Russian oil company Tatneft is developing technologies for more active use of carbon dioxide generated during oil production, Azat Zaripov, First Deputy Director of the TatNIPIneft Research Institute, said in an article published in the company newspaper Neftyanye Vesti.
“A comprehensive project focused on carbon dioxide is being implemented at the TatNIPIneft Research Institute. CO₂ is as essential to life on Earth as water. At the same time, in recent years there has been growing discussion that excessive concentrations of CO₂ in the atmosphere may lead to global temperature increases, as the gas plays a key role in heat exchange. Therefore, certain CO₂ levels may disrupt the Earth’s climate balance,” the scientist noted.
This has prompted the search for new technologies for capturing and utilizing CO₂ throughout the value chain, from production to the creation of new products.
The approach involves chemical capture of CO₂ from flue gases using amine solutions. Part of the captured CO₂ is then used for enhanced oil recovery. The company conducted its first pilot tests at the Yelabuga field. Injection of CO₂ into mature wells with an initial water cut of 93% resulted in a sevenfold increase in oil production and a reduction in water cut to 20%.
Tatneft has also implemented large-scale CO₂ injection technology at the Biklyanskoye field. As a result, the oil recovery factor increased by 15%.
“Another application of CO₂ is its injection into heavy oil reservoirs to improve production efficiency. Liquid CO₂ readily dissolves in oil, significantly reducing its viscosity. Depending on reservoir characteristics, the oil recovery factor is expected to increase by up to 10% on average,” Zaripov wrote.
Another portion of CO₂ will be stored in underground geological formations. The gas will be compressed to the required pressure before injection into aquifers.
“As part of the CO₂ storage project, our laboratory conducts various experiments to study CO₂ filtration processes in geological formations. We injected carbon dioxide into core samples and assessed the volume of pore space it occupies when creating underground storage. During injection, CO₂ displaces formation water and occupies the freed pore volume. We also evaluated pressure changes and studied the impact of CO₂ on minerals, concluding that there is no risk of their dissolution,” said Oleg Sotnikov, Head of the Wells, Reservoirs and Hydrocarbons Department at TatNIPIneft.
”We already identified microorganism strains capable of not only surviving in medium with high СО2 concentration, but of reproducing and consuming gas converting it into valuable feedstock – methane, acetic acid and others. As a result, we get green circular economy”, Zaripov noted.
Pilot testing and industrial implementation of these technologies may expand CO₂ utilization and support the transition to carbon-neutral energy.
