DTU Offshore is focusing on fracture forward modelling as part of the GO-Forward project. Building on our previous development of the DFM Generator software, we are applying advanced modelling techniques to carbonate and crystalline basement reservoirs.
Fractures and faults play a critical role in geothermal reservoirs, particularly in how they influence fluid flow. Key factors such as fracture density, size, aperture, and interconnections determine the flow performance in reservoirs with low matrix permeability. While fractures can enhance fluid flow, they can also act as barriers, impeding flow paths due to mineralization or fault movement. Additionally, these faults are potential sites for induced seismic events, which is a crucial factor to assess for seismic hazard analysis.
Mapping small-scale fractures is challenging due to the limitations of subsurface imaging and borehole data. Traditional methods rely on stochastic fracture models based on measured geometries from boreholes or analog outcrops. However, these methods struggle to accurately reflect variations in geological conditions, such as differences in lithology or deformation history.
To overcome these limitations, DTU Offshore is utilizing process-based geomechanical Fracture Forward Models (FFM). Our approach includes:
- Adapting the DFM Generator software to geothermal reservoir rock types, including basement rocks.
- Integrating geomechanical properties from stratigraphic layering and diagenetic alterations informed by Stratigraphic Forward Modelling (SFM) and Diagenetic Modelling (DGM).
- Incorporating tectonic stress histories and multiscale fault fabric, along with the effects of thermal and chemical changes over geological timescales and during reservoir exploitation.
- Using advanced machine learning techniques to improve data assimilation from seismic surveys, outcrop photogrammetry, and borehole images.
These methodological advancements aim to provide a more reliable and comprehensive workflow for creating multiscale fault and fracture models. This reduces uncertainty in pre-drill assessments of geothermal reservoirs, identifies potential flow barriers, and contributes valuable insights into seismic hazard analysis.
