USE OF SURFACTANTS FOR INTENSIFICATION OF OIL PRODUCTION DURING PRIMARY AND SECONDARY FORMATION PENETRATIO

Аннотация

A complex study of surface-active substance SCA containing Neonol AF 9-12 - oxyethylated monoalkylphenol as a nonionic surfactant has been performed. It is shown that the SCA does not interact with the deposit water, shows demulsifying properties, reduces the interfacial tension to ultralow values, adsorbs slightly on the core. The effects of ionic strength and nature of electrolyte on the surface properties of surfactant have been studied. The compositionofthe punching liquidfor secondary access technologies based onthesurface-active substance SCA-515 and an aqueous solution of potassium chloride has been found. Researches of the designed punching fluid have shown its high inhibitory ability, compatibility with formation fluid and mud filtrate. Industrial (Peschanoozerskoe field) tests have shown high efficiency of surfactants: flow rates increasing, the term reduction of well development and decreaseof skineffect. Key words:drilling fluids,surface-active reagents, surfactants, oil production, perforation fluid. Аннотация: Проведено комплексное исследование поверхностно-активного вещества SCA,содержащего в качестве неионогенного ПАВ Неонол АФ 9-12 - оксиэтилированный моноалкилфенол. Показано, что SCA не взаимодействует с пластовой водой, проявляет деэмульгирующие свойства, снижает межфазное натяжение до сверхнизких значений, слабо адсорбируется на керне. Изучено влияние ионной силы и природы электролита на поверхностные свойства ПАВ. Найден состав перфорационной жидкости для технологий вторичного доступа на основе поверхностно-активного вещества SCA и водного раствора хлорида калия. Исследования разработанной перфорационной жидкости показали ее высокую ингибирующую способность, совместимость с пластовым флюидом и фильтратом бурового раствора. Промышленные (Песчаноозерское месторождение) испытания показали высокую эффективность ПАВ: увеличение дебитов, сокращение сроковосвоения скважини снижениескин-эффекта. Ключевые слова: буровые растворы, поверхностно-активные реагенты, ПАВ, добыча нефти,перфорационная жидкость. Introduction: Analysis ofoil production practices and the results ofscientific studies convincingly shows that the potential productivity of wells is directly related to the quality of work during their completion. In recent years, during the development of oil fields, areas with complex geological and technical conditions have been drilled more and more often, while productive horizons have low reservoir properties and abnormally low reservoir pressures, which predetermines increased requirements for the choice of completion technologies and, in particular, fortheissues ofprimary and secondary penetration ofproductive formations. Themain cause ofdamage (contamination) ofpay zones is successive penetration of water-based process fluids - drilling mud filtrates, cement slurry and perforation fluid. Studies have shown 67 Volume 4, issue 5, 2025 that the permeability of reservoir rocks decreases to the greatest extent under the influence of mud filtrate. The reasons for the decrease in the permeability of formations in the zone of penetration of filtrates ofprocess liquidsare diverseThese include: -swelling ofclay minerals contained inthe formation; -formation of emulsionsduring partial displacement offormation fluid Penetration of filtrates into the formation can occur not only under the influence of the pressure drop "well-formation," but also under the influence of capillary pressure in the case when the walls of pore channels are hydrophilic. Obviously, capillary pressure, by promoting filtrate penetration into the porous medium, prevents its displacement from the pores of the formation during operation, blocking part of the pores and thereby reducing the permeability of the porous medium. In addition, oil-water emulsions may be formed to prevent the movement of formation fluid. Thecapillary pressure value according toLaplace's formulais: РК = 2а≈ cos 0/r, where a-interfacial tension, 0-wetting angle, r-capillary radius. Capillary pressure should be reduced to facilitate removal of penetration products from the bottomholezoneand improveoil filtration conditions. Therefore, to achieve high-quality drilling-in of oil formations, it is necessary to reduce the surface tension at the "solution filtrate - formation fluid" boundary by using surface-active substances (SAS), and to reduce surface wetting with water and to increase surface wetting with hydrocarbons (increase thewetting angle) byusingwater repellents. The most radical means of preventing contamination of the bottomhole formation zone is to use hydrocarbon-based solutions as process fluids when drilling in productive horizons. However, due to their high cost, increased environmental hazard, fire hazard, and a number of other reasons, these solutions have limited application. The use of inverse emulsions in drilling and oilfieldpractice isexpanding. It should be noted that water-based process fluids are most widely used in well completion te