High-viscosity oil is oil with a high content of asphaltenes, resins and other organic compounds. In order to extract it, hot vapor is injected into the oil formation, heating up the oil to make it more fluid. An alternative is catalytic thermolysis, a method involving the use of catalysts that make it possible to break down complex and heavy molecules of oil into lighter ones. As a result, oil becomes more suitable for extraction and further processing.
The scientists from Kazan University have improved catalytic thermolysis by creating several catalysts based on iron, nickel, cobalt, chromium and copper. To determine which sample is optimal, the authors tested the new compounds in laboratory conditions. They found that a catalyst based on copper tallate, a compound of copper and tallow acid or its derivatives, reduces oil viscosity by 2.6 times compared to the original samples. A catalyst based on a mixture of iron and nickel reduced the content of resins and other high-molecular compounds by 8%. Finally, iron tallate increased the concentration of light hydrocarbons by 17%.
The best-suited catalyst was a mixture of iron and nickel at an 85-15 ratio of iron to nickel. The authors tested the catalyst at the Aksenovskoye field in the Volga region, adding the catalyst to the formation before aquathermolysis. In the course of four months of testing, the water cut of the oil fell from 99% to 30%. Among other things, this made it possible to reduce the energy intensity of oil extraction.
“We plan to continue research to improve the composition of the catalyst and expand the scope of its application. In the future, this method could be used at other fields of high-viscosity oil, making their development more economically viable,” Irek Mukhamatdinov, candidate of technical sciences, is quoted as saying by Kazan University.
