Probing the Limits of the Economic Basement in Northwest Europe

Van Hulten, Fred F.N., Energie Beheer Nederland, Heerlen, Netherlands

After the giant Groningen gas discovery in 1963, exploration in the Netherlands and the Dutch Southern North Sea has mainly been been focused on the Carboniferous (Pennsylvanian i. e. Westphalian) petroleum system. This led to the discovery of over 250 gas fields, charged mainly from Westphalian coal layers, in formations ranging from Carboniferous to Cretaceous age. Exploration in this mature area, based on the convention­al plays, is still successful. However new attractive prospects will be more and more diffi­cult to find and consequently radical different play concepts have to be investigated before the present infrastructure is abandoned. This leads to an old question, whether hidden underneath the thick Westphalian and Namurian section, that almost covers the entire Netherlands, an undiscovered petroleum system is present in Mississippian (Dinantian) car­bonates. Discoveries in the Caspian Sea, have reignited a play concept that assumes a Dinantian carbonate progradational wedge derived from the major highs in the southern Netherlands and Belgium. From the geological information of the surrounding countries and sparse well control, it is certain that thick Dinantian sections can be present. Canadian exam­ples, especially in the Dinantian Pekisko are helpful to formulate a number of trapping mech­anisms. Based on the subcrop patterns of the Westphalian, a preliminary paleogeography can be drawn as general outline for future exploration targets. Newer seismic can be used to see structures and details of this carbonate section that were not detected before.