Известия Томского политехнического университета: Инжиниринг георесурсов (Jul 2020)
FORMATION OF A METHODOLOGICAL APPROACH FOR RESEARCH OF SURFACE-ACTIVE SUBSTANCES TO ENHANCED OIL RECOVERY (ON THE EXAMPLE OF DEPOSIT OF THE UDMURT REPUBLIC)
Abstract
The relevance of the research. Currently, most of oil fields of Russia have entered the late stage of development. As there is the depletion of easily recoverable oil reserves, more and more efforts are directed at creating technologies and development methods that allow producing hydrocarbons in difficult conditions. For further development of fields with hard-to-recover reserves, the introduction of new methods for increasing oil recovery and the use of new reagents are required. A significant role in this matter is given to chemical methods, in particular the use of solutions of surfactants. Exposure of aqueous surfactant solutions improves the rheological and filtration characteristics of oil by reducing interfacial tension and increasing wetting ability. in this relation, the task of choosing a surfactant for use in the waterflooding system of reservoirs, as well as the development of methodological approaches for their selection, is of current interest. The main aim of the research is toform a methodological approach to study the surfactants used in the waterflooding system to increase oil recovery. Object: carbonate collectors of Udmurt Republic. Methods: laboratory studies of compositions, device for determining the surface tension of surfactant solutions – stalagmometer «Rubin-02 A», filtration units with simulation of formation conditions of UIP-5VG and AFS-300, centrifuge process. Results. The paper identifies the urgent problem – the process of selecting surfactant technology for effective application in the waterflooding system for achieving the highest oil recovery. The surface-active substances that have found active industrial use in the fields of Russia and beyond are analyzed. The physicochemical and technological properties of Russian-made surfactants were evaluated in accordance with the passport characteristics, the requirements of the Provisions of a subsurface user enterprise, and the suitability of chemicals for further use was determined. The paper considers the methodology and results of determining the coefficient of oil displacement with aqueous surfactant solution on core samples taken from deposits in the Udmurt Republic. An express method for assessing the oil-displacing ability of a surfactant is proposed. It is more economical and energy-efficient in comparison with standard filtration studies. According to the results of filtration tests on the core, it was found that the proposed method is comparable with the studies. In general, the proposed methodology for the choice of surfactant composition is possible for implementation in local regulatory documents of a subsoil user enterprise and for use in order to select the necessary reagent to increase oil recovery.
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