Perspektywy występowania węglowodorów naftowych w Polsce

Abstract

PROSPECTS FOR HYDROCARBON OCCURRENCE IN POLAND Summary The present paper reviews certain problems on the prospects for oil and gas exploration in Poland. An attempt has been made to present the most prospective areas within the Cambrian through Tertiary deposits (figs. 1-7) based on the evolution of the Middle-Polish and Carpathian depositional basins as well as on the information on hydrocarbon migration from the central towards the more elevated parts of the basin and also towards the minor elevations appearing within the basin. The regions have been distinguished on the basis of the following criteria: the occurrence of the reservoir rocks within the clayey or another sealling off complex, hydrocarbon shows, the character of the subsurface -waters as well as the tectonic and palaeothermodynamic evolution of the depositional basin. A frequent remodelling caused by tectonic disturbances but mainly by depositional gaps and denudation usually affects unfavourably the behaviour of the accumulated hydrocarbons. The Mesozoic deposits of the Middle-Polish and the Tertiary of the Alpine (Carpathian) basin show more favourable conditions for hydrocarbon occurrence. So far the biggest oil and gas shows and deposits within the Palaeozoic have been found in the areas surrounding the Middle-Polish basin: in the fore-Sudeten monocline region (within Permian deposits), in the Lublin synclinorium (Devonian and Carboniferous), in the Peribaltic syneclize (Cambrian, Ordovician and Silurian). In spite of considerable tectonic disturbances these areas are worthy of further thorough explorations. The Mesozoic deposits are fairly prospective due to their minor tectonic disturbances, their shallower occurrence, good storage properties and the fact, that they are sealed off from the surface. Considering the criteria mentioned above zones of increased hydrocarbon accumulation possibilities have been distinguished within the individual units (figs. 4-7).