ABSTRACT
This paper aims to study the effect of different aqueous phases including deionized water (D.W), seawater (S.W), and carbonated seawater (C.W) on oil recovery and asphaltene precipitation during waterflooding in core samples from the Azadegan oil field, Ahvaz, Iran. In this regard, we present the outcomes of a series of coreflood experiments on this local reservoir from different aspects. Besides, a mathematical model using the PC-SAFT EoS was applied at different pressures to predict the asphaltene precipitation area at reservoir temperature. The asphaltene was extracted from crude oil and added to Saltrol® 220 to prepare synthetic oil samples with different asphaltene concentrations of 0 ppm, 500 ppm, and 1000 ppm. In the coreflooding experiments, C.W led to the highest permeability in asphaltene-free oil, while in the presence of asphaltene, S.W showed the greatest permeability. The highest recovery factor in absence of asphaltene was 57% achieved by C.W while the highest recovery factor in asphaltene-containing oil was 52.6% and 50.5% for oil with asphaltene concentrations of 500 ppm, and 1000 ppm, respectively, achieved by S.W injection. These outcomes show that S.W injection is a promising method for enhancing oil recovery in the Azadegan oil field and perhaps other carbonate reservoirs.
Nomenclature
aassoc | = | Association interactions |
achain | = | Chain formation |
adis | = | Dispersive attraction |
ahs | = | Hard-sphere energy per segment |
ASPext | = | Extracted asphaltene, ppm |
C.W | = | Carbonated seawater |
D.W | = | Deionized water |
EOR | = | Enhanced oil recovery |
EoS | = | Equation of state |
Sw | = | Initial water saturation, % |
Ka | = | Absolute permeability, mD |
Keff | = | Effective permeability, mD |
Kg | = | Gas permeability, mD |
Kr | = | Relative permeability, mD |
PC-SAFT | = | Perturbed-chainstatistical associating fluid theory |
PV | = | Pore volume, cm3 |
RF | = | Recovery factor, % |
S.W | = | Seawater |
SARA | = | Saturates, aromatics, resins, and asphaltenes |
VLLE | = | Vapor-liquid-liquid equilibrium |
φg | = | Gas porosity, % |
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Notes on contributors
Sina Bazyar
Sina Bazyar is a Ph.D. candidate in the department of Chemical Engineering, Marvdasht Islamic Azad University. His PhD research is about asphaltene precipitation during water flooding in carbonate oil reservoirs.
Moein Nabipour
Moein Nabipour is a PhD holder in Chemical Engineering and currently, he is working as the Assistant Professor of Chemical Engineering and head of the Chemical Engineering Department at the Marvdasht Islamic Azad University.
Amin Azdarpour
Amin Azdarpour is a PhD holder in Petroleum Engineering and currently, he is working as the Assistant Professor of Petroleum Engineering and head of the Petroleum Engineering Department at the Marvdasht Islamic Azad University.
Bizhan Honarvar
Bizhan Honarvar is a PhD holder in Chemical Engineering and currently, he is working as the Associate Professor of Chemical Engineering at the Marvdasht Islamic Azad University.
Nadia Esfandiari
Nadia Esfandiari is a PhD holder in Chemical Engineering and currently, he is working as the Assistant Professor of Chemical Engineering at the Marvdasht Islamic Azad University.