Keywords: surfactants

Study of temperature and salinity effect on encapsulated surfactants ability to alter wettability and decrease interfacial tension

https://doi.org/10.58224/2619-0575-2024-7-4-87-103
Abstract
In recent decades, the task of increasing the oil recovery factor from productive formations has not lost its relevance. Today, there is a rapidly growing interest in the use of chemical methods to increase oil recovery to enhance production, in particular, using surfactants. To overcome the problem of high adsorption, which prevents the widespread introduction of surfactant flooding in carbonate formations, it is proposed to use the technology of encapsulating surfactants in a solid shell. Thus, the active substance can cover a large part of the reservoir, and therefore more oil can be extracted by injecting surfactants. In this work, the influence of typical reservoir conditions (high temperature and salinity) on the main properties of the dispersions of encapsulated surfactants, namely, a decrease in interfacial tension and a change in wettability, was studied. It is shown that the application of the encapsulation method preserves the necessary properties of surfactants, at which low interfacial tension is observed, and the surface of the carbonate rock becomes more hydrophilic.
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Overview of surfactant flooding as a method of increasing oil recovery and the applicability of microcapsulation technology to improve the efficiency of surfactant flooding

Abstract
The problem of increasing the degree of oil recovery from reservoir formations has remained relevant over the past few decades.
Currently, there is a rapid increase in interest in chemical methods of increasing oil recovery to intensify oil production, in particular, flooding with surfactants (surfactants).
This article describes the factors affecting the efficiency of self-winding and the effect of adsorption on the eco-nomic component of the technology. To solve the problem of adsorption, preventing the large-scale introduction of surfactant, it is proposed to use the technology of microencapsulation of surfactants in a solid shell.
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MAIN FEATURES AND CHARACTERISTICS OF CHEMICAL AND PHYSICAL-CHEMICAL METHODS OF ANALYSIS OF SURFACTANTS

Abstract
One of the most acute and pressing problems of sustainable development in the coming century can be providing the population with quality drinking water. According to estimates of the World Health Organization, the frequency of diseases arising from the use of poor-quality drinking water is the highest. Pollution of the environment by surfactants is a great danger to the entire biosphere. Unlike organic substances, they are not subject to degradation and, in addition to the direct toxic effect on living and plant organisms, tend to accumulate in food chains, which increases their danger to humans.
The flow of surfactants into reservoirs occurs mainly from man-made sources. With the inefficient purification of water, surfactants enter the natural reservoirs, the soil, and along trophic feeding routes reach people. Accumulating in reservoirs, surfactants have a strong toxic effect on the flora and fauna, worsen the organoleptic characteristics of water, prevent the processes of self-purification of water bodies. Even small amounts of surfactants cause abundant foaming, disrupt oxygen exchange in water bodies, and inhibit photosynthesis.
To achieve one hundred percent purification of wastewater from surfactants is almost impossible. In this connection, the search for new and improvement of existing methods of analysis of surface-active substances is very important.
The article presents the main features and characteristics of chemical and physico-chemical methods for the analysis of synthetic surfactants.
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