New Developments in Hybrid Petroleum Migration Simulators

Hantschel, Thomas, Armin Kauerauf, Thomas Fuchs, Bjorn Wygrala, IES, Aachen, Germany

Several methods are used to simulate multi-phase petroleum flow in basin scale models and these are commonly described as Darcy flow, Flowpath and Invasion Percolation. All of these methods have been successfully applied and their strengths have been well document­ed, but all are also characterized by weaknesses which have limited their application and the quality of the results.

Fortunately, the weaknesses of one method can mostly be compensated by the strength of another method. As a result, attempts were made to link different methods in so-called Hybrid simulators. An early approach was in sequential Hybrid simulators where, for exam­ple, a full 3D pressure/ temperature/ maturity analysis is performed, followed by a separate simulation of petroleum migration using flowpath simulators.

So-called full Hybrids, in which Darcy and Flowpath modeling are closely coupled, were first introduced in 1999 and are now widely used in the industry, especially for full 3D mod­eling. These simulators have gone through a substantial refinement process and in addition to fully PVT-controlled n-component, 3-phase migration modeling, which is now a standard feature, the latest development stages are characterized by the following features:

- The simulators use all three migration modeling methods: Darcy is mainly used for migration processes in low-permeability units, Flowpath in highly permeable units, while Invasion Percolation is used to model migration in faults. All methods are fully coupled.

-Local grid refinement is applied as an extension of older tartan grid methods.

All of these features are available in full 3D simulators and applications in various explo­ration environments are used to demonstrate them.