Using Basin Modeling for Geothermal Energy Exploration in The Netherlands
S. Nelskamp and J. M. Verweij
TNO, Utrecht, The Netherlands
The petroleum geology of the West Netherlands Basin (WNB) and Roer Valley Graben (RVG) in the Netherlands has been studied in detail by several authors over the years (Zijerveld et al., 1992; Geluk et al., 1994; Van Balen et al., 2002). A lot of the geological research was focused on conventional oil and gas exploration. However, the focus of exploration currently shifts towards unconventional energy such as geothermal energy or shale gas. For geothermal purposes new questions with regard to porosity/permeability and temperature of sandstone aquifers and the related thermal conductivity have surfaced that were not answered by the previous studies. For example, more detailed knowledge of eroded thicknesses and the influence of the erosion on the geological framework is important for predicting porosity or permeability in sandstones and shales.
Geothermal energy in the Netherlands can be used for a number of applications, such as heating of greenhouses or office buildings. To assess the amount of energy that can be extracted from the earth using current technology, a tool was developed that displays available sandstone reservoirs, depth, temperature and flow properties of the layers (www.thermogis.nl). So far, the generated information is based on the present-day burial and a temperature gradient for the entire Netherlands. Temperature and porosity measurements are, however, only available at public well locations. The determination of these parameters on a regional level requires their estimation between the wells. Instead of an interpolation between the measured temperature and porosity values, we apply 3D basin modeling using PetroMod from Schlumberger to include the effect of present and past burial.
Within this study a burial anomaly map was created using the reconstructed thicknesses from the erosion maps and running a forward basin model. The burial anomaly is mainly related to the Late Cretaceous inversion event. In some areas the difference in burial compared to present-day is more than 1500m, indicating that significant differences in rock properties could occur. The burial anomaly is restricted to the northern part of the study area where highest values coincide with large inverted faults.
AAPG Search and Discovery Article #120098©2013 AAPG Hedberg Conference Petroleum Systems: Modeling the Past, Planning the Future, Nice, France, October 1-5, 2012