The Rotliegend Basin is filled with terrigenic complex over 1200 m in thickness. The complex comprises sediments of eolian, fluvial and playa depositional systems (Fig. 1). Reservoir volume of the pore space accessible for the reservoir media is ca. 830-990 km3. Gas exploration in this stratigraphic unit is now focused at depths of around 3000-3800 m b.s.l., in the near-top zone. Poor reservoir properties, especially permeabilities, are here the limiting factor for conventional exploration. A change in the prospecting strategy to comprise tight gas targets moves research into the deeper zone covering the whole profile of the Rotliegend. The paper presents preliminary results of 3D modeling of lithofacies and related petrophysical parameters variability. The static model was created with the use of Petrel 2009.2. Structural framework was built using regional structural, isopach and facies maps. It was relatively detailed, comprising 9 576 000 cells organized in 3 zones and 60 layers. To estimate facies model, the authors used results of integrated environmental analysis of core data and logs from 117 wells (Fig. 2 ). Models of clay content (Vsh) and porosity (PHI) were based on logs from 75 wells. The obtained results show that the northern margin of the Eastern Erg is characterized by presence of numerous eolian strata with porosity ranging from 5 to 15%. Their quality, quantity and thickness decrease toward the north, along with increase in depth. Modeling results indicate that the dominating porous layers of eolian sandstones and fluvial inserts are often intercalated with "non-reservoir" layers revealing porosity below 5%. In this zone, a deeper part of the Rotliegend section should be investigated more thoroughly (Fig. 5, 6, 9). The Pomeranian sector of the Central Basin is dominated by playa and fluvial sediments (Fig. 7, 8, 10). Slightly clayey eolian strata make a few, laterally discontinuous intercalations. Gas accumulations could be expected within local, laterally confined interlayers of eolian and fluvial sandstones with porosity of around 5-12%. Due to the location in the near-base part of the Rotliegend section, close to Carboniferous source rocks, they may be filled with gas, forming so-called sweet spots. Probability of gas occurrence in Pomerania is high as indicated by the Międzyzdroje gas field or small accumulation found in Piaski-PIG2 well. The presented preliminary study allowed to test usability of 3D modeling in tight gas prospecting. Fully reliable results will be obtained after increasing precision of the models comprising detailed seismic interpretation, the use of seismic attributes, and inclusion of quantitative data in diagenetic processes and sedimentology of layers in the modeling process.
Numerical modelling of the Carboniferous–Permian petroleum system in the Polish Basin was carried out using PetroMod software. The Carboniferous source rocks contain organic matter mostly of a humic nature (gas-prone Type III kerogen). Subordinately, only in the Lower Carboniferous deposits, kerogen of algal marine origin and mixed Type II/III kerogen occur. The quantity of dispersed organic matter is variable, but usually below 2% TOC. In the Carboniferous section, a progressive increase in the maturity of organic matter with depth was observed, from approximately 0.5% Rr at the top of the Westphalian in marginal parts of the Carboniferous basin to over 5.0% Rr at the bottom of the Lower Carboniferous in the eastern Fore-Sudetic Homocline. The thermo- genic generation of hydrocarbons continued from the late Westphalian (eastern Fore-Sudetic Homocline and partly Pomerania) throughout the Mesozoic, up to the Late Cretaceous. The advancement of this process is va- riable in different parts of the Carboniferous basin, reaching up to 100% of kerogen transformation in the zones of maximum maturity of organic matter. However, the most intensive periods of gas generation and migration were the Late Triassic and the Late Jurassic. The most prospective areas are located NE of Poznań–Kalisz line and SW of Poznań.
The paper presents main energetic aspects of current geothermal district heating system in Poddębice, Poland, and its planned development in an optimal way from an energy and economic points of views (reservoir and production aspects are presented in Part 1). These topics, as part of pre-feasibility study, were elaborated in the framework of the EEA Project “Geothermal utilization potential in Poland – the town of Poddębice”. That town has both prospective resources and ambitious plans of further geothermal uses’ deployment for space heating and for wide range of other applications. They will contribute to low-emission heating, improvement the leaving conditions and modern local economy. Poddębice create a good study case for other localities in Poland which have geothermal resources. The paper gives in insight into the analyses, outcomes and recommendations that resulted from common works on Icelandic and Polish partners involved in the Project. Reservoir and production aspects are presented in Part 1 of this paper. The material presented in Part 2 is the result of the original work of the authors and includes only one citation of the literature. Most literary references were cited in part 1 accordingly.
PL
Artykuł przedstawia zagadnienia energetyczne dotyczące pracującego obecnie geotermalnego systemu ciepłowniczego w Poddębicach, jak i jego planowanego rozwoju z uwzględnieniem optymalnych sposobów funkcjonowania pod względem energetycznym i ekonomicznym (aspekty złożowe i eksploatacyjne są natomiast podane w części 1 artykułu). Tematy zostały opracowane jako część wstępnego studium możliwości w ramach Projektu EOG „Potencjał dla rozwoju wykorzystania energii geotermalnej w Polsce – miasto Poddębice”. Wymienione miasto posiada zarówno perspektywiczne zasoby, jak i znaczące plany rozwoju wykorzystania energii geotermalnej w ciepłownictwie i w szerokim zakresie innych zastosowań. Przyczynia się one do niskoemisyjnego ciepłownictwa, poprawy warunków życia oraz do nowoczesnej lokalnej działalności gospodarczej. Poddębice są dobrym przykładem dla innych miejscowości w Polsce, które posiadają zasoby geotermalne. Artykuł przedstawia wybrane analizy, ich wyniki oraz rekomendacje, które są rezultatem wspólnych prac zaangażowanych w Projekt partnerów z Islandii i Polski.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.