Unlocking Geothermal Potential in Brussels Sandstone Member
For Energie Beheer Nederland, we examined the geothermal prospects of the Eocene Brussels Sandstone Member (BSM) in southwest Netherlands. Our team analyzed well data, core samples, and seismic surveys to assess reservoir quality, focusing on porosity, permeability, and thermal parameters. We developed an updated static reservoir model revealing better constrained flow properties and improved economic potential compared to previous estimates. This study lays groundwork for future project design and operational planning to harness sustainable energy in the area.
Project Highlights
- Detailed analysis of new and offset wells enhanced reservoir understanding
- Thorough QA/QC of existing seismic surveys and interpretations of the BSM
- Developed a static model integrating petrophysical and seismic data
- Revealed higher geothermal flow rates and power output than expected
Challenges
Log Data Variability and Quality: Posed difficulties due to differing petrophysical signatures of subzones of the BSM (i.e. the presence of a glauconitic zone in the reservoir resulted in false clay signatures). This required careful reconciliation between the different logging tracks to obtain a sound assessment of permeability.
Well Test Data Was Not Easily Matched: With core-derived porosity-permeability behavior. Alternative upscaling algorithms were required to correctly capture the presence of thin highly permeable streaks in the bottom part of the reservoir.
Economic Feasibility Assessment: Needed reliable projections of production rates and thermal capacity to justify investment. Prior models did not assume well concepts that were fit-for-purpose for a shallow reservoir with high anisotropy like the BSM.
Well Test Data Was Not Easily Matched: With core-derived porosity-permeability behavior. Alternative upscaling algorithms were required to correctly capture the presence of thin highly permeable streaks in the bottom part of the reservoir.
Economic Feasibility Assessment: Needed reliable projections of production rates and thermal capacity to justify investment. Prior models did not assume well concepts that were fit-for-purpose for a shallow reservoir with high anisotropy like the BSM.
Solutions
Integrated Multi-disciplinary Approach: Combined geological, petrophysical, and geophysical expertise to analyze recent well data and seismic surveys. This enabled a robust evaluation tailored to subsurface conditions that considered reservoir heterogeneity and temperature gradients.
Customized Static Reservoir Modeling: Structured the area's subsurface information into a detailed framework showing reservoir geometry, facies distribution, and achieving high enough vertical resolution to capture sources of anisotropy.
Collaborative Validation Process: Involved iterative comparison with prior models and continuous refinement based on new petrophysical findings. Engaging client experts ensured clarity and confidence in results, building trust for future development decisions.
Customized Static Reservoir Modeling: Structured the area's subsurface information into a detailed framework showing reservoir geometry, facies distribution, and achieving high enough vertical resolution to capture sources of anisotropy.
Collaborative Validation Process: Involved iterative comparison with prior models and continuous refinement based on new petrophysical findings. Engaging client experts ensured clarity and confidence in results, building trust for future development decisions.
Values
Increased Confidence in Geothermal Potential: Gave the client assurance through improved reservoir data and productivity estimates. This supports stronger decision-making for exploration investments.
Results Can Be Widely Used for Planning Purposes: As the geothermal capacity maps were generated using surface plant location rather than subsurface location as a reference. Suitable well outstep assumptions lead to an optimization of subsurface well trajectories for each surface location.
Reduction in Drilling and Operational Risks: Via implementation of lessons learned in previous geothermal projects in the MSB in the capacity calculations, such as the choice to model strongly deviated rather than (sub-)horizontal wells, and the assumption of corrosion resistant well materials.
Results Can Be Widely Used for Planning Purposes: As the geothermal capacity maps were generated using surface plant location rather than subsurface location as a reference. Suitable well outstep assumptions lead to an optimization of subsurface well trajectories for each surface location.
Reduction in Drilling and Operational Risks: Via implementation of lessons learned in previous geothermal projects in the MSB in the capacity calculations, such as the choice to model strongly deviated rather than (sub-)horizontal wells, and the assumption of corrosion resistant well materials.