The conceptual framework of our work is the further development of dynamic stratigraphy. This means a process-oriented understanding of sedimentary units on different scales and its applications for predictions in the subsurface.
Characterisation and prediction of reservoir heterogeneities require a process understanding of the sedimentary architecture. We propose a simple, process-based methodology to analyse heterogeneities in a rigorously hierarchical way, moving from the smallest to the largest sedimentary units (particles to basins):
- Microscale heterogeneities: caused by particle and pore properties (size, composition, texture etc.) which are determined by depositional and diagenetic fluid dynamics.
- Mesoscale heterogeneities: caused by various stratification styles, which are controlled by the major depositional/erosional processes
- Macroscale heterogeneities: caused by facies and architectural elements, which record the differing dynamics and preservation of facies tracts
- Megascale heterogeneities: caused by fundamental sedimentary cycles and sequences, which reflect the stratigraphic dynamics of small-scale baselevel fluctuations
- Gigascale heterogeneities: caused by the stacking of fundamental cycles within a cycle hierarchy, which is controlled by long-term baselevel dynamics
Understanding the formative processes of each scale allows to deduce "rules" and predictions on the distribution of heterogeneities. A combination with petrophysical (porosity, permeability, gamma-ray logs) and geophysical tools (3-D georadar) in outcrop should lead to an integrated data set for reservoir modelling from microscopic to seismic scale.