Browsing by Subject "Non-Newtonian fluid"
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Item Commercial scale simulations of surfactant/polymer flooding(2012-08) Yuan, Changli; Delshad, Mojdeh; Wheeler, Mary F. (Mary Fanett); Balhoff, Matthew T.; Arbogast, Todd J.; Dean, Rick H.The depletion of oil reserves and higher oil prices has made chemical enhanced oil recovery (EOR) methods more attractive in recent years. Because of geological heterogeneity, unfavorable mobility ratio, and capillary forces, conventional oil recovery (including water flooding) leaves behind much oil in reservoir, often as much as 70% OOIP (original oil in place). Surfactant/polymer flooding targets these bypassed oil left after waterflood by reducing water mobility and oil/water interfacial tension. The complexity and uncertainty of reservoir characterization make the design and implementation of a robust and effective surfactant/polymer flooding to be quite challenging. Accurate numerical simulation prior to the field surfactant/polymer flooding is essential for a successful design and implementation of surfactant/polymer flooding. A recently developed unified polymer viscosity model was implemented into our existing polymer module within our in-house reservoir simulator, the Implicit Parallel Accurate Reservoir Simulator (IPARS). The new viscosity model is capable of simulating not only the Newtonian and shear-thinning rheology of polymer solution but also the shear-thickening behavior, which may occur near the wellbore with high injection rates when high molecular weight Partially Hydrolyzed Acrylamide (HPAM) polymers are injected. We have added a full capability of surfactant/polymer flooding to TRCHEM module of IPARS using a simplified but mechanistic and user-friendly approach for modeling surfactant/water/oil phase behavior. The features of surfactant module include: 1) surfactant component transport in porous media; 2) surfactant adsorption on the rock; 3) surfactant/oil/water phase behavior transitioned with salinity of Type II(-), Type III, and Type II(+) phase behaviors; 4) compositional microemulsion phase viscosity correlation and 5) relative permeabilities based on the trapping number. With the parallel capability of IPARS, commercial scale simulation of surfactant/polymer flooding becomes practical and affordable. Several numerical examples are presented in this dissertation. The results of surfactant/polymer flood are verified by comparing with the results obtained from UTCHEM, a three-dimensional chemical flood simulator developed at the University of Texas at Austin. The parallel capability and scalability are also demonstrated.Item Modeling of debris flows and induced phenomena with non-Newtonian fluid models(2015-12) Jeon, Chan-Hoo; Hodges, Ben R.; McKinney, Daene C; Liljestrand, Howard M; Moser, Robert D; Sepehrnoori, KamyDebris flows contain inhomogeneous distributions of solids within a liquid. By considering a mixture of solid and liquid forming debris flows as a non-Newtonian continuous liquid, the viscosity term for rheological models is simply constructed in the Navier-Stokes equations. Time-independent models (e.g. Herschel-Bulkely) for viscosity have been widely used, but there is an open question as to whether time-dependent models might provide improved results. In this work, both time-dependent and time-independent non-Newtonian fluid models are taken into account in simulation. Since debris flow induced phenomena include two or more interfaces, the level set method for multiple materials is applied as the interface tracking method. The numerical model is applied to two-dimensional test cases to validate this approach and analyze the relative importance of the viscosity model. The simulation results for the two models show reasonable agreement with available experimental data in most cases, however, time-dependent model only shows good correlation with experimental measurements for special case. It indicates that debris flows and induced phenomena could be simulated by the approach of this research and the time-dependent model is more adequate for representing real debris flows than time-independent models.Item Simulations of subsurface multiphase flow including polymer flooding in oil reservoirs and infiltration in vadose zone(2009-12) Yuan, Changli; Delshad, Mojdeh; Wheeler, Mary F. (Mary Fanett)With the depletion of oil reserves and increase in oil price, the enhanced oil recovery methods such as polymer flooding to increase oil production from water flooded fields are becoming more attractive. Effective design of these processes is challenging because the polymer chemistry has a strong effect on reaction and fluid rheology, which in turn has a strong effect on fluid transport. We have implemented a well-established polymer model within the Implicit Parallel Accurate Reservoir Simulator (IPARS), which enables parallel simulation of non-Newtonian fluid flow through porous media. The following properties of polymer solution are modeled in this work: 1) polymer adsorption; 2) polymer viscosity as a function of salinity, hardness, polymer concentration, and shear rate; 3) permeability reduction; 4) inaccessible pore volume. IPARS enables field-scale polymer flooding simulation with its parallel computation capability. In this thesis, several numerical examples are presented. The result of polymer module is verified by UTCHEM, a three-dimensional chemical flood simulator developed at the University of Texas at Austin. The parallel capability is also tested. The influence of different shear rate calculations is investigated in homogeneous and heterogeneous reservoirs. We observed that the wellbore velocity calculation instead of Darcy velocity reduces the grid effect for coarse mesh. We noted that the injection bottom hole pressure is very sensitive to the shear rate calculation. However, cumulative oil recovery and overall oil saturation appear to not be sensitive to grid and shear rate calculation for same reservoir. There are two models to model the ground water infiltration in vadose zone. One is Richard’s Equation (RE) model. And the other is two-phase flow model. In this work, we compare the two-phase model with an RE model to ascertain, under common scenarios such as infiltration or injection of water into initially dry soils, the similarities and differences in solutions behaviors, the ability of each model to simulate such infiltration processes under realistic scenarios, and to investigate the numerical efficiencies and difficulties which arise in these models. Six different data sets were assembled as benchmark infiltration problems in the unsaturated zone. The comparison shows that two-phase model holds for general porous media and is not limited by several assumptions that must be made for the RE formulation, while RE is applicable only for shallow regions (vadose) that are only several meters in depth and a fully saturated bottom boundary condition must be assumed.