Abstract: Asphaltene simulation is performed by modeling asphaltene using physical changes. A pseudo-component framework is used to simulate asphaltene precipitation, asphaltene flocculation, and asphaltene deposition in a subsurface region. The pseudo-component framework for asphaltene simulation treats asphaltene precipitation, asphaltene flocculation, and asphaltene deposition as physical changes of a single component, rather than as chemical changes. Use of the pseudo-component framework for asphaltene simulation reduces complexity of asphaltene simulation. For example, use of the pseudo-component framework for asphaltene simulation enables tracking of asphaltene as it is found in different states (precipitated, flocculated, deposited). Use of the pseudo-component framework for asphaltene simulation enables chemical reactions to be replaced by a flash and adsorption framework. Asphaltene simulation using the pseudo-component framework exhibits stable and fast convergence.

Abstract: A method for simulating a microemulsion system in a chemical enhanced oil recovery process is disclosed. The method includes receiving a geological model of a subsurface reservoir that defines a grid having a plurality of cells, determining a surfactant concentration for each cell based on a volume of surfactant and a volume of water within the cell and independently from a volume of oil in the cell, and simulating fluids flowing in the subsurface reservoir. Results from simulation can be used to optimize a chemical enhanced oil recovery process in a subsurface reservoir.

Abstract: A method for simulating a microemulsion system in a chemical enhanced oil recovery process is disclosed. The method includes receiving a geological model of a subsurface reservoir that defines a grid having a plurality of cells, determining a surfactant concentration for each cell based on a volume of surfactant and a volume of water within the cell and independently from a volume of oil in the cell, and simulating fluids flowing in the subsurface reservoir. Results from simulation can be used to optimize a chemical enhanced oil recovery process in a subsurface reservoir.

Abstract: A method, system and computer program product is disclosed for using a constrained pressure residual (CPR) preconditioner to solve adjoint models. A linear system of fluid flow equations comprising a plurality of variables that represent fluid flow properties in a geological formation of a subterranean reservoir is provided. Matrix (Ã)T, which comprises a transpose of a Jacobian matrix associated with the linear system of fluid flow equations, is constructed. A constrained pressure residual preconditioner MCPRA?1 is constructed responsive to the matrix (Ã)T. Matrix equation (Ã)Ty=d is then solved using the constrained pressure residual preconditioner MCPRA?1.

Abstract: A method, system and computer program product is disclosed for using a constrained pressure residual (CPR) preconditioner to solve adjoint models. A linear system of fluid flow equations comprising a plurality of variables that represent fluid flow properties in a geological formation of a subterranean reservoir is provided. Matrix (Ã)T, which comprises a transpose of a Jacobian matrix associated with the linear system of fluid flow equations, is constructed. A constrained pressure residual preconditioner MCPRA?1 is constructed responsive to the matrix (Ã)T. Matrix equation (Ã)Ty=d is then solved using the constrained pressure residual preconditioner MCPRA?1.