Quantitative Characterization and Conceptual Modeling of a Heterogeneous Dinantian Carbonate Reservoir: Implications on the Associated Geothermal Energy Potential Assessment of the Luttelgeest Isolated Platform
Summary
The Carboniferous Dinantian carbonates of the Dutch onshore may be a target for ultradeep geothermal application. With a positive temperature anomaly of 150-200 ◦C at 4-5 km depth, geothermal energy generation from the Luttelgeest platform is an enterprise that could be considered. It comprises an isolated carbonate platform system, which is located in the Dutch onshore subsurface below the province of Flevoland and is encountered at 4355 to 5123 m depth. Only one well, Luttelgeest-01 (LTG-01) penetrates the succession. Previous work on the area has shown that the carbonates comprise a fine-grained, muddy matrix with an intergranular porosity close to 0% which initially would make fluid convection impossible. The margins, however, are heavily fractured and might provide pathways for fluid flow. In this study, the geothermal potential of the platform has been evaluated by the analysis of core, log, well data of LTG- 01, together with 2D seismic data and analogues. Firstly, the goal is to design a workflow and apply it to reach a set objective on these Dinantian carbonates, with the idea that the same workflow could be applied to similar cases elsewhere. Secondly, a conceptual model for fluid flow in the platform through a fault plane is proposed, as well as stratigraphic boundaries between sequence cycles in the platform. This model reveals the considerable possibilities of the Luttelgeest platform for ultra deep geothermal development.