Can stratigraphic plays change the petroleum exploration outlook of the Netherlands?

Abstract

AbstractFifty years after the discovery of the giant Groningen gas field, good insight into the remaining hydrocarbon exploration potential of the Netherlands is of great interest due to the aging infrastructure. In a review of prospective areas, the stratigraphic element of Dutch play areas has been summarized for conventional and unconventional formations. This is to answer the question of whether stratigraphic traps can contribute to future exploration. Complex faulting, very common in the Dutch subsurface, makes structural definition generally the highest prospect risk. With increase in 3D coverage over the country, many structures have now been drilled successfully. The success of structural traps has left the stratigraphic plays and prospects under-explored. Most hydrocarbon reserves in the Netherlands have been discovered in Permian Rotliegend and Triassic Bunter sandstone reservoirs, which are not prone to much stratigraphic trapping as a consequence of very gradual facies changes. Other prospective horizons and hydrocarbon reservoirs in the country range in age from Carboniferous to Cenozoic and can be found in clastic and carbonate rocks. They share an overall comparable basin setting but the varying interplay at basin margins creates varying stratigraphic elements. Rifting creates new facies variation during the Mesozoic. Salt movement is another factor that creates stratigraphic components in trapping. The various erosional events create other possibilities for stratigraphic trapping. This, combined with varying relative sea-levels through time, creates very distinct stratigraphic intervals often correlatable over large distances. The very limited contribution of stratigraphic traps to present-day gas finds may change in the future because of improved seismic. Risking of prospects needs better understanding of stratigraphic elements in various plays. This includes the stratigraphic aspects of reservoir sealing in dominantly structural traps and the nature of source horizons.