Abstract. The considerable decline of conventional oil and gas
reserves and respectively their production introduces new challenges to the
energy industry. It resulted in the involvement of hard-to-recover reserves
using advanced enhanced oil recovery (EOR) techniques. Thermal methods of
EOR are recognized as most technically and commercially developed methods
for the highly viscous crude oil. High-Pressure Air Injection (HPAI) is one
of the thermal production methods that reduce oil viscosity and increases
recovery. HPAI has already been effectively applied for different types of
reservoirs development and proven to be economically feasible.
The application performance of the HPAI technology strongly depends on the
quality of experimental and numerical modeling conducted on the target
object basis. Before the field tests, physicochemical and thermodynamic
characteristics of the process were studied. Further consequent numerical
modeling of laboratory-scale oxidation experiments and field-scale
simulation was conducted to estimate HPAI method feasibility based on the
results of oxidation studies. A medium pressure combustion tube (MPCT)
oxidation experiment was carried out to provide stoichiometry of the
reactions and field design parameters. A 3D numerical model of the MPCT
experiment was constructed taking into account the multilayer design,
thermal properties, heating regimes, and reaction model. The “history”
matched parameters such as fluid production masses and volumes, temperature
profiles along the tubes at different times and produced gas composition
demonstrated good correspondence with experimental results. The results
obtained during the experiment and modeling of MPCT (fluid properties,
relative phase permeability, kinetic model, technological parameters) were
used in field-scale modeling using various thermal EOR scenarios. Air
breakthrough into production wells was observed, thus a 2 % oxygen
concentration limit where implied. The overall performance of four different
scenarios was compared within 30 years timeframe. The development system was
also examined to achieve the maximum economic indicators with the
identifications of risks and main uncertainties.
Evaluation of the subject geological area suitability for oil recovery by High-Pressure Air Injection method
