Fault geometry and architecture, insights from outcrop and seismic data

Geoscience Seminar by Dr Anita Torabi (NORCE Energy, Bergen, Norway)

Fault geometry and architecture, insights from outcrop and seismic data

Dr Anita Torabi, NORCE Energy, Bergen, Norway; anita.torabi@norceresearch.no

Faults play a significant role in controlling the migration and trapping of hydrocarbons. Thus, providing a rigorous and reliable assessment of fault network configuration and properties can considerably reduce the exploration risks and production challenges associated with fault-bound traps (Knai and Knipe, 1998; Ottesen et al., 2005). Fault geometric attributes include fault shape, fault displacement, length, damage zone width and fault core thickness (Caine et al., 1996; Torabi and Berg, 2011). Currently, there are uncertainties in defining fault 3D geometry and shape. These uncertainties are to some extent related to the methodological constraints, utilizing biased data and the accessibility and quantifications of the fault attributes. Usually, 3D fault shapes are reconstructed from 2D profiles obtained from seismic interpretation, outcrop or mine studies of fault sections (e.g. Lohr et al., 2008). Details of fault damage zone and fault core structures can be mapped at outcrop, but descriptions and statistical handling are usually constrained by how these features are defined by individual workers and their accessibility in the field.

Reflection seismic data is used to study subsurface faults, although the interpretation of faults could be affected by the seismic resolution (Marchal et al., 2003; Lohr et al., 2008; Iacopini et al., 2016; Torabi et al., 2016). By integrating spectral decomposition with seismic attribute workflows (e.g. coherence, dip, or fault enhancement attributes) we created new fault attribute volumes, which considerably enhanced fault images. We applied the method on a series of seismic volumes from the Norwegian Sea and the Barents Sea. The fault enhanced images had such a high resolution which enabled us to detect, and map fault damaged zone (fault damage zone plus fault core in outcrop scale) in seismic data. The mapped features on the fault damaged zone have been correlated with similar features mapped on outcrops (Alaei and Torabi, 2017).

In addition to the improved fault imaging on seismic data, we have extracted fault geometric attributes such as segment length and displacement directly from fault images in the fault attribute volumes. We used the extracted fault geometrical data to study the 3D shape and displacement distribution of faults (Torabi et al., 2019). Finally, we compared the scaling relations between the fault geometric attributes obtained from seismic with the corresponding attributes in the outcrop.

Alaei, B., Torabi, A., 2017. Seismic imaging of fault damage zone and its scaling relation with displacement.
Interpretation 5, 4, SP83-SP93.
Caine, J. S., Evans, J. P., and Forster, C. B. 1996. Fault zone architecture and permeability structure. Geology, 24,


Dr Anita Torabi is Principal researcher and Geoscience research leader at NORCE Energy in Bergen, Norway. She holds a Ph.D. in geoscience from the University of Bergen, Norway (2008). Her main research activities include the mechanism and mechanics of faulting; fault-related folding; fluid flow in deformed reservoirs; and diagenesis in fault zone with application to petroleum reservoirs, CO2 storage underground; geothermal reservoirs, geohazards and seismicity.