Sedymentacja i paleogeografia dolomitu głównego a jego ropo- i gazonośność
Abstract
SEDIMENTATION AND PALEOGEOGRAPHY OF THE MAIN DOLOMITE AND ITS OIL- AND GAS-BEARING
Summary
Zechstein Main Dolomite belong to the most perspective oil- and gas-bearing horizons in the platform areas of the Polish Lowlands. Up to the present, 13 deposits of natural gas and 7 deposits of oil were discovered and there is a real possibility of further discoveries in this horizon. The sedimentological and paleogeographic studies are here of a special importance as the make it possible to differentiate lagoonal, barrier, for-barrier and shallow and deep shelf plain zones and, therefore, to select trends in the search. The lithological characteristics and development of these zones in different parts of the basin are discussed.
Onkolite and oolite rocks are main collector rocks. They are common in barrier zone, some parts of the lagoon zone and, sometimes, fore-barrier and shallow shelf plain zones. Oil and gas deposits occur in barrier and, sometimes, lagoonal and, occasionally, fore-barrier zone. Single deposits may be also expected in shallower parts of the shelf plain. The analysis showed that the deposits are related to local elevations and zones of tectonic disturbances and are of the lithological-structural type. The main perspectives of discovery of new deposits are connected with searching along the Lubuska and Silesian barriers and western parts of the Pomeranian barriers. The Góry Świętokrzyskie barrier, shallower part of shelf east of the Lubuska barrier and western part of the Old Platform should be treated as important subject of further studies. The perspectives of discovery of hydrocarbon accumulations in the remaining parts of the barriers are low if ever, mainly because of groundwater exchange proceeding freely in these areas.
Summary
Zechstein Main Dolomite belong to the most perspective oil- and gas-bearing horizons in the platform areas of the Polish Lowlands. Up to the present, 13 deposits of natural gas and 7 deposits of oil were discovered and there is a real possibility of further discoveries in this horizon. The sedimentological and paleogeographic studies are here of a special importance as the make it possible to differentiate lagoonal, barrier, for-barrier and shallow and deep shelf plain zones and, therefore, to select trends in the search. The lithological characteristics and development of these zones in different parts of the basin are discussed.
Onkolite and oolite rocks are main collector rocks. They are common in barrier zone, some parts of the lagoon zone and, sometimes, fore-barrier and shallow shelf plain zones. Oil and gas deposits occur in barrier and, sometimes, lagoonal and, occasionally, fore-barrier zone. Single deposits may be also expected in shallower parts of the shelf plain. The analysis showed that the deposits are related to local elevations and zones of tectonic disturbances and are of the lithological-structural type. The main perspectives of discovery of new deposits are connected with searching along the Lubuska and Silesian barriers and western parts of the Pomeranian barriers. The Góry Świętokrzyskie barrier, shallower part of shelf east of the Lubuska barrier and western part of the Old Platform should be treated as important subject of further studies. The perspectives of discovery of hydrocarbon accumulations in the remaining parts of the barriers are low if ever, mainly because of groundwater exchange proceeding freely in these areas.