A General Unstructured-Grid, Equation-of-State-Based, Fully Implicit Thermal Simulator for Complex Reservoir Processes

Abstract

Summary This paper describes a general unstructured-grid, equation-ofstate-(EOS) based, fully implicit thermal simulator for complex reservoir processes. Under the unstructured grid framework, the simulator uses Newton's method to solve component material-balance equations, energy-balance equation, and volume-balance equation for component moles, energy, and pressure, where chemical reactions and external heat sources/sinks are treated in source terms. Because of the similarity among component material-balance equations and the energy-balance equation, energy is treated as a "component" to achieve a uniform formulation with common code for all simulations (black-oil, compositional, and thermal). The thermal simulator was validated using analytical models and other thermal simulators. The thermal simulator is used to study grid-orientation problems and to design and optimize Cold Lake heavy-oil development.