TITLE:
Experimental Evaluation of the Mobility Profile of Enhanced Oil Recovery Gases
AUTHORS:
Ofasa Abunumah, Priscilla Ogunlude, Edward Gobina
KEYWORDS:
Mobility, Viscosity, Permeability, Oil, Gas, Reservoir Characterization, EOR Displacement
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.11 No.2,
April
12,
2021
ABSTRACT: The mobility profiles of gases used in enhanced oil
recovery (EOR) have been thoroughly investigated through the coupling
operations of data mining of oilfield data and experimental data analyses.
Mobility as an EOR objective function has not been previously applied to
characterize potential reservoirs for EOR selection and application, even
though it is a robust combinatorial function that benefits from two
petrophysical variables, permeability and viscosity. The data mining approach
identified mobility as a reliable objective function for reservoir
characterisation. The data distribution and clustering results indicate that Gas EOR reservoirs have
relatively higher mean mobility than Thermal, Microbial and Chemical EOR
reservoirs. The experimental approach investigated EOR gases, CO2,
CH4, N2, and Air. A modified Darcy Equation of State for
gas flow through porous media was applied to evaluate which gas would
competitively attain the oil displacement optimisation criterion for mobility
ratio, M ≤ 1. Coupling the data mining with the experimental data results
reveals that gas reservoirs can be further categorized by mobility. CH4 (18.16 mD/cp) was observed to have the
highest mobility followed by Air (14.60 mD/cp),
N2 (13.61 mD/cp), and CO2 (12.96 mD/cp). The gas mobility order
significantly corresponds with the mobility distribution of reservoirs that
implemented gas EOR processes. It was concluded that CO2 offers
relatively lower mobility, therefore, it is the most competitive EOR gas to
approach the mobility ratio criterion of unity or less.