Polymer flooding is one of the most used chemical enhanced
oil
recovery (CEOR) technologies worldwide. Because of its commercial
success at the field scale, there has been an increasing interest
to expand its applicability to more unfavorable mobility ratio conditions,
such as more viscous oil. Therefore, an important requirement of success
is to find a set of design parameters that balance material requirements
and petroleum recovery benefits in a cost-effective manner. Then,
prediction of oil recovery turns out to handle more detailed information
and time-consuming field reservoir simulation. Thus, for an effective
enhanced oil recovery project management, a quick and feasible tool
is needed to identify projects for polymer flooding applications,
without giving up key physical and chemical phenomena related to the
recovery process and avoiding activities or projects that have no
hope of achieving adequate profitability. A detailed one-dimensional
mathematical model for multiphase compositional polymer flooding is
presented. The mathematical formulation is based on fractional flow
theory, and as a function of fluid saturation and chemical compositions,
it considers phenomena such as rheology behavior (shear thinning and
shear thickening), salinity variations, permeability reduction, and
polymer adsorption. Moreover, by setting proper boundary and initial
conditions, the formulation can model different polymer injection
strategies such as slug or continuous injection. A numerical model
based on finite-difference formulation with a fully implicit scheme
was derived to solve the system of nonlinear equations. The validation
of the numerical algorithm is verified through analytical solutions,
coreflood laboratory experiments, and a CMG-STARS numerical model
for waterflooding and polymer flooding. In this work, key aspects
to be considered for optimum strategies that would help increase polymer
flooding effectiveness are also investigated. For that purpose, the
simulation tool developed is used to analyze the effects of polymer
and salinity concentrations, the dependence of apparent aqueous viscosity
on the shear rate, permeability reduction, reversible–irreversible
polymer adsorption, polymer injection strategies on petroleum recovery,
and the flow dynamics along porous media. The practical tool and analysis
help connect math with physics, facilitating the upscaling from laboratory
observations to field application with a better-fitted numerical simulation
model, that contributes to determine favorable scenarios, and thus,
it could assist engineers to understand how key parameters affect
oil recovery without performing time-consuming CEOR simulations.