HYDROCARBON SIGNIFICANCE OF UPPER PALAEOZOIC SEDIMENTS ASSOCIATED WITH THE KOBURRA TROUGH, GALILEE BASIN

1974 ◽  
Vol 14 (1) ◽  
pp. 59
Author(s):  
R. J. Allen

The Koburra Trough is a major tectonic feature in the northeastern Galilee Basin of Queensland. The oldest rocks identified in exploratory drilling were Devonian sandstone, shale and siltstone, possibly representing a northern extension of the Adavale Basin. These rocks contain a fossil microflora and may be prospective for hydrocarbons. Overlying them are a maximum of 1979 m of Upper Palaeozoic sediments, and a maximum of 1180 m of Triassic sediments, together comprising the Galilee Basin succession. The lithofacies of the Late Palaeozoic is dominantly sandstone-shale; the lower beds show evidence of glacial derivation, and the upper beds contain coal measures. Shows of oil and gas have been recorded from the basal part of the sequence in the two deep wells (ENL Lake Galilee −1 and FPN Koburra −1) drilled in the trough. Structural and stratigraphic factors favour the existence of hydrocarbon traps on the south-western flank. "Large" inferred reserves of Upper Permian sub-bituminous coal have been discovered in Geological Survey exploration near outcrop at the southeastern end. Preference in the use of this coal is to be given to manufacture in Queensland of synthetic fuels and petrochemicals. The geological survey petroleum statigraphic drilling campaign is providing invaluable new data on the Galilee Basin.

2021 ◽  
pp. M57-2017-23
Author(s):  
E. Henriksen ◽  
L. Kvamme ◽  
T. A. Rydningen

AbstractThe Hammerfest Basin is an E -W trending graben located between the Loppa High and the Finnmark Platform in the southern part of the Norwegian Barents Sea. Mainly siliciclastic strata of Carboniferous to Cenozoic age cover the Caledonian basement and have a total estimated thickness of 5-8 km. The basin evolved through several tectonic phases: the Carboniferous rifting, Late Jurassic rifting, the opening of the Atlantic Ocean, Oligocene reorganisation of plate movements and postglacial isostatic rebound. An E-W trending dome in the centre of the basin developed during the main extensional tectonic event in Late Jurassic. Horst structures represent the main hydrocarbon traps. Erosional channels on the flanks of the basin represent entry points for Lower Cretaceous sands. For the rest of the Cretaceous and Cenozoic intervals no significant reservoir sands are expected.The first exploration well in the Barents Sea in 1980 was located in the Hammerfest basin, and by 2019 a total of 45 wells had been drilled in the basin where 34 are classified as exploration wells. The result is 18 oil and gas discoveries, which gives a discovery rate of 53%. Two fields are now in production: the Snøhvit gas-condensate fields and the Goliat oil field.A total of 340 Msm3 (2140 Mbbl) recoverable oil equivalents have been discovered. For the middle Jurassic Play, the yet-to-find potential may be around 50 Msm3, distributed in several small structures in the basin. Following the oil discovery in the Middle Triassic interval in the Goliat structure, and because several of the previously drilled structures only penetrated the Jurassic and the uppermost Triassic section, considerable exploration potential may exist in the deeper Triassic interval in structures with the best reservoir facies. Stratigraphic traps of Cretaceous age may have a moderate petroleum potential, with excellent reservoirs encountered along the flank of the basin. Exploration potential may also exist in Upper Permian sandstones along the southern and eastern flanks of the basin. However, in large parts of the basin, the remaining potential is in the deep structures and hence is gas prone.


2021 ◽  
Vol 251 ◽  
pp. 698-711
Author(s):  
Grigorii Cherdantsev ◽  
Aleksander Zharkov

The article discusses the prospects for the oil and gas content of the Upper Permian deposits in the southwestern marginal part of the Vilyui syneclise. In this margin, the Permian terrigenous complex with proven oil and gas productivity in the central part of the syneclise, pinches out. The study area, represented by the monoclinal slopes of the Vilyui syneclise, is considered a promising area for the exploration of non-structural hydrocarbon traps in the Upper Paleozoic sediments. The objectives of the study include identifying general patterns of sediment formation, associated mainly with the development of the alluvial complex, and substantiating the potential opportunities of migration and accumulation of hydrocarbons in the predicted traps. The research is based on the interpretation of the latest seismic surveys and prior-years geological and geophysical data. Authors carried out structural and paleo-structural analysis, identified lithofacies in the well log, generalized and analyzed the geochemical conditions of the oil and gas content of the Upper Permian deposits, traced the pinching out of the Upper Permian deposits on the southwestern margin of the syneclise, and also outlined areas of river valleys development that form zones of advanced reservoirs. The results of the studies have validated promising oil and gas accumulation zones on the southwestern slopes of the syneclise associated with non-anticlinal hydrocarbon traps. Authors also drew up a diagram of the oil and gas potential of the Upper Permian deposits. The obtained results are of interest for prospecting for oil and gas in the area under study.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3102
Author(s):  
Anna Chmielowska ◽  
Anna Sowiżdżał ◽  
Barbara Tomaszewska

There are many oil and gas fields around the world where the vast number of wells have been abandoned or suspended, mainly due to the depletion of reserves. Those abandoned oil and gas wells (AOGWs) are often located in areas with a prospective geothermal potential and might be retrofitted to a geothermal system without high-cost drilling. In Poland, there are thousands of wells, either operating, abandoned or negative, that might be used for different geothermal applications. Thus, the aim of this paper is not only to review geothermal and petroleum facts about the Eastern Carpathian Foredeep, but also to find out the areas, geological structures or just AOGWs, which are the most prospective in case of geothermal utilization. Due to the inseparability of geological settings with both oil and gas, as well as geothermal conditionings, firstly, the geological background of the analyzed region was performed, considering mainly the autochthonous Miocene formation. Then, geothermal and petroleum detailed characteristics were made. In the case of geothermal parameters, such as formation’s thickness, temperatures, water-bearing horizons, wells’ capacities, mineralization and others were extensively examined. Considering oil and gas settings, insights into reservoir rocks, hydrocarbon traps and migration paths issues were created. Then, for evaluating geothermal parameters for specific hydrocarbon reservoirs, their depths were established based on publicly available wells data. Thereafter, the average temperatures for selected reservoirs were set. As the effect, it turned out that most of the deposits have average temperatures of 40/50 °C, nonetheless, there are a few characterized by higher (even around 80 °C) temperatures at reasonable depths.


The Geologist ◽  
1858 ◽  
Vol 1 (4) ◽  
pp. 124-129
Author(s):  
George Phillips Bevan

In my former paper I endeavoured to describe the general appearance and characteristics of the limestone, millstone grit, and Pennant rocks of this coal-field, and shall now proceed to give a brief outline of the coal measures themselves and their fossil contents. As I stated before, the character of the coal is materially different in different parts of the basin; for instance, if a line be drawn from Merthyr to the sea in a south-western direction, it will divide the basin into two unequal portions, the eastern one containing bituminous coal, and the western the anthracite. I do not mean to say that there is an exact line of demarcation between the two kinds of coal, but merely that such a boundary will seem to show pretty well where the two qualities pass into one another. Curiously enough, too, in the western or anthracite portion the seams are anthracitic in the northern bassets, while the southern outcrops of the same veins are bituminous. The anthracite is now in very great demand; but, formerly, people would have nothing to do with it, and there was even a law passed to prevent its being burned in London, on account of its supposed noxious qualities, and the idea that it was detrimental to health. It differs from the bituminous coal principally in containing more carbon, less bituminous matter, and less ashes; and, as a consequence, is a much cleaner-burning coal. We may, however, dismiss the anthracite, as this portion of the field is destitute of it.


Author(s):  
С.К. Курбаниязов

В начале барремского времени море отступило и до начала позднего альба территория представляла собой низменную аккумулятивную равнину, в пределах которой происходило накопление аллювиальных и озерно-аллювиальных отложений: красно-коричневых глин, алевролитов с прослоями коричневых песчаников и песков и линзами темно-серого лигнита. В основании толщи отмечаются гравелиты и конгломераты. В раннемальбе произошла кратковременная трансгрессия моря, однако территория современного Восточного Приаралья не была затоплена и представляла собой прибрежно-морскую равнину, где накапливались глины, алевролиты и песчаники. К концу позднего альба море регрессировало, и территория вновь стала представлять собой низменную аллювиально-озерную равнину. По всей территории происходило накопление пестроцветных глин, зеленовато-серых алевролитов, песков и песчаников, а также углей. При проведении иследовательских работ были обоснованы наиболее перспективные типы ловушек углеводородного сырья по стратиграфическим уровням и выявлена зональность их распространения. Дана оценка перспектив района на выявление залежей нефти и газа. Выделены информативные и качественные признаки (критерии) нефтегазоносности. Обоснованы площади и конкретные структуры для постановки детальных поисковых работ на выявление залежей нефти и газа. Рассчитана оценка потенциальных ресурсов углеводородного сырья. At the beginning of the Barremian time, the sea receded and until the beginning of the late Alb, the territory was a low-lying accumulative plain, within which the accumulation of alluvial and lacustrine-alluvial deposits occurred: red-brown clays, siltstones with layers of brown sandstones and sands and lenses of dark gray lignite. Gravelites and conglomerates are noted at the base of the strata.In the Rannemalba, there was a short-term transgression of the sea, but the territory of the modern Eastern Aral Sea region was not flooded and was a coastal-sea plain, where clays, siltstones and sandstones accumulated. By the end of the Late Alb, the sea regressed and the area again became a low-lying alluvial-lacustrine plain. There was an accumulation of variegated clays, greenish-gray siltstones, sands and sandstones, as well as coals throughout the territory. During the research work, the most promising types of hydrocarbon traps were justified by stratigraphic levels and the zoning of their distribution was revealed. The assessment of the prospects of the area for the identification of oil and gas deposits is given. Informative and qualitative signs (criteria) of oil and gas potential are identified. The areas and specific structures for setting up detailed search operations to identify oil and gas deposits are justified. The estimation of potential resources of hydrocarbon raw materials is calculated.


2021 ◽  
pp. 148-168
Author(s):  
Yaroslav G. Gribik

The results of geological exploration for oil within the Elsky, Shatilkovsky, Savichsky and Petrikovsko-Shestovichsky sections of the Pripyat trough are analyzed. The analysis covers almost 70 years from the drilling of the first exploratory wells laid by the "wild cat" method to the modern comprehensive justification. During the analyzed period, from 12 to 23 deep wells were drilled with a total penetration of 42.3 thousand meters to 68.3 thousand meters in each section. The initial stage of work after the first oil inflow is characterized by a higher activity of drilling new exploratory wells, justified by the methods available at that time. The negative result of exploratory drilling in certain areas is also due to the significant fragmentation of the intrasalt perspective horizons and the areal unevenness of reservoir layers in the subsalt complex. Within the boundaries of the sites, deposits with recoverable oil reserves of no more than 450 thousand tons are established, which can be determined as a low economic efficiency of prospecting operations. However, the work has played a positive role in determining real models of hydrocarbon traps for use in the study of other sites.


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