A New Way Has Been Found to Increase Oil Recovery Factor During Reservoir Flooding
Scientists from Kazan Federal University have obtained new results in the field of physical and chemical hydrodynamics. They studied the effects of surface tension and contact angle on the adsorbed amount of surfactants. The Devon News Agency was informed about this by the press service of the Institute of Geology and Oil and Gas Technologies of KFU.
Adsorption refers to the deposition of active substances on the surface of particles. Substances and materials that have a large particle surface and are capable of absorbing active substances are called adsorbents. For example, activated carbon is one of them. Porous media also have good adsorption properties.
Kazan scientists were the first to study mass transfer processes in digital cores under conditions of multiphase flows characteristic of the combined flow of water and oil.
Waterflooding using surfactants is one of the most commonly used and effective methods for enhancing oil recovery (EOR) from reservoirs. Injecting water into the formation is accompanied by displacement of oil from the pore space and filling it with water. In this case, about 60% of the oil remains in the reservoir.
Surfactants act at the water-oil interface and help reduce interfacial tension. As a result, the number of mobile people increases, i.e. available to displace liquid hydrocarbon reserves. The oil recovery factor increases.
Understanding the role and strength of factors influencing the adsorption of surfactants during flooding of oil-saturated porous media allows us to minimize the loss of expensive reagents and save money.
“The popular and widely used sodium dodecyl sulfate, whose properties have been well studied, was tested as a surfactant,” said Timur ZAKIROV, associate professor of the department of mathematical methods in geology at IGiNGT.
The researchers found that increasing the contact angle leads to a significant increase in the adsorbed amount. It has been established that an increase in the initial interfacial tension contributes to the suppression of the adsorbed amount of surfactants.
Scientists have studied a water-soluble surfactant that does not mix with the displaced oil. Under such conditions, the amount adsorbed is determined by the contact surface area between the surfactant and the adsorbent particles.
In other words, mass transfer processes depend on the characteristics of the joint flow of water and oil. It has been proven that an increase in the wetting angle leads to an increase in the surface area of such contacts, and a decrease in interfacial tension leads to its suppression.
The results obtained are of a fundamental nature. They can also serve as a basis for predicting losses of valuable and expensive surfactants during field development and the design of EOR measures.
Earlier, the Devon news agency wrote that KFU had developed software for predicting catalyst absorption during oil displacement. Modeling dynamic adsorption under multiphase flow conditions allows us to predict the efficiency of in-situ upgrading of heavy oil.
