In a paper printed within the journal Vitality & Fuels, a novel enhanced heavy oil restoration strategy was introduced by integrating a standard weak alkaline (sodium carbonate) alkaline–surfactant–polymer (ASP) flooding approach with silica nanoparticles.
Examine: Synergistic Results of Weak Alkaline–Surfactant–Polymer and SiO2 Nanoparticles Flooding on Enhanced Heavy Oil Restoration. Picture Credit score: nevodka/Shutterstock.com
This modern strategy has the potential to enhance oil restoration, reduce prices of chemical brokers, and remove alkali deposits and formation erosion.
The Want for Enhanced Heavy Oil Restoration
With the event of conventional reservoirs of their latter phases, the water content material in generated fluids stays giant, culminating in a quick drop in reservoir output. After secondary manufacturing, fewer than 15% of the pure reserves had been retrieved as a result of the undesirable oil-water motion ratio throughout injection, wettability of reservoirs, and heterogeneous nature.
In consequence, it’s essential to use trendy applied sciences to the at present exhausted reservoirs. The usage of chemical reagents on this area is considered the best tertiary methodology for enhanced heavy oil restoration.
Alkaline-Surfactant-Polymer Methods
Tertiary recovery methods, notably ASP procedures, have proven to be successful chemically enhanced heavy oil recovery processes in certain reservoirs. An ASP technique integrates higher macro-scale swept polymer efficiency as a result of decreased injected water movement with improved micro-scale displacement effectiveness of surfactants (in situ as well as additive saponification).
In contrast with the water injection technique, enhanced heavy oil recovery offered by ASP solution injections technique may be as much as 20% higher.
Nanoparticles in Heavy Oil Recovery Techniques
Combining classical chemical reagents (polymer/surfactant flooding) with nanoparticles has been suggested as an enhanced heavy oil recovery technique.
A polymeric nanofluid is composed of NPs and a polymeric solution. Owing to the lower water-oil movement ratio and the higher displacement oil efficacy, polymeric nanofluids are gaining popularity.
The adsorption of hydrogen bonds and charges among NPs and polymeric molecules boosts the rheological characteristics of the polymeric nanofluid, making it much more resistant to salt and heat.
Research suggests that electrostatic repulsive forces may limit the binding of polymer-grafted hydrophilic NPs on the hydrophobic rock surface. NPs have been shown to boost oil production by modifying the wettability of rock surfaces and lowering interfacial tension.
Limitations of ASP Methods
While ASP processes provide numerous benefits with respect to enhanced heavy oil recovery, higher alkali levels may also produce issues, like alkali scale deterioration, higher expenses, and a significant reduction of the pump-checking cycle.
Addressing these obstacles is crucial for lowering operating costs and enhancing oil recovery effectiveness. Keeping this in view, the team developed a multi-composite flooding approach that combines ASP with silica NPs.
Findings of the Study
The synergistic effects of ASP with silica NPs were carefully investigated using static testing, core displacement testing, and microfluid experiments.
The ASP and ASP/silica solution’s interfacial tension values remained low. A mildly alkaline ASP changed the wettability of the rock surface from lipophilicity to weak hydrophilicity. In comparison, the mildly alkaline ASP/silica mixture could quickly convert the neutral wettability of a rock surface to high hydrophilicity.
The recovery of oil improved by 6.67 percent when ASP/silica nanoparticle mixtures were used following water flooding, in comparison with ASP-only solutions. The ASP/silica mixture outperformed the ASP mixture in terms of swept volume and displacement efficiency.
The ASP/silica mixture performed better in emulsification and snap-off compared to a hydrolyzed polyacrylamide/ASP mixture. Droplets of ASP emulsion were more likely to agglomerate, suggesting low thermodynamic stability.
Despite the fact that the ASP/silica droplets collided and distorted extensively, no agglomeration was observed, indicating high thermodynamic, viscoelastic, and kinetic stabilities.
As the silica NPs bound on the emulsion surfaces may act as a deterrent to agglomeration, the emulsion’s stability was improved. Greater stability translates to higher microforce acting on a droplet of oil.
Oil droplets were, therefore, more readily pushed and drawn out by emulsion droplets. It showed that the ASP/silica emulsion extracts more oil.
Reference
Wang, W., Peng, Y., Chen, Z., Liu, H., Fan, J., & Liu, Y. (2022). Synergistic Effects of Weak Alkaline–Surfactant–Polymer and SiO2 Nanoparticles Flooding on Enhanced Heavy Oil Recovery. Energy & Fuels. Available at: https://doi.org/10.1021/acs.energyfuels.2c01096
