3-D Volume Reconstruction and Visualization of Delta Analogue Models: Applications to Seismic Interpretation

Edyta Frankowicz, Jonny E. Wu, Jose de Vera, Umar Ngala, and Ken R. McClay
Fault Dynamics Research Group, Royal Holloway, University of London, Egham, United Kingdom

Scaled analogue (sandbox) modelling has proved to be a useful tool for simulating the geometries and structural evolution of delta systems. Three-dimensional reconstructions of analogue models using seismic volume visualisation and interpretation software allow seismic interpretation techniques to be applied to understand stratal and fault geometries in their spatial context.

A series of scaled analogue models are used to simulate the differential loading of a ductile substrate by a lobe-shaped progradational delta wedge. The models developed a delta top extensional system linked to a contractional fold-thrust belt at the delta toe by gravity spreading. The shelf is characterised by regional and counter-regional growth faults, while an extensive counter-regional fault system is developed at the shelf-slope break with radial faults at the delta slope. The fold-thrust belt has an arcuate geometry in plan-view and is characterised by both basinward and landward-verging detachment folds and transported detachment folds. The folds are discontinuous and change vergence through complex linkage zones along-strike.

To analyse the fault architecture in 3D the models are serially sectioned, photographed and reconstructed into a digital 3D volume. Application of seismic attributes based on coherency detection to interpretation of physical models allows accurate and fast fault pattern recognition. Other attributes calculated using dip and azimuth information are useful in 3D interpretation of the top surface of the ductile substrate. Model results are compared to natural examples of fault systems in deltas and 3D models for reservoir scale fault systems are evaluated.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas