Wyniki wyszukiwania - Biblioteka Nauki

1

Predicting porosity through simulating quartz cementation of Middle Cambrian sandstones, West Lithuania

100%

Šliaupa S.

Geological Quarterly

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2006

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tom Vol. 50, No. 2

247-256

EN

Quartz cementation is a major parameter controlling the reservoir properties of the Middle Cambrian quartz arenites of the central and western parts of the Baltic Basin. Marked local variations in the porosity and permeability severely complicate oil exploration and exploitation inWest Lithuania. Commonly, the porosity of the oil reservoirs is 6–8%. Therefore even minor changes in the porosity have a considerable impact on the potential of oil fields. A predictive model of the quartz cementation is proposed, based on kinetic modelling results. The precipitation rate-limiting model effectively explains sharp variations in quartz cementation controlled by grain-size changes. The model was further improved by incorporating the sorting factor. Even so, the amount of quartz cementation is overpredicted by 4–7% in some intervals, implying that the precipitation rate-limiting model is too simplified. A good correlation was obtained between stylolite spacing and quartz cementation, the overpredicted quartz amount increasing with an increase in stylolite spacing. The modelling results argue against any discernable impact of the oil on the reservoir quality of the sandstones. The successful prediction of reservoir quality mainly depends on correct reconstruction of the sedimentary environment of the Middle Cambrian deposits. The evolutionary model of the quartz cementation suggests a good reservoir quality of the Cambrian sandstones during the later part of Late Palaeozoic, when most of oil was generated in the basin.

2

Neogene - quaternary tectonic history of the Baltic Syneclise

63%

Šliaupa A. , Šliaupa S.

Technika Poszukiwań Geologicznych

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1999

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tom R. 38, nr 1

102-105

EN

The Baltic Syneclise (BS) was established in the Early Cambrian as part of the Dniestr-Baltic system of pericratonic basins. Since then, it has subsided more than 3 km. However, the shape of the BS has been far from stable during its history. Since the Permian, the axis of greatest subsidence has gradually migrated southwards, such that Neogene sediments are either absent from the syncline or are very restricted. Thus, at least during the earlier part of the Neotectonic stage, the southern part of the BS was low-lying and the northern, elevated. The Neotectonic stage is represented only by relatively thick (>200 m) glaciogenic sediments of continental type. The total amplitudes of the Neotectonic vertical movements were calculated from the approximated altitudes of the sub-Quaternary Surface (SQS). The map of total Neotectonic amplitudes shows obvious modifications to the pattern of Neogene tectonic disturbance. Westwards-increasing susbsidence is in sharp contrast to the southwards trend during the Neogene. It is perhaps surprising that the shape of the BS, as defined by the SQS, is quite close to that of Palaeozoic times, whereas its evolution during the Neogene was essentially a continuation of Alpine events. Hence, it is obvious that a drastic change in the overall pattern of structural development took place in the middle of the Neotectonic stage.

PL

Założenia syneklizy bałtyckiej (BS) powstały we wczesnym kambrze, jako część dniestrzańsko-bałtyckiego systemu basenów perykratonicznych. Od tego czasu subsydencja przekroczyła 3 km. Jednakże kształt syneklizy bałtyckiej zmieniał się w tym czasie. Od permu linia największej subsydencji przemieszczała się stopniowo ku południowi, tak dalece, że osady neogenu zachowały się tylko w szczątkowym stanie. Z tego wynika, że już na początku etapu aktywności neotektonicznej południowa część syneklizy bałtyckiej była obniżona, podczas gdy północna była podniesiona. Osady z etapu aktywności neotektonicznej są reprezentowane jedynie przez czwartorzędowe utwory lodowcowe typu kontynentalnego o znacznej (>200 m) miąższości. Łączne amplitudy pionowych ruchów neotektonicznych były obliczane w nawiązaniu do przybliżonej wysokości powierzchni utworów przedczwartorzędowych (SQS). Z mapy łącznych amplitud ruchów neotektonicznych wynika oczywista modyfikacja trendów subsydencji w Neogenie na zachodnie, w stosunku do wcześniejszych południowych. Pewne zaskoczenie stanowi zachowanie na mapie hipsometrycznej powierzchni utworów przedczwartorzędowych kształtu syneklizy bałtyckiej z ery paleozoicznej. Natomiast ewolucja neogeńska syneklizy stanowiła kontynuację zjawisk tektonicznych alpejskich. Tak więc staje się oczywiste, że drastyczne zmiany trendów rozwoju tektonicznego syneklizy odbyły się dopiero podczas zaawansowanych zjawisk neotektonicznych.

3

Morphotectonic implication of the Paleoproterozoic Mid-Lithuanian Suture Zone

51%

Šliaupa S. , Satkūnas J. , Motuza G. , Šliaupienė R.

Geological Quarterly

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2017

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tom Vol. 61, No. 3

590--601

EN

The Paleoproterozoic Mid-Lithuanian Suture Zone represents one of the major structures of the crystalline basement of Lithuania, separati ng the West Lithuanian and the East Lithuanian domains. This zone has shown persistently low tectonic activity during the Phanerozoic. The Mid-Lithuanian Suture Zone is marked by a distinct Middle Lithuanian topographic low underlain by a trough in the sub-Quaternary surface that suggests the morphotectonic nature of this depression. This is supported by high-precision geodetic level l ing data that has unravelled the subsidence trend of the Middle Lithuanian trough. The zone is also distinct in its pattern of topographic lineaments. The persistence of the tectonic activity of the Mid-Lithuanian Suture Zone suggests that it represents a large-scale mechanical boundary of the Earth's crust, resulting in increased accumulation of tectonic strain.

4

Lithology and diagenesis of the poorly consolidated Cambrian siliciclastic sediments in the northern Baltic Sedimentary Basin

38%

Raidla V. , Kirsimäe K. , Bityukova L. , Joeleht A. , Shogenova A. , Šliaupa S.

Geological Quarterly

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2006

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tom Vol. 50, No. 4

395-406

EN

The present study discusses lithology and diagenetic characteristics of the siliciclastic Cambrian and the enclosing Ediacaran and Ordovician deposits in the northern Baltic Sedimentary Basin (BSB). The Neoproterozoic and Lower Palaeozoic sediments are despite their age unconsolidated with primary porosity of 20-25% for both shales and sandstones. The sparse Fe-dolomite cementation of arenitic and subarenitic sandstones and siltstones occurs mainly at lithological contacts with the massive Ediacaran and Lower Cambrian claystones and is probably related to ions released during llitization. In contrast to weak mechanical and chemical compaction of sandstone, the clay mineral diagenesis of Cambrian deposits is well advanced. The highly illitic (80-90%) nature of illite-smectite (I-S) suggests evolved diagenetic grade of sediments which conflicts with shallow maximum burial and low compaction. Smectite-to-illite transformation has resulted in formation of diagenetic Fe-rich chlorite in claystones. Some porosity reduction of sandstones is due to formation of authigenic kaolinite at the expense of detrital mica or K-feldspar.

5

CO2 storage potential of sedimentary basins of Slovakia, the Czech Republic, Poland and the Baltic States

23%

Šliaupa S. , Lojka R. , Tasáryová Z. , Kolejka V. , Hladík V. , Kotulová J. , Kucharič L. , Fejdi V. , Wójcicki V. , Tarkowski R. , Uliasz-Misiak B. , Šliaupienė R. , Nulle I. , Pomeranceva R. , Ivanova O. , Shogenova A. , Shogenov K.

Geological Quarterly

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2013

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tom Vol. 57, No. 2

219–-232

EN

It has been increasingly realised that geological storage of CO2 is a prospective option for reduction of CO2 emissions. The CO2 geological storage potential of sedimentary basins with the territory of Slovakia, the Czech Republic, Poland, and the Baltic States is here assessed, and different storage options have been considered. The most prospective technology is hydrodynamic trapping in the deep saline aquifers. The utilisation of hydrocarbon (HC) fields is considered as a mature technology; however storage capacities are limited in the region and are mainly related to enhanced oil (gas) recovery. Prospective reservoirs and traps have been identified in the Danube, Vienna and East Slovakian Neogene basins, the Neogene Carpathian Foredeep, the Bohemian and Fore-Sudetic Upper Paleozoic basins, the Mesozoic Mid-Polish Basin and the pericratonic Paleozoic Baltic Basin. The total storage capacity of the sedimentary basins is estimated to be as much as 10170 Mt of CO2 in deep saline aquifer structures, and 938 Mt CO2 in the depleted HC fields. The utilisation of coal seams for CO2 storage is related to the Upper Silesian Basin where CO2 storage could be combined with enhanced recovery of coal-bed methane.