Perm Polytechnic researchers studied how injection of carbon dioxide into oil reservoirs affects their structure. The results showed that this method can help reduce the greenhouse effect, but requires optimization to avoid blocking pores and reducing oil production.
The concentration of carbon dioxide in the atmosphere has increased by 11.4% over the past 20 years, exacerbating the greenhouse effect and global warming. One of the promising solutions to the problem is the capture and injection of CO2 into oil reservoirs, where the gas can be safely stored. However, the processes that occur during the interaction of carbon dioxide with rock and formation fluid are still insufficiently studied.
Perm Polytechnic scientists conducted an experiment to find out how CO2 injection affects the structure of the reservoir. They used a core – a rock sample that was scanned with a tomograph before and after saturation with carbon dioxide. The results showed that CO2 causes complex physicochemical reactions that initially increase formation porosity, but then lead to the formation of carbonate crystals that block the pores.
“First, carbon dioxide destroys the thin walls between the pores, increasing their size and permeability. However, later crystals of potassium and magnesium carbonate form, which block the pores and reduce permeability by 60-70%,” explains Dmitry Martyushev, professor at PNIPU.
The study will help optimize the process of injecting CO2 into oil reservoirs to reduce the greenhouse effect and increase the efficiency of oil production. The scientists plan to continue experiments to study the effects of flow rate and pressure on pore clogging.
Source: naked-science.ru
