moreover, geochemical parameters showing a generation potential and a migration constituent, as well as hydrogeological parameters as indirect data to determine the saturation of structures with hydrocarbons, were downloaded into the model. The obtained data about the importance of each parameter for all structures allowed us to generate a single database and predict oil and gas occurrence by the machine learning method, i.e. through the step-bystep linear discriminant analysis. Based on the results of the linear discriminant analysis, 138 predicted structures were arranged in groups in accordance with degrees of their potential. By applying the built individual probability models, a map of the regional probability of structures’ saturation with hydrocarbons was obtained; this map served as a basis and amendment of oil and gas geological zoning boundaries of the southern part of Perm Krai.

Long-range role of natural gas in the EU green transition: analytical overview

Pan-European and national policy documents were reviewed that set the goals for the development of the European economy and energy. The objective of this paper is due to changes in European policy vision of the natural gas’s future prospects of in the context of establishing strict climatic requirements and the desire to achieve a carbon-neutral level of the European economy development. In previous periods, it was believed that until the 2040s-2050s we can expect the “Golden Age” of natural gas, which was due to the success of the revolution in the United States, significant expectations of a repeat of the US success of shale gas production in other parts of the world, increased transportation of natural gas by pipelines and LNG tankers; decreased growth rate of a nuclear energy and further cost reduction of a shale gas production. A change in the European energy policy towards the strengthening of environmental requirements, reduction of greenhouse gas emissions and emerging of EU's role in combating climate change causes uncertainties regarding prospects of natural gas as an energy resource in Europe. By choosing the European vector of development, Ukraine is interested in meeting requirements of EU policy within the framework of its international obligations and European integration ambitions. This makes it necessary to adapt national development programs and strategies to new conditions and challenges that arise in the EU. The analysis of the main EU policy documents on prospects for the natural and other synthetic gases development allows us to begin to reassess national development plans for adapting the internal developed gas infrastructure to new market opportunities, which will permit Ukraine to increase its competitiveness in the gas market further, and consumers will be able to receive energy resources at more competitive prices and an appropriate quality of service. The complex of problematic issues that arise in the EU member states regarding the formation of incentives for the introduction of synthetic, green gases, adoption of appropriate regulatory mechanisms, formation of effective financial mechanisms that would attract investment in the development of a new infrastructure or development of new technologies requires from Ukraine to define priorities of its economic development, to form a roadmap for the energy system transformation in accordance with new international requirements, internal needs and economic opportunities to implement corresponding technological transformations. The central government after consultations with interested participants in the energy market should form a nationwide vision of the vector for the energy sector development in Ukraine and the place of natural gas in the energy supply of Ukraine until 2050.

New geodynamics and oil-and-gas geology zoning of the Caspian megadepression for oil and gas prospects assessment

New geodynamics and oil-and-gas geology zoning of the Caspian megadepression for oil and gas prospects assessment

Effect of Surface Force on Nanoconfined Shale-Gas Flow in Slit Channels

Summary A model for gas transport in nanoscale channels in shale-gas reservoirs (SGRs) is proposed using a new effective mean free path (MFP) model, which considers the effects of surface/gas interaction and the geometrical termination of a nanochannel boundary. In addition, the influences of the nanochannel dimension, formation-burial depth, surface type, and gas type on nanoconfined gas flow in slit channels are addressed. The nanoconfined gas-flow behavior is investigated for a wide range of temperature and pressure in this work because of the large prospects of shale gas in deep and ultradeep formations with pressure up to 100 MPa and temperature up to 480 K. The newly developed effective MFP model and the gas-flow-rate model are successfully validated with data from molecular dynamics (MD) simulations and experiments. Results show that the effect of surface force reduces the MFP and gas-flow capacity, which increases with a decreasing pressure, a decreasing channel size, and an increasing temperature; that the nanoconfinement effect has weaker influence on gas-transport capacity as the formation-burial depth increases and greater influence as formation pressure decreases during hydrocarbon production from SGRs; that a surface type affects the gas transport, and the gas-flow capacity in carbon (C) channels (organic channels) is stronger than that in silicon (Si) channels (inorganic channels) with the same size; and that the differences among the transport capacities of nitrogen (N2), argon (Ar), and methane (CH4) are not obvious, while the transport capacities of helium (He) are greatly lower compared with CH4 at both the SGR temperature and the laboratory temperature.

Effective hydrocarbon-bearing geological conditions of the Permian strata in the South Yellow Sea Basin, China: Evidence from borehole CSDP-2

For nearly 60 years, petroleum geologists have been puzzled by oil and gas exploration in the South Yellow Sea basin, which is considered to have broad oil and gas prospects, but no commercial hydrocarbon reservoirs have been obtained. The hydrocarbon-bearing geological conditions of the Permian strata with good exploration prospects also have never been systematically investigated. To solve the problem, a series of experiments was conducted on core samples obtained from borehole CSDP-2, the first exploration well with continuous coring in the South Yellow Sea Basin, including petrology analysis, geochemical testing, pore-throat testing, hydrocarbon-charging analysis, and sealing-ability evaluation. Vitrinite reflectance (Ro), total organic carbon (TOC), pyrolysis, extractable organic matter (EOM) and kerogen microscopic examination were carried out to evaluate the quality of the Permian source rocks. Porosity, permeability, thin section, scanning electronic microscopy (SEM) and rate-controlled mercury injection (RCMI) analyses were combined to verify the effectiveness of sandstone reservoirs. The sealing capacity of caprock was mainly evaluated by the displacement pressure. And according to the fluid-inclusion analysis and oil-source correlation, the hydrocarbon accumulation events were determined. After comprehensive analysis, we clarified the effective hydrocarbon-bearing geological conditions and favorable prospects in the Permian of the South Yellow Sea Basin. Furthermore, the main controlling factors pertaining to favorable source rocks and tight sandstone reservoirs were ascertained in this paper.The results show that two sets of the Lower Permian Qixia and Gufeng Formation (P1q-g) and the Upper Permian Longtan and Dalong Formation (P2l-d) source rocks, along with the P2l-d tight sandstone reservoirs, compose two types of hydrocarbon accumulation assemblages, which are effectively sealed by the Lower Triassic Qinglong Formation (T1q) roof caprock. One type represents the ‘lower-generation and upper-accumulation’ between the P1q-g source rocks and the P2l-d sandstones, and the other type represents the ‘self-generation and self-accumulation’ in the Upper Permian strata. Vertical stacking between the Permian source rocks and sandstone reservoirs ensures the near-source hydrocarbon accumulation, and faults and microcracks can be regarded as beneficial channels for hydrocarbon migration. In addition, we find that the quality of source rocks is improved by large-scale marine transgression, high bio-productivity, and tectonic–thermal events. The quality of tight sandstone reservoirs is more dependent on throats with relatively larger radius than pores. This study provides important enlightenment for exploring marine hydrocarbons in the South Yellow Sea Basin, and can be useful in understanding the dominant geological factors affecting favorable source rocks and sandstone reservoirs.

A consequence analysis study of natural gas consumption in a developing country: Case of India

Natural gas, as the cleanest burning of the fossil fuels is expected to play a significant role in India's future energy mix. This paper presents a modelling approach to quantify the economic and environmental impacts of natural gas utilisation by various sectors in India while the production of domestically sourced natural gas is in decline. One of the most important sectors is the use of natural gas for cooking where the benefits are also evaluated. The long-term impacts of a reducing domestic gas supply is assessed by using the resource-substitution methodology along with a dynamic resource-depletion indicator that is based on decision-making viewpoints. The results show that the replacement of domestic gas with black coal resulted in an increase under the climate change category by 162%, 202% and 234% for the individualist, hierarchist and egalitarian viewpoints, respectively. The paper highlights the prospects for natural gas in India and shows that the growing demand for gas can be met through imports, but it has associated economic and environmental impacts. Further, the paper presents suitable recommendations including policy-related changes such as carbon pricing and subsidy provision schemes to ensure that the growth of the Indian gas market is sustainable.