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Slowakiewicz M.,Polish Geological Institute | Mikolajewski Z.,Polish Oil and Gas Company
Marine and Petroleum Geology | Year: 2011

Various microbialite lithofacies were common in the shallow-water environments which flourished under highly saline and arid climate conditions in the Polish part of the Zechstein (Upper Permian) Main Dolomite (Ca2) carbonates. Data came from detailed analysis of 78 cores from wells located at the southern and northern margins of the Main Dolomite basin in west Poland. Microbialite lithofacies are represented by columnar, planar and domal stromatolites, clotted thrombolites and biolaminites developed in high-to-low energy environments within the upper slope, lower parts of oolitic barrier/shoal, restricted lagoon, and tidal flat and tidal channel zones. In barrier environments ooids were predominant whereas in lagoonal settings microbial oncoids and peloids were common. In basinal settings laminated dolomudstones formed which are regarded as hemipelagic and are partly pelagic microbial in origin. Microbial communities coexisted with algae and developed mainly within shallow marine environments. Microbialites are built of cyanobacterial filaments and organo-mineral coccoidal forms possibly of bacterial origin. Organic geochemistry data confirm that organic matter was transformed by cyanobacteria and bacteria which may have played a main role in hydrocarbon generation. This is confirmed by C29 to C35 hopanes, Pr/Ph ratio below 1.0, and the presence of gammacerane as typical for Ca2 profiles. The role and occurrence of algae, as confirmed by C29-steranes, in hydrocarbon generation was possibly minor. Thus it is concluded that the Main Dolomite microbialites could be the likely source rocks for hydrocarbons, with calculated original TOC values from 0.8 to ca 2.0 wt. %. These units also form the reservoir rocks, with porosities reaching 20%. © 2011 Elsevier Ltd.

Peryt D.,Polish Academy of Sciences | Peryt T.M.,Polish Geological Institute National Research Institute | Raczynski P.,Wroclaw University | Chlodek K.,Polish Oil and Gas Company
Geological Quarterly | Year: 2012

The basal Zechstein succession in SW Poland is dominated by breccias and/or conglomerates or extraclast-bearing bioclastic limestones, which were deposited during rapid flooding of the pre-existing intracontinental basin in the early Lopingian (Late Permian). Of these, the boulder-cobble breccias and conglomerates are interpreted as deposited in a rocky shore-zone where density flows and upwelling pre- vailed. The breccias gradually pass up into bryozoan (or other bioclastics) grainstones. The matrix-supported breccias were deposited as large extraclasts and blocks of Carboniferous rock were rolled down or detached from a cliff and were then either embedded into a carbonate sand or formed a framework supplying voids that could be colonized by tubular encrusting foraminifers. These foraminifers abound in all basal Zechstein facies (except in the debris-flow deposits) and are attributed to Palaeonubecularia. The associated faunas include other foraminifers (uniserial and hemigordiopsids), bryozoans, brachiopods, bivalves, gastropods, and microbial deposits. The prolific growth of tubular encrusting foraminifers has resulted from nutrient supply from the basin by upwelling. Botryoidal aragonite cements (also interpreted as due to upwelling) also characterize the basal Zechstein strata, although they were previously reported only from the upper Zechstein Limestone. The δ I3C values of the basal Zechstein deposits show small variation and oscillated around 4.0%o, suggesting that these deposits are younger than the Kupferschiefer.

Peryt T.M.,Polish Geological stitute National Research stitute | Raczynski P.,Wroclaw University | Peryt D.,Polish Academy of Sciences | Chlodek K.,Polish Oil and Gas Company
Geological Journal | Year: 2012

Stromatolite and bryozoan build-ups from the Werra Cycle (Zechste) of the Southern Permian Bas of Europe meet all defitions given by various authors for reefs and they commonly occur at the shelf edge. a few places, cludg western Poland, they are also recorded the basal facies. The ma part of the reef is formed by fragmented bryozoan zoaria. The reef biota are a typical bryonoderm association dicatg cool-water and cold-water environments. A characteristic feature is a large amount of fragmented skeletal remas lackg rigidity. The ma part of the reefs is built of rudstones, and only stromatolitic crusts form massive constructions. Remarkable is the mechanism of the orig of clearly morphologically separated reef constructions from the remas of a relatively low potential of fossilization. Zones built of crushed remas domate over parts representg massive constructions. The colonization of the substrate began very early, as dicated by the terbeddg of breccia and bioclastic carbonates the lowermost part of the Zechste Limestone some reef sections. The Zechste Limestone reefs of western Poland abound the hemispheroid (botryoid) aragonitic cement that is otherwise common for the Zechste reefs. The abundance of the cement recorded Permian reefs is terpreted as the result of an unusually high saturation state of surface seawater because of a number of factors, cludg prolific carbonate precipitation due to the occasional upwellg of warmer sale waters on shelf environments the stratified Zechste Bas. The pervasive carbonate precipitation the reef area contrasts with a restricted carbonate precipitation the adjog bas where very th sequences have accumulated. © 2012 John Wiley & Sons, Ltd.

Kosakowski P.,AGH University of Science and Technology | Lesniak G.,Institute of Oil and Gas | Krawiec J.,Polish Oil and Gas Company
Annales Societatis Geologorum Poloniae | Year: 2012

During the 50-year-long intense petroleum exploration of the Palaeozoic-Mesozoic basement of the Carpathian Foredeep, more than 20 oil and gas accumulations have been discovered. The basic and most important oil-bearing levels in the Mesozoic section are Oxfordian carbonates and Cenomanian sandstones. The Nosówka, Zalesie, Trzebownisko-Krasne, Cetynia, Uszkowce and Lachowice hydrocarbon accumulations and numerous hydrocarbon shows have been found in the Palaeozoic horizons. This paper is focused on evaluation of reservoir properties of the entire Palaeozoic-Mesozoic basement of the Carpathian Foredeep and marginal part of the Outer Carpathians for finding new reservoir horizons. 558 rock samples from 51 wells in the Kraków-Lubaczów area were analysed. The well log results from 20 wells were additionally used for the assessment of petrophysical properties. The results of porosimetry measurements and well logs varied in all discussed Palaeozoic and Mesozoic basement horizons of the Carpathian Foredeep. The best reservoir properties were estimated within the Jurassic-Lower Cretaceous carbonate complex. Despite great variability, the carbonate rocks display highest average porosity and good permeability values. The variability of reservoir properties is mostly a result of the character of the reservoir-porous-fracture space. Good reservoir properties were also estimated for the Upper Cretaceous carbonate rocks. However, in most of the analysed wells the potential reservoirs were watered. The Palaeozoic complex displays weaker reservoir properties and they mainly refer only to the Devonian-Lower Carboniferous horizon. The Lower Palaeozoic rocks display weak reservoir properties. Their potential is additionally lowered by negligible range of occurrence and a small thickness. Generally, the gas- and oil-bearing properties of the analysed zone can be attributed only to the Jurassic-Cretaceous reservoir horizons. The remaining horizons, especially the Upper Palaeozoic complex, are only supplement to the reservoir potential of the area.

Kudrewicz R.,Polish Oil and Gas Company
Geoinformatics 2010 - 9th International Conference on Geoinformatics: Theoretical and Applied Aspects | Year: 2010

PGNiG is the Polish national petroleum company. The company's cartographic database has been under construction for over 12 years. It started with a collection of paper maps and one license of UNIX-based ARC/INFO. Now the cartographic database located on LAN-type network is used by over 50 active users in 6 offices. Recent developments include the collection and storage of 100k topo base maps (on-line), 50k raster and vector base maps (off-line), administrative vector data, field data, 2D and 3D seismic location data, environmental data and many others. The database is interactively connected to the well database. As result of changing the hardware-software environment the data formats and storage mode were also changed from dispersed database based on the shape-files and TIFFs into a more integrated form of a database based on the FileGeodatabase format. Parallel to the increase of information, construction and numeric format changes the distribution of data sources changed. At the beginning most of the data was produced within the company. Now an important amount of data is purchased or acquired from public sources. Future plans ⋯ the construction of a professional cartographic data server based on ESRI server solutions.

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