Timing and Distribution of Biogenic Gas Generation in the Shallow Gas Play in the Dutch Offshore

Shallow gas accumulations in the Plio-Pleistocene Eridanos Delta deposits in the Dutch offshore are a valuable additional hydrocarbon source. Ongoing studies focus on better understanding the shallow gas play. The focus of this paper is on increasing the understanding of the origin of the shallow gas. For that purpose we used integrated modeling approaches to assess the timing and spatial distribution of biogenic gas generation. It was found that intra-Eridanos Delta deposits are the most probable source of biogenic gas and that these biogenic sources are at maximum depth and temperature today. Detailed glacial-interglacial temperature fluctuations do not have a large influence on the history of the optimum window for biogenic gas generation, i.e. on start of biogenic gas generation. In the oldest and deepest buried units of the Delta, biogenic gas generation started already at the beginning of the Pleistocene, while the youngest units have not yet reached the optimum window for biogenic gas generation.