A new approach for numerical modeling of a set of compositional dynamic models of oil and gas fields coupled by the same surface network is considered. A unified coupled system of equations is constructed to jointly model reservoir and surface network processes in the method proposed.
A new integrated model "reservoir-well-surface network" is a unified system of equations that includes a description of the physical processes in the reservoir, frictional and static pressure losses in wells and the surface network. The model includes technological constraints induced by well operation modes and surface network equipment. The unified system is solved fully implicitly at each time step.
The fluid model can be described both with tables in Black Oil format or with equations of state. If several fields with compositional fluid models are coupled by one surface network then specially designed algorithm is applied to automatically derive a single equation of state. The latter is then used to calculate the fluids properties of the mixture in the surface network.