KFU researchers study enhanced oil recovery with ultrasound stimulation
“Our technology is based on a systematic consideration of poroelastic, filtration, and physicochemical processes occurring in a saturated porous medium under the influence of an elastic wave field. It differs from existing empirical approaches by providing a rigorous physical and mathematical justification and experimental verification,” informs Ruslan Kemalov, Associate Professor of the Department of Oil, Gas, and Carbon Materials Technology at the Institute of Geology and Petroleum Technologies and one of the authors of the article published in Neftegazovoe Delo.
He noted that Alfayaad Assim Gani Khashim, who defended a PhD thesis under his supervision in 2026, conducted comprehensive modeling and design of this innovative technology.
Dr Kemalov began researching acoustic stimulation of oil reservoirs back in 2007. For his project Innovative, Energy-Saving Technologies for Intensive Evaporation and Electromagnetic Activation in Heavy Oil Production and Processing, as part of a research team, he was awarded the State Prize of the Republic of Tatarstan in Science and Technology (2010).
“The first step in developing the technology was the creation of a mathematical model for elastic wave propagation in a saturated porous medium using the principles of poroelastic theory and two-phase filtration equations (oil-water), allowing for a quantitative assessment of the influence of acoustic impact parameters on changes in reservoir filtration and capacity properties. Numerical modeling algorithms were developed to calculate the distribution of pressure, saturation, and changes in the rheological properties of oil in the near-wellbore zone. Based on the model, a software package was implemented for predicting the process effect and selecting optimal impact parameters,” says Ruslan Kemalov.
A borehole acoustic emitter was created at Kazan Federal University. The device’s range is 50 meters, so it is recommended for use on small oil reservoirs, explains the scientist.
“Experimental studies conducted on oil samples and core material have shown that acoustic stimulation in the optimal frequency range (3 to 5 kilohertz) for 5 to 15 minutes leads to a decrease in oil viscosity by an average of 7 to 15 percent,” says Dinar Valiev, senior lecturer in the Department of Oil, Gas, and Carbon Materials Technology. “This process is accompanied by the disaggregation of asphaltene structures (they break down into smaller particles) and a change in the group composition of the oil dispersed system.”
The key, he explained, is cavitation microbubbles, which begin to form in large quantities under acoustic stimulation. What happens in the oil is reminiscent of boiling.
“It has been established that some structural changes in the oil dispersed system are irreversible, indicating a persistent modification of the supramolecular organization of the oil under the influence of an acoustic field,” adds Alim Kemalov, Head of the Department of Oil, Gas, and Carbon Materials Technology.
Based on the results of computational modeling and pilot field assessments, the predicted increase in well flow rate is up to 25-30 percent, depending on the initial filtration characteristics of the reservoir and the degree of degradation of the bottomhole zone.
“A method has been developed for quantitatively assessing changes in permeability, viscosity, and phase mobility under the influence of acoustic waves, allowing us to determine optimal treatment regimes depending on the physicochemical properties of the oil and reservoir parameters. The method enables preliminary prediction of the process effect without costly field testing and can be integrated into digital field development models,” Alim Kemalov continues.
Kazan Federal University has received two national patents – for a borehole acoustic emitter and for a method for enhancing oil production using low-frequency wave action.
The development is targeted at oil fields with high viscosity, low permeability, and high water cut. It can be used as part of a comprehensive enhanced oil recovery system without the use of chemical reagents or major well interventions.
These results provide the scientific and technical foundation for the implementation of wave technologies in the development of hard-to-recover reserves and expand our understanding of the mechanisms of acoustic action on the filtration and structural properties of oil systems.
