Analytical Methods in Compositional Modeling

Speaker: Dr. Tara LaForce
Stanford UniversitySubsurface flow of several phases occurs in enhanced oil recovery (EOR), geological carbon dioxide storage, coal-bed methane production, and surfactant enhanced remediation of non-aqueous phase liquid contaminants in aquifers. The thermodynamic processes that allow for efficient flow of multiple fluids simultaneously are poorly understood, yet this knowledge is the key to developing a successful hydrocarbon production strategy. Using the method of characteristics (MOC) it is possible to construct analytical solutions to the conservation laws governing dispersion-free multicomponent, multiphase flow in one dimension. Analytical solutions provide insight into the behavior of multiphase flow and can also be used in streamline simulators and as benchmarks for traditional simulators. The first analytical solutions presented are for an analogue ternary system modeling gas injection into an oil reservoir. Three components are present and up to three phases may form. In this study the analytical solutions are compared to core flood data. The analytical solutions accurately predict core flood effluents for most of the experiments. A single set of relative permeability parameters is insufficient to model all of the experiments, indicating hysteresis in the relative permeabilities.Analytical solutions are also constructed to model surfactant enhanced remediation of a contaminated aquifer. Like the previous example up to three phases may form. Three realistic sets of relative permeability parameters are studied. The phase relative permeabilities have a substantial impact on the recovery efficiency. In some cases the recovery of oil declines with increasing surfactant in the injection mixture. Current research on four-component three-phase flow will be discussed. This extension of MOC theory is critical because at least four components are needed in order to accurately model CO2 or WAG injection into a water-flooded reservoir. Future analytical and numerical research into multiphase flow with adsorption and hysteresis and discuss further applications of MOC theory to coal-bed methane production, CO2 sequestration and EOR will also be proposed.

Location: Hedco Pertroleum and Chemical Engineering Building (HED) - 116

Audiences: Everyone Is Invited

Contact: Takimoto Idania