Abstract
The surface-subsurface-coupled,2-phase,3-dimensional fluid flow simulator was applied for numerical simulation of surface and groundwater flow in the vicinity of underground oil storage plant (Koji Plant).
Complex geological, hydrological and hydrogeological structure conditions, and various artificial factors such as storage caverns and tunnels were all considered in this model. The simulation was carried out incorporating the excavation of the caverns and all other works such as oil-in operation. A large amount of geological, hydrological and hydrogeological information have been acquired around the plant since the preparatory stage of construction. These information were considered thoroughly on the development of the simulation model.
Various observed data such as inflow rate into the tunnels and caverns, injection rate into the water sealing tunnels, river flow rate and groundwater level in the borehals were matched in time series with the calculated values in order to optimize this simulation model.
Satisfactory matching was obtained between measured and calculated values by the simulation. The hydrological and hydrogeological simulation model developed in this study is capable of representing the various conditions of the surface and groundwater flow over the long term from the stage of construction to the stage of operation. It is considered that this model is sufficiently accurate for use in predicting the surface and subsurface flow around the Kuji plant in the future. The results have led to useful understanding of the mechanism of subsurface flow.
