Abstract
Probabilistic techniques are being increasingly used for modelling reservoir heterogeneity. A wide variety of models are now available, which all differ in their underlying assumptions, range of application, complexity of usage and computer efficiency.
Each technique has its own unconditional supporters. However, for the non-specialist, choosing one method is not trivial. Which method is best suited to a particular modelling context? After all, does it really matters from a practical, engineering point of view?
These are the basic questions we are addressing here.
After a review of current heterogeneity modelling techniques, a few "classical" models are compared on data from a deep-sea-fan reservoir. Fine scale, three dimensional distributions of permeability are generated using Indicator Simulations, Gaussian/Fractal Simulations and Truncated Gaussian Simulations. Common well log data and geological a priori are used for all methods.
The models are then compared in terms of connectivity and distribution of average permeabilities at the scale of full-field flow simulation grid.
Connected pore volume geometry on fine grids is found to be quite sensitive to the modelling technique. After upscaling, large scale permeability distributions remain sensibly different. The choice of the stochastic modelling technique has therefore a potentially important, practical impact on reservoir description.
