Modelling the hydrocarbon generation and migration in the West NetherlandsBasin, the Netherlands

The hydrocarbon systems of the Mesozoic, inverted West Netherlands Basin ha ve been analyzed using 2-D forward modelling. Three source rocks are consid ered in the modelling: Lower Jurassic oil-prone shales, Westphalian gas-pro ne coal deposits, and Lower Namurian oil-prone shales. The Lower Namurian h ydrocarbon system of the basin is discussed for the first time. According to the modelling results of the Early Jurassic oil system, the oi l accumulations were filled just after the main inversion event. Their pred icted locations are in agreement with exploration results. Modelling result s of the Westphalian gas system, however, show smaller and larger sized acc umulations at unexplored locations. The gas reservoirs were filled during t he Late Jurassic-Early Cretaceous rifting phase. Results of modelling of th e Lower Namurian oil system indicate that gas formed by secondary cracking of the oils can have mixed with the Westphalian coal-derived gas. Such a mi xing is inferred from geochemical analyses. The existence of a Lower Namuri an hydrocarbon system in the West Netherlands Basin implies that hydrocarbo ns are possibly trapped in the Westphalian and Namurian successions. These potential traps in the basin have not yet been explored.