Black Oil &
Unconventional Simulator

IMEX, one of the world's fastest black oil simulators, is used to model primary and secondary oil recovery processes in conventional and unconventional reservoirs.

A Semi-Implicit Approach for Integrated Reservoir and Surface Network Simulation
SPE 163615-MS

Conventionally, methods of coupling reservoirs and surface networks are categorized into implicit and explicit approaches. The term implicit coupling indicates the two simulators solve unknowns together, simultaneously or iteratively. While explicit coupling indicates the two simulators solve unknowns sequentially and exchange their boundary conditions at the last coupled time tn.

The explicit approach is straightforward to implement in existing reservoir and surface network models and is widely used. Explicit coupling does have drawbacks, however; as well rate and pressure oscillations are often observed.

In this paper, a new semi-implicit method for coupled simulation is presented. This technique stabilizes and improves the accuracy of the coupled model. The semi-implicit coupling overcomes the problems found in explicit coupling methods without requiring the complexity of a fully implicit coupled model.

Applications of the new approach are presented which show significant improvements over explicit coupling in both stability and accuracy.


© Copyright 2013. Society of Petroleum Engineers
Presented at the SPE Reservoir Simulation Symposium, 18-20 February 2013, The Woodlands, Texas