PORTEC is a material balance model developed in-house by ESK to simulate gas storage processes in porous rock formations (depleted or partly depleted hydrocarbon reservoirs, aquifer structures). The software tool supports storage operators in their day-to-day business and assists subsurface engineers in planning and designing storage facilities. PORTEC consists of three linked modules (reservoir, wellbore and above-ground facility), representing all relevant hydrodynamic and thermodynamic processes during injection, withdrawal and shut-in periods from the manifold to the reservoir and vice versa.
The model covers all processes associated with gas storage operations in porous rock formations such as:
Reservoir module
- Pressure-volume relationships in the storage formation resulting from withdrawal/injection of gas
- Pressure changes in the storage layer due to aquifer influx
- Hydrodynamic communication between adjacent reservoir compartments
Well module
- Inflow performance (IPR)
- Vertical flow performance (VFP)
- Water cut versus production volumes and rates
Above-ground facility module
- Pressure losses along interconnecting lines between individual wellheads and a common manifold
- Input data such as reservoir parameters, well data, gas compositions etc. can be edited via an easy-to-use pre-processor (ParEdit). Instead of a detailed finalisation plan, single wells can also be characterised by means of appropriate performance figures generally interpreted from well test data.
- All calculation results can be displayed in table and chart view.