STAR: A Geothermal Reservoir Simulation System

Abstract

The STAR simulation system is the fifth generation in a series of general and flexible computational tools for simulating multiphase, multicomponent transport of fluid mass and heat in three-dimensional slab, cylindrical or spherical geometry: two-dimensional Cartesian or ax symmetric geometry: or three dimensional Cartesian geometry. Considerable flexibility is provided for imposing various grid shapes, different types of boundary conditions, and realistic earth structure upon the finite difference grid. The code uses a fully implicit iterative technique to simultaneously solve the highly nonlinear equations expressing the overall heat balance and the multicomponent, multiphase mass conservation relations. The thermodynamic description of the multiphase multicomponent fluid in the porefractures of the rock is incorporated as a modular computer accessible equation of state package selected from the STAR program library. Postprocessors are incorporated in the system to facilitate the graphical presentation of computed results and to perform auxiliary calculations of the effects of reservoir phenomena upon other observable parameters such as the distribution of gravity anomaly.