Fossil fuel production is growing annually by 2-3 million barrels per day, while for the development of industry it is necessary to maintain the rate of oil extraction, scientists from Tyumen State University (TSU) said.
Some countries are beginning to produce high-viscosity oil, the deposits of which have been less developed than conventional oil deposits. Since it flows out of the formation much more slowly, its extraction requires the use of special technologies, such as steam injection. The steam heats the oil, its viscosity decreases, and it flows better, scientists explained.
The steam-cyclic effect occurs in several stages. First, steam is pumped through a well into an oil formation, then the well is closed while the steam condenses in the formation, it is reopened and oil is produced. At the same time, the effectiveness of all stages of the technology directly depends on their duration, experts note.
Tyumen State University researchers have determined how much time is required for each stage of steam cyclic exposure to a formation with high-viscosity oil. They developed a special mathematical model for this technology.
“Our model, unlike others, does not require a large amount of input information through the use of balance relationships. To use it, you do not need to know the parameters at each point in the formation, and oil and gas companies do not have such information. Usually, with a fairly high error, the properties of only individual sections of the formation are known, from which rock samples were taken for research,” said Alexander Gilmanov, senior lecturer at the Department of Modeling of Physical Processes and Systems at Tyumen State University.
He emphasized that using the developed mathematical model, it is possible to determine the duration of the stages of steam-cyclic impact for given reservoir parameters for any field. The use of optimal technological parameters, according to the researchers’ calculations, makes it possible to produce more oil by approximately 10% per cycle at the same costs. Moreover, the development can be used in fields of any country.
In the future, scientists plan to simulate steam-cyclic effects using horizontal wells.