Scientists create catalyst based on weak acid salts to simplify high-viscosity oil production

Employees of the Laboratory of In-Situ Combustion of the Institute of Geology and Petroleum Technologies of Kazan Federal University have developed a catalyst based on salts of weak acids to increase the efficiency of heavy oil production.

The main difficulty that oil companies face when developing such oil is its high viscosity, due to the high content of resins and asphaltenes.

"At Kazan University, catalytic processes for upgrading of heavy oil are studied in order to create new technologies for field development," says lab head Alexey Vakhin. "For example, we recently found out how the composition of heavy oil changes under the combined effect of water vapor and carbon dioxide in the presence of water-soluble salts Na3VO4 (sodium orthovanadate), NaH2PO4 (sodium dihydrogen phosphate) and Na2H5P(W2O7)6 (sodium phosphotungstic acid (sodium pentahydro-12-tungstic phosphate).

The results of the study were published in the journal Energy Conversion and Management (IF 10.4)

"The use of salts of weak acids intensified the reactions of dehydrogenation, hydrogenation and isomerization of some of the resins and asphaltenes. This led to a decrease in their molecular weight and irreversibly reduced the viscosity of the oil," explains senior researcher Yasser Abdelsalam. "Sodium orthovanadate demonstrated the greatest efficiency in reducing the content of asphaltenes and the corresponding decrease in viscosity."

When using this catalyst, the volume of oil obtained increases by 35 percent. The asphaltene content in it decreased by 5 percent, and the viscosity at 20 degrees Celsius decreased by 72.8 percent. As for the sulfur content, it decreased by 41.2 percent.

According to Alexey Vakhin, the efficiency of in-situ catalysts depends on the characteristics of the deposit. For example, on the surface of carbonate rocks, their ability to affect oil increases.

"We are currently studying organosoluble and water-soluble compounds containing catalytically active metals," the scientist adds. "Previously, our laboratory staff created catalytic complexes for in-situ use based on transition metals. They have already been tested at a number of heavy oil fields and have shown high efficiency in increasing oil recovery."

The study participants are confident that the combination of carbon dioxide with water-soluble catalysts in catalytic aquathermolysis is a promising method for reducing the viscosity of heavy oil. It opens up new opportunities for increasing the recovery.

The study was carried out at the expense of funds from the subsidy allocated to Kazan Federal University to fulfill a state assignment in the field of scientific activity (project No. FZSM-2023-0014).

More information:
Mechanisms of CO2 and water soluble sodium-based catalysts in the aquathermolysis of heavy oil
www.sciencedirect.com/science/ … 0196890425005059?via%3Dihub

Provided by Kazan Federal University