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Abstract The paper considers the problematics of identifying proper analogues for understanding carbonate and clastic reservoir distribution and prediction in the Lower Permian and Upper and Lower Carboniferous within the Dnieper-Donets basin. The focus of the exploration team was finding meandering rivers. This choice was proven good in mapping reservoirs and finding traps deeper in the Upper and Middle Carboniferous, although for Permian clastic section the approach was not helpful. The second option was desert dunes, but poor sorting of reservoirs suggests a more complex picture. Analogues such as desert environment is quite logical for describing Lower Permian as aridic climate, with red and brown shales and sands. Lower Permian reservoirs have a moon-like shape in the vertical sections that could be easily mistaken for river channels, but in such a dry climate, it is very likely water flow channels with sporadic hurricane-related activities. Core and logs shows chaotic grain sizes, but more with fine grains with almost no coarse grains. The source of sedimentary material could be mountains of Ukrainian Rock Shield from the South and Voronezh massif from the North. This conceptual model is proposing not to look for meandering channels, but more for braided channels with poorly sorted material. The current time analogue could be the Oman desert between the mountains and peninsula. From satellite images, braided channels are clearly visible in the direction towards the Indian Ocean. The channels’ internal structure is quite heterogeneous. This method suggests exploration targets with possible widths of the channels as big as hundreds of meters and their lengths under 10 and between 10-20 kilometres maximum.
Abstract Context is everything. Not all thick sands pay out and not all thin sands are poorly productive. It is important to understand a basin's palaeogeographical drivers, the resultant palaeoenvironments and their constituent sedimentary architecture. Development of a depositional model can be predictive with respect to the magnitude of accessible pore space for potential development. We present a multi-field study of the Dneipr-Donets basin. Over 600 wells were studied with >4500 lithostratigraphical picks being made. Over 7500 sedimentological picks were made allowing mapping of facies bodies and charting shifts in facies types. A facies classification scheme was developed and applied. The Devonian-Permian sedimentary section records the creation, fill, and terminal closure of the Dneipr-Donets Basin:Syn-rift brittle extension (late Frasnian-Famennian): intracratonic rifting between the Ukrainian Shield and Voronezh Massif formed a NW-SE orientated trough, with associated basaltic extrusion. Basin architecture consists of rotated fault blocks forming graben mini-basins. Sedimentation is dominantly upper shoreface but sand packages are poorly correlatable due to the faulted palaeotopography. Early Post-rift thermal subsidence (Visean-Lower Bashkirian): the faulted palaeotopography was filled and thermal subsidence drove basin deepening. Cyclical successions of offshore, lower shoreface and upper shoreface dominate. Sands are typically thin (<10m) but can be widely correlated and have high pore space connectivity. Mid Post-rift: the Bashkirian (C22/C23 boundary), paralic systems prograde over the shoreface. Changes in vertical facies are abrupt due to a low gradient to basin floor. Deltaic and fluvial facies can produce thick amalgamated sands (>30m), but access limited pore space because they are laterally restricted bodies. Terminal post-rift (Mykytivskan): above the lower Permian, the convergence of the Kazahkstanian and Siberian continents began to restrict the Dnieper-Donets basin's access to open ocean. The basin approached full conditions and deposition was dominated by evaporite precipitation, with periodic oceanic recharge. Ultimately, this sediment records the formation of Pangea. The successions examined were used to construct a basinal relative sea level curve, which can be applied elsewhere in the basin. This can be used to help provide palaeogeographical context to a field, which in turn controls the sedimentary architecture.
Subbotin, S. I. (Institute of Geophysics of the Ukrainian Academy of Sciences) | Sollogub, V. B. (Institute of Geophysics of the Ukrainian Academy of Sciences) | Lossovsky, E. K. (Institute of Geophysics of the Ukrainian Academy of Sciences) | Chekunov, A. V. (Institute of Geophysics of the Ukrainian Academy of Sciences) | Chirvinskaya, M. V. (Geophysical Trusts of the Ministry of Geology of Ukrainian S.S.R., U.S.S.R.) | Garkalenko, I. A. (Geophysical Trusts of the Ministry of Geology of Ukrainian S.S.R., U.S.S.R.) | Turchinenko, P. T. (Geophysical Trusts of the Ministry of Geology of Ukrainian S.S.R., U.S.S.R.)
Abstract The structure of the oil- and gas-bearing regions of the Ukraine-the Dnepro-Donetsk and Black Sea depressions-has been investigated by means of seismic techniques. A cross-section of the earth's crust has been constructed along the profile the Black Sea-Voronezh Massif. The prospective oil structures are revealed in the sedimentary complex, the hypsometry of the basement is studied and the data concerning the topography of the Conrad and Mohorovicic discontinuities obtained. Numerous deep fractures have been revealed responsible for the block structure of the earth's crust. Uplifts of the earth's crust in the Ukranian and the Voronezh Massifs are caused by the expansion of the mantle substance and its subsidence in the Black Sea and Dnepro-Donetsk depressions is connected with the contraction of the mantle substance. The reverse topography of the Mohorovicic discontinuity as regards the upper crustal strata configurations is connected with its phase transition basalt 2 eclogite. Study of the sedimentary cover and increasing the depth of investigation by seismic methods become complicated because of the presence of multiple reflections. Their identification has been carried out by means of:Conventional methods, using the difference between kinematic characteristics of primaries and multiples; "The plain front" method, using the possibility of regulation of the depth of "the plain front" formation; The modelling of wave propagation process in a multilayer medium on digital computers (synthesizing of theoretical seismograms). by S. I. SUBBOTIN, V. B. SOLLOGUB, E. K. LOSSOVSKY, A. V. CHEKUNOV Institute of Geophysics of the Ukranian Academy of Sciences and M. V. CHIRVINSKAYA, I. A. GARKALENKO, P. T. TURCHINENKO Geophysical Trusts of the Ministry of Geology of Ukrainian SSR, USSR Résumé La structure des régions pétrolifères d'Ukraine-les dépressions Dneprovsko-Donetskaja et Pritchernomorskaja-a été étudiée par les méthodes sismiques. La section de la croûte terrestre a été construite pour le profil la Mer Noire-le Massif Veronezhskie. Dans un ensemble sédimentaire les structures perspectives ont été révelés, la hypsométrie d'une socle a été étudiée, la topographie des surfaces de Konrad et de MohoroviciC a été obtenue. Plusieurs fractures profondes causant la structure en bloc de la croûte terrestre ont été révelées. Les élévations de la croûte terrestre en régions de Massif d'Ukraine et de Massif Voronezhskie sont causées par la dilatation de la substance de Manteau; et la descente en régions de Depression Pritchernomorskaja et de Depression Dneprovsko-Donetskaja est associée avec la compression de la substance de Manteau. Un relief de la discontinuité de MohoroviciC, convertée par rapport à formes de milieu situé