In this paper, the effect of natural trass rock as a pozzolanic mineral additive on the rheological, physicochemical and mechanical properties of class G Portland cement, widely used in oil well drilling and workover operations, was studied. Trass, obtained from the Koroglu deposit in the Lesser Caucasus region of Azerbaijan, was incorporated into the cement system at 5, 10 and 15 wt.% replacement levels. Its chemical and mineralogical properties were determined using X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses. Experimental results show that the addition of trass significantly improves the performance of the mixture by increasing slurry fluidity and reducing the plastic viscosity, while simultaneously increasing stability under dynamic conditions. The rheological stability of the cement slurry was improved by approximately 7-9 % compared to pure cement systems. In addition, the compressive strength increased significantly, indicating improved structural integrity. These effects are mainly attributed to pozzolanic reactions between reactive amorphous silica (SiO₂) and alumina (Al₂O₃) in the trawl and calcium hydroxide formed during cement hydration, and the interaction promotes the formation of additional calcium silicate hydrate (C–S–H), resulting in a denser and finer microstructure. In addition, the modified cement systems demonstrated increased durability, including higher resistance to thermal cycling and aggressive formation fluids such as saline waters and CO₂-rich environments. İn this study use of natural trass can help reduce the carbon footprint associated with traditional cement systems by partially replacing the clinker content.

Keywords: oil well cementing; class G Portland cement; natural trass; rheology; pozzolanic reaction; zonal isolation.

Date submitted: 19.11.2025     Date accepted: 21.04.2026     Date published: 30.07.2026

References

1. Efendiyev, G. M., Moldabayeva, G. Z., Buktukov, N. S., et al. (2024). Comprehensive cementing assessment and risk management system. SOCAR Proceedings, 4, 42-47.
2. Shekarchi, M., Ahmadi, B., Azarhomayun, F., et al. (2023). Natural zeolite as a supplementary cementitious material – A holistic review of main properties and applications. Construction and Building Materials, 409, 133766.
3. Girskas, G., Skripkiūnas, G., Skripkiūnas, G., et al. (2022). Use of natural zeolite and glass powder mixture as partial replacement of portland cement: The effect on hydration, properties and porosity. Materials, 15(12), 4219.
4. Hasanbeigi, A., Price, L., Lin, E. (2012). Emerging energy-efficiency and CO2 emission-reduction technologies for cement and concrete production: A technical review. Renewable and Sustainable Energy Reviews, 16(8), 6220-6238.
5. Abdullaev, A. I., Guliev, I. B., Bagirov, O. E., et al. (2016). Prospects for the application of new technologies in cementing oil and gas wells. Oil and Gas Territory, 4, 26-31.
6. Costafreda, J. L., Martín, D. A., Presa, L., Parra, J. L. (2021). Effects of a natural mordenite as pozzolan material in the evolution of mortar settings. Materials, 14(18), 5343.
7. Salamanova, М. Sh. (2022). Study of cement properties for plugging oil wells. Herald of Dagestan State Technical University. Technical Sciences, 49(1), 149-155.
8. Efendiyev, G. M., Moldabayeva, G. Zh., Tuzelbayeva, Sh. R., et al. (2025). Enhancing cement mortar performance for construction and oil well applications using fiber reinforcement. ES Materials and Manufacturing, 30, 1771.
9. Mejdi, M., Wilson, W., Saillio, M., et al. (2019). Investigating the pozzolanic reaction of post-consumption glass powder and the role of portlandite in the formation of sodium-rich C-S-H. Cement and Concrete Research, 123, 105790.
10. Kriptavicius, D., Girkas, G. (2021). Influence of natural zeolite on Portland cement hydration processes and properties of hardened cement paste. Ceramics-Silikáty, 65(3), 247-254.
11. Agzamov, F. A., Babkov, V. V., Karimov, I. N. (2011). On the required expansion value of cementing materials. Oil and Gas Territory, 8, 14-15.
12. Guliyev, I. R. (2015). Early detection of complications during drilling of oil and gas wells and improvement of the technology of combating them. PhD Thesis. Baku.
13. Shamilov, V. M., Abdullayev, A. I., Guliyev, I. B., Safarov, Y. O. (2024). Influence of nanostructured cement slurry on the quality of well cementing. Oil Industry, 3, 52-55.
14. Duarte, D. (2015). Cement slurry with silica flour and calcined clay for cementation of oil-wells subject to high temperature. https://www.researchgate.net/publication/312376793
15. Perraki, T., Glikeriya, K., Kontpleon, F. (2003). The effect of natural zeolites on the early hydration of Portland cement. Microporous and Mesoporous Materials, 7, 205-212.
16. Singh, R., Sharma, R., Ranga Rao, G. (2023). Magnesium bromide as a novel high density packing fluid for oilfield applications. Energy Resources and Technology, 145, 501-513.
17. Ramezanyanpur, A. A., Sarvari, A., Ahmadi, B. (2012). Use of natural zeolite to produce self-consolidating concrete with low portland cement content and high durability. Journal of Materials in Civil Engineering, 25(5), 589–596.
18. Kabdushev, A. A., Kembayev, A. R., Bimbetova, G. Zh., et al. (2025). Development of the composition of lightweight cement slurry using microspheres and microsilica. SOCAR Proceedings, 2, 40-47.
19. Loginova, M. E., Chetvertneva, I. A., Kolchina, G. Yu., et al. (2025). Experimental studies of the rheological properties of polymer compositions for well drilling and oil production. SOCAR Proceedings, 3, 31-38.
20. Ismayilov, G. G., Veliyev, R. H., Gulubayli, A. P. (2024). About loss of structural stability during movement of drilling fluids. SOCAR Proceedings, 2, 90-94.
21. Kassanova, A. G., Tulegenova, O. Sh., Koishina, A. I., et al. (2026). Assessment of environmental safety of harmful substances in drilling waste in Kazakhstan. SOCAR Proceedings, 1, 150-157.
22. (2006). Explanatory dictionary of geological terms. Baku.
23. (1973). Geological dictionary. Moscow.
24. Kashkai, M. A., Semenova, A. I., Zaitseva, L. V., et al. (2005). Mineral resources of Azerbaijan. Baku.
25. M3600 Voscometr. https://gic.com/M3600.php

Cementing of casing strings is one of the most critical stages in oil and gas well construction, as it determines the effectiveness of zonal isolation, operational safety, and the long-term integrity of the wellbore. The quality of cementing largely depends on the proper selection of cement slurry composition and the control of its key technological parameters, including density, rheological characteristics, sedimentation stability, and water separation. Inadequate optimization of these properties can lead to channeling, gas migration, poor bonding, and premature loss of well integrity. Traditional weighting materials such as hematite and barite are widely used to increase the density of cement slurries for high-pressure formations. However, their application often causes a deterioration of rheological properties, increased viscosity, enhanced water separation, and, in some cases, a reduction in the mechanical strength of the hardened cement stone. These effects may negatively influence slurry placement efficiency and the quality of the cement sheath. One of the most promising approaches to overcoming these limitations is the incorporation of modern superplasticizers into cement systems. Superplasticizers significantly improve slurry flowability while reducing the water-to-cement ratio, which contributes to higher density, lower porosity, improved sedimentation stability, and enhanced compressive strength of the hardened cement. In addition, they reduce free water content and improve the homogeneity of the cement matrix. Experimental investigations demonstrate that the combined use of weighting agents and advanced superplasticizers provides an optimal balance between density, rheological performance, and durability of the cement stone. The obtained results confirm the effectiveness of this approach for improving cementing quality and ensuring reliable zonal isolation under complex geological and technological conditions encountered in modern oil and gas wells.

Keywords: well cementing; cement slurry; slurry density; superplasticizers; water–cement ratio; sedimentation stability.

Date submitted: 10.03.2026     Date accepted: 17.06.2026     Date published: 30.07.2026

References

1. (1991). API Specification 10A. Cementing Materials and Equipment, 21st Ed. Washington, DC, USA: American Petroleum Institute.
2. Nelson, E. B. (1990). Well cementing. TX, USA: Schlumberger Educational Services, Sugar Land.
3. Lea, F. M. (1998). The chemistry of cement and concrete. 4th Ed. London, UK: Edward Arnold.
4. Hewlett, P. C. (Ed.). (2003). Lea’s chemistry of cement and concrete. 5th Ed. Amsterdam, Netherlands: Elsevier.
5. Florea, M. V., Yavorsky, P. M. (1999). Rheology and thickening time control of class G oil well cement slurries. SPE Journal of Petroleum Technology.
6. Siddique, R. (2008). Properties of concrete containing cementitious materials. Berlin, Germany: Springer.
7. Felemban, S. A. (2010). Effect of superplasticizers on rheological and mechanical properties of cement slurries. Construction and Building Materials, 24(7), 1098–1103.
8. Radonjic, M., Klaić, Z. B. (2007). Influence of superplasticizers on properties of cement-based materials. Cement and Concrete Composites, 29(2), 94–102.
9. Caré, S., Martys, N. (2001). A physical model for sedimentation and stability of cement slurries. Cement and Concrete Research, 31(6), 817–825.
10. Shamsabadi, A. A., Alizadeh, A. (2010). Effect of barite and hematite on rheology and strength of oilwell cement slurries. Journal of Petroleum Science and Engineering, 72(1–2), 106–112.
11. Li, G. (2012). Effect of nano-silica on rheological and mechanical properties of cement slurries. Journal of Materials in Civil Engineering, 24(9), 1187–1194.
12. Neupane, K. R. (2005). Study of additives for density and stability control of oil well cement slurries. In: SPE International Cementing Conference.
13. Chang, I., Lee, J. (2004). Mechanisms of superplasticizer action in cement slurries. Cement and Concrete Research, 34(12), 2203–2211.
14. Topçu, I. B., Uygunoğlu, T. (2010). Effect of barite particle size on oil well cement slurry properties. Journal of Petroleum Science and Engineering, 76(3–4), 167–172.
15. (2020). ASTM C150/C150M-20. Standard specification for portland cement. West Conshohocken, PA, USA: ASTM International.
16. (2018). ASTM C114-18. Standard test methods for chemical analysis of hydraulic cement. West Conshohocken, PA, USA: ASTM International.
17. (2014). ASTM D854-14. Standard test methods for specific gravity of soil solids by water pycnometer. West Conshohocken, PA, USA: ASTM International.
18. (2018). ASTM C191-18. Standard test methods for time of setting of hydraulic cement by vicat needle. West Conshohocken, PA, USA: ASTM International.
19. Al-Fattah, S. M. (2008). Rheological properties of cement slurries containing dispersants. Petroleum Science and Technology, 26(11), 1231–1242.
20. Yang, R. (2016). Evaluation of waste-derived additives for oil well cementing applications. Journal of Cleaner Production, 112, 2139–2147.
21. Bulatov, A. I., Savin, V. V. (1996). Cementing of oil and gas wells. Moscow: Nedra.
22. Kryzhanovsky, E. I. (2004). Well cementing technology. Moscow: Moscow State Mining University.
23. Aliyev, A. A. (2008). Well cementing in complicated conditions. Baku: Elm.
24. Suleymanov, E. M. (2015). Improvement of cement slurries for offshore wells. Oil Industry, 8, 45–52.
25. Gurbanov, R. S. (2017). Effect of additives on the stability of cement slurries. Oil Economy of Azerbaijan.
26. Мyslyuk, M. A. (2019). Determination of rheological properties of drilling fluids by rotational viscometry data. SOCAR Proceedings, 4, 4-12.
27. Akhmedov, T. K. (2012). Drilling fluids and well cementing. Baku.
28. Ivanov, P. A. (2003). Permeability of cement stone in wells. Oil Industry, 4, 55–59.
29. Petrov, N. N. (2001). Physicochemical mechanics of cement systems. Moscow.
30. Kadyrov, R. R. (2018). Sedimentation stability of cement slurries. Drilling and Oil, 5, 22–28.
31. Plank, J., Hirsch, C. (2021). Impact of zeta potential of early cement hydration phases on superplasticizer adsorption. Cement and Concrete Research, 37(4), 537-542.
32. Efendiyev, G. M., Moldabayeva, G. Zh., Tuzelbayeva, S. R., et al. (2025). Enhancing cement mortar performance for construction and oil well applications using fiber reinforcement. ES Materials and Manufacturing, 30, 1771.
33. Li, G. (2022). Recent advances in cement slurry additives for oil well cementing. Journal of Petroleum Science and Engineering.
34. Efendiyev, G. M., Moldabayeva, G. Z., Buktukov, N. S., Kuliyev, M. Y. (2024). Comprehensive cementing quality assessment and risk management system. SOCAR Proceedings, 4, 42-47.
35. Zhang, Y. (2023). Effect of nano-materials on rheology and stability of cement slurries. Construction and Building Materials.
36. Deryaev, A. R., Geldyeva, Ch., Saduakassov, D. S. (2026). Development of foam drilling fluids for drilling and well killing under conditions of abnormally low formation pressure. SOCAR Proceedings, 2, 12-26.
37. Kabdushev, A. A., Kembayev, A. R., Bimbetova, G. Zh., et al. (2025). Development of the composition of lightweight cement slurry using microspheres and microsilica. SOCAR Proceedings, 2, 40–47.
38. Stavychnyi, Ye. M., Femiak, Ya. M., Vytyaz, O. Yu., et al. (2025). Improving the reliability of oil and gas well cementing with the applying of composite plugging systems. SOCAR Proceedings, 3, 59–69.
39. Asadova, G. Sh. (2026). Application of nanostructured systems in the isolation of lost circulation zones. SOCAR Proceedings, SI1, 32–38.

The reliability and sealing performance of casing strings is one of the most significant scientific and engineering difficulties associated with drilling oil and gas wells. Important parts that guarantee annular space sealing and safe support for casing strings inside the well are wedge-type casing hangers. The advancement of the oil and gas sector has coincided with the development of wedge-type casing hangers. Many changes have been implemented in recent years to enhance their operational safety, performance, and dependability. Nevertheless, increasing the dependability and sealing effectiveness of wedge-type casing hangers continues to be a significant problem for the oil and gas sector as well as producers of oilfield equipment, despite intensive research and engineering efforts. The operating principle of wedge-type casing hangers is based on converting an axial force into a clamping force that securely holds the casing or another structural element in place. Although the design is relatively simple, the system is susceptible to wear, reduced clamping force, and other failure mechanisms, making a comprehensive approach to reliability assessment essential. Achieving high reliability of wedge-type casing hangers largely depends on several key parameters, including the wedge angle, the coefficient of friction, and the applied loads. Under real operating conditions, these parameters cannot be determined with complete accuracy. Therefore, selecting the optimal design and operating conditions requires a method capable of handling uncertainty, such as fuzzy logic. Based on this, the present study is aimed at determining the optimal operating parameters of wedge-type casing hangers using the principles of fuzzy logic. 

Keywords: wedge-type casing hanger; wellhead; fuzzy logic theory; wedge angle; coefficient of friction; reliability; casing string.

Date submitted: 10.05.2026     Date accepted: 27.07.2026      Date published: 31.07.2026

References

1. Shishlyannikov, D. I., Nikolaev, A. V., Ostrovsky, V. G. (2018). Fundamentals of operation and repair of drilling and oil and gas production equipment. Perm: Publishing House Center of the Perm National Research Polytechnic University.
2. Yanushonok, A. N. (2014). Fundamentals of oil and gas business. Novopolotsk: Polotsk State University.
3. Bulatov, A. I., Proselkov, Yu. M., Shamanov, S. A. (2003). Technique and technolo-gy of drilling oil and gas wells. Moscow: Nedra.
4. Calonne strapping (column head) OCC 1-21, OCC 1-35. https://aznefteximmash.narod.ru
5. (1987). AZINMASH Research and Development Report "Research and improvement of suspension units for lifting systems of drilling rigs". Baku: AZINMASH.
6. Gulamov, R. B. (2021). Modernization of the OKK2M-35-146 column head. Kazakh National Technical University named after K.I.Satpayev.
7. Smirnov, A. V., Petrov, D. N. (2020). Technologies of operation of oil and gas wells: a textbook. St. Petersburg: Polytech Press.
8. Karazhanova, M. K., Moganlu, R. G., Piriverdiev, I. A. (2023). Assessment of relia-bility characteristics of oilfield equipment and decision-making in conditions of uncertainty. Yessenov Science Journal, 45(2), 165-170.
9. Agammadova, S. A. (2019). Factors influencing the rate of growth of destruction and damage to the gas pipeline from corrosion and methods of their elimination. SRI “Geotechno-logical Problems of Oil, Gas and Chemistry”, XIX volume, 234-242.
10. Babaev, S. G., Kershenbaum, V. Ya., Gabibov, I. A. (2018). The evolution of the quality of tribo-conjugations of oil and gas equipment. Moscow-Baku: NING.
11. Abbaspoor-Zanjani, S., Antonini, C., Gatti, T., Wang, M. (2026). Anti-slip material-based strategies and approaches. Advanced Materials Technologies, 10, e01936.
12. Protasov, V. N., Sultanov, B. Z., Krivenkov, S. V. (2004). Operation of equipment for drilling wells and oil and gas production. Moscow: Nedra - Businesscenter LLC.
13. Habibov, I., Asgarov, E., Eyvazova, Z. (2026). Improvement of casing head wedge suspension design. EUREKA: Physics and Engineering, 3, 95-103.
14. Gabibov, I. A., Askerov, E. A., Eyvazova, Z. E. (2025). Evaluation of risks and reli-ability of wedge suspension mechanisms in wellhead assemblies. In: 7th Eurasian Conference “Risk-oriented Design and Operation of Infrastructure Systems: Sustainability Paradigm”, Ba-ku, 21-23 October.
15. Altunin, A. E., Semukhin, M. V. (2002). Models and algorithms of decision-making in fuzzy conditions. Tyumen: Publishing House of Tyumen State University.
16. Lazim, A. (2013). Fuzzy multi criteria decision making and its applications: A brief review of category. In: 9th International Conference on Cognitive Science. Procedia - Social and Behavioral Sciences, 97, 131–136.
17. (2025). DesignModeler User's Guide. ANSYS, Inc. http://www.ansys.com
18. Dzhanakhmedov, A. Kh., Dyshin, O. A., Shahnazarov, M. A. (2024). The study of the stress-strain state of the downhole packer's jaw teeth based on the initial functions method. SOCAR Proceedings, 3, 82-91.
19. Efendiyev, G. M., Moldabayeva, G. Z., Buktukov, N. S., Kuliyev, M. Y. (2024). Comprehensive cementing quality assessment and risk management system. SOCAR Proceed-ings, 4, 42-47.
20. (1997). Instructions for calculating casing strings for oil and gas wells. Moscow: AOOT "VNIIT–Neft".
21. Askerov, E. A. (2025). Investigation of designs of wedge suspensions of a column head. In: Proceedings of the II All-Russian Scientific Conference with International Participation "TECHNOSPHERE", 16-17 September, KubSTU, Krasnodar.
22. Golosovsky, M. S., Bogomolov, A. V., Terebov, D. S., Yevtushenko, E. V. (2018). An algorithm for configuring a Mamdani-type fuzzy inference system. Bulletin of SUSU. The series "Mathematics. Mechanics. Physics", 10(3), 19-29.
23. Pavlova, K. A., Bereza, N. V., Bereza, A. N., Beglyarov, V. V. (2018). Develop-ment of an information system for determining the costs of an online store based on the Mamdanii algorithm. Bulletin of the Baltic Federal University named after I. Kant. Series: Physi-co-Mathematical and Technical Sciences, 2, 26-38.
24. Dyshin, O. A., Bakirova, I. R., Feyziyeva, G. E. (2024). Innovative methodology for predicting pipe thickness loss based on electromagnetic flaw detection results. SOCAR Pro-ceedings, 1, 132-137.
25. Shalamov, A. N., Kudryashov, B. A., Rakovschik, T. M. (2016). Processing of re-sults and evaluation of measurement accuracy during multiple observations. Moscow: MADI.

A new experimental finding regarding the violation of Darcy's law during the flow of liquids in a microcrack with an opening less than its critical value h<h_cr, i.e., the manifestation of the "microcrack-fluid" effect is observed, which is the reason for the violation of Darcy's law. It has been revealed that when liquid moves in fractured and low-permeability media with an opening of h<h_cr, an additional force arises due to the "microcrack-fluid" effect, which prevents the movement of liquid and this is the reason for the low oil recovery coefficient. The effect in the “microcrack-fluid” system is the reason for changes in the mechanical properties of fluids in microcracks and equivalent ultra-low-permeable porous media. It was revealed that when a one-parameter viscous fluid flows through a crack with an opening h<h_cr, it becomes a two-parameter fluid, i.e. it behaves as an anomalous fluid. When the fluid flows through a crack with an opening h≥h_cr, it restores one-parameter properties. The anomalous behavior is accompanied by an increase in the rheological constants of the model. Based on the developed methodological guidelines, rheological parameters of filtration systems and crack opening under reservoir conditions are determined. According to the research data, the proposed technique makes it possible to estimate the effective crack opening and the corresponding permeability of the porous medium of the bottomhole zone with sufficient accuracy for practice under steady-state well conditions without interrupting well operation. Therefore, to attract residual oil to the well faces, it is necessary to develop measures that allow deposits to be transferred from the h<h_cr state to the h≥hcr state and ensure well flow.

Keywords: microcrack opening; Newtonian fluid; structural viscosity; "microcrack- fluid" effect.

Date submitted: 28.01.2026     Date accepted: 12.05.2026     Date published: 30.07.2026

References

1. Ermolaev, A. I., Efimov, S. I., Pyatibratov, P. V., et al. (2023). Assessment of the maximum bottom-hole pressure, which excludes the destruction of the bottom-hole zone of the formation, based on geomechanical core studies. SOCAR Proceedings, SI1, 61-68.
2. Zangl, G., Hannerer, J. (2003). Data mining: applications in the petroleum industry. Katy, TX: Round Oak Publishing. Hand, D., Manilla, H, Smyth, P. (2001) Principles of data mining. USA: MIT-Press.
3. Vishnyakov, V. V., Suleimanov, B. A., Salmanov, A. V., Zeynalov, E. B. (2019). Primer on enhanced oil recovery. Gulf Professional Publishing.
4. Suleimanov, B. A., Guseynova, N. I., Rzayeva, S. C., Tulesheva, G. D. (2017). Experience of acidizing injection wells for enhanced oil recovery at the Zhetybai field (Kazakhstan). SPE-189028-MS. In: SPE Annual Caspian Technical Conference and Exhibition, Baku, Azerbaijan, 1-3 November.
5. Suleimanov, B. A., Rzayeva, S. C., Keldibayeva, S. S. (2020). A new microbial enhanced oil recovery (MEOR) method for oil formations containing highly mineralized water. Petroleum Science and Technology, 38(23), 999-1006.
6. Bissembayeva, K. T., Mamalov, E. N., Hadiyeva, A. S., et al. (2024). An enhanced oil recovery technology applicable to Kazakhstan deposits with highly viscous oils. SOCAR Proceedings, 1, 107-111.
7. Suleimanov, B. A., Ibragimov, H. M., Hajiyev, A. A., et al. (2024). Method for cleaning the bottom hole formation zone. Eurasian Patent EA046507.
8. Nasybullin, A. V., Persova, M. G., Lutfullin, A. A. (2024). Forecasting the efficiency of waterflooding, thermal and chemical enhanced oil recovery methods in Bobrikovian reservoirs. SOCAR Proceedings, 2, 30-40.
9. Suleimanov, B. A., Abbasov, H. F., Aliyev, R. Y., et al. (2025). Selection of proxy modelling methods for streamline simulation to waterflooding management process in oil reservoirs. SOCAR Proceedings, 2, 55-59.
10. Zeltser, P. S. (2012). Development of gel-forming compositions based on polymer-colloidal complexes of water-soluble polymers with aluminum polyhydroxochloride sols for isolation of water flows in oil-producing wells. PhD Thesis. Volgograd: VolgSTU.
11. Nasybullin, A. V. (2024). Forecasting the efficiency of waterflooding, thermal and thermoactive polymer compositions. SOCAR Proceedings, 3, 17–31.
12. Loginova, M. E., Chetvertneva, I. A., Kolchina, G. Yu., et al. (2025). Experimental studies of the rheological properties of polymer compositions for well drilling and oil production. SOCAR Proceedings, 3, 31-38.
13. Gafarov, Sh. A. (2003). Anomalously viscous oils and their effect on the filtration structure of the pore. In: Increased oil recovery. Development of hard-to-recover oil reserves. Proceedings of the 12th European Symposium "Enhanced Oil Recovery", Kazan.
14. Manyrin, V. N., Shvetsov, I. A. (2002). Physicochemical methods for enhancing oil recovery during flooding. Samara: Samara Printing House.
15. Research and Production Firm Nitpo, LLC. (2016). In: 11th International Scientific and Practical Conference, Sochi, Krasnodar Region.
16. Modern technologies for well workover and enhanced oil recovery. Development prospects. (2012, May 21-26). In: 7th International Scientific and Practical Conference, Gelendzhik, Krasnodar.
17. Suleimanov, B. A., Ibrahimov, Kh. M., Aga-Zade, O. D., Shafiyev, T. X. (2019). Composition for acid treatment of the wellbore zone of the reservoir. Patent of The Republic of Azerbaijan İ 20190092.
18. Suleimanov, B. A., Jamalbayov, M. A., Ibrahimov, Kh. M. (2023). Algorithm for determining the optimal coordinates of the water shutoff composition in the bottom hole zone. ANAS Transactios, Earth Sciences, Special Issue, 27-30.
19. Karpov, A. A. (2009). Improving the efficiency of acid treatments of highly watered wells in fractured-porous carbonate reservoirs. PhD Thesis. Ufa.
20. Kazimov, F. K., Rzayeva, S. J., Mammadov, K. A. (2026). Development of a new method for treating the near-wellbore zone of water-flooded wells. SOCAR Proceedings, SI1, 69-74.
21. Suleimanov, B. А., Abdullayev, V. D., Таpdigov, Sh. Z., et al. (2022). Method of water shut-off to well. Eurasian Patent EA 043725.
22. Bulgakova, G. T., Bayzagitova, A. V., Sharifullin, A. R. (2009). Model of matrix acid treatment of carbonates: the effect of sediment on the dissolution process. Bulletin of Ufa State Atomic Energy University, 13(2(35)), 256-264.
23. Mordvinov, V. A. (2011). Mechanism of the effect of hydrochloric acid solutions on a carbonate reservoir. Oil Industry, 1, 44-46.
24. Kharisov, R. Ya., Sharifullin, A. R., Telin, A. G., Zagurenko, A. G. (2007). Factors affecting the efficiency of acid stimulation of wells in carbonate reservoirs. Scientific and Technical Bulletin of OAO NK Rosneft, 1, 18-24.
25. Ilyasov, S., Mantrov, A., Konchenko, A., et al. (2010). Chemical diverters to increase well productivity and reduce water cut. Oil and Gas of Russia, 5, 62-64.
26. Economides, M. D., Nolte, K. G. (1992). Impact on oil and gas reservoirs. Part 2. Translated from English. A. I. Bulatov (Ed.). Krasnodar.
27. Shipilov, A. I., Krutikhin, E. V., Kudrevatykh, N. V., Mikov, A. I. (2012). New acid compositions for selective treatment of carbonate porous-fractured reservoirs. Oil Industry, 2, 80-83.
28. Rudobashta, S. P., Kartashov, E. M. (1993). Diffusion in chemical-technological processes. Moscow: Chemistry.
29. Kuryashov, D. A. (2008). Acid composition for targeted treatment of the bottom hole formation zone. In: IV All-Russian Scientific and Practical Conference "Oilfield Chemistry", Moscow. 
30. Gadzhiev, A. A. (2010). Improving the efficiency of vibration action on the oil reservoir and the bottom-hole zone of the well. PhD Thesis. Baku.
31. Qi, Ch., Guzev, M. A., Poplygin, V. V., Kunitskikh, A. A. (2022). Forecasting the permeability of the bottomhole formation zone under wave action. Notes of the Mining Institute, 258, 998-1007.
32. Zhang, L., Wang, X., Wang, J., Yang, Z. (2021). Mechanical characteristics and pore evolution of red sandstone under ultrasonic high-frequency vibration. AIP Advances, 11(51), 055202.
33. Cardoni, A., Harkness, P., Lucas, M. (2010). Ultrasonic rock sampling using longitudinal-torsional vibrations. Ultrasonics, 50(4-5), 447-452.
34. Fernando, P. K. S. C., Meng, Zh., Pei, Z. (2018). Rotary ultrasonic machining of rocks: An experimental investigation. Advances in Mechanical Engineering, 10, 3.
35. Wiercigroch, M., Wojewoda, J., Krivtsov, A. M. (2005). Dynamics of ultrasonic percussive drilling of hard rocks. Journal of Sound and Vibration, 280(3-5), 739-757.
36. Li, N., Zhang, P., Chen, Y., Swoboda, G. (2003). Fatigue properties of cracked, saturated and frozen sandstone samples under cyclic loading. International Journal of Rock Mechanics and Mining Sciences, 40(1), 145-150.
37. Fernando, P.K.S.C., Pei, Z. J., Meng, Zh. (20200. Mechanistic cutting force model for rotary ultrasonic machining of rocks. International Journal of Advanced Manufacturing Technology, 109(1-2), 109-128.
38. Da-Jun, Z., Peng, Y. (2015). Research on the influence rule of ultrasonic vibration time on granite damage. Journal of Mining Science, 54(5), 751-762.
39. Li, S. Q., Yan, T., Li, W., Bi, F. Q. (2015). Modeling of vibration response of rock by harmonic impact. Journal of Natural Gas Science and Engineering, 23, 90-96.
40. Mammadova, M. A. (2022). Investigation of fluid dynamics in microfracture channels. Eastern-European Journal of Enterprise Technologies, 4(7(118), 42–50.
41. Mammadova, M. (2024). Development of a new method for solving problems of compressing various liquids with the manifestation of the “microcrack-fluid” effect. Eureka: Physics and Engineering, 2, 34-44.

A separate injection scheme for nanofluid and brine solutions with subsequent flow mixing prior to entering an oil-saturated porous sample was developed and experimentally implemented. A regime-dependent interfacial concept, Regime-Dependent Interfacial Control (RDIC), is proposed to describe residual oil mobilization mechanisms at low and ultra-low capillary numbers (Ca ≤ 10⁻⁶), which are characteristic of mature carbonate reservoirs. It is shown that under ultra-low Ca conditions, the contribution of viscous forces becomes significantly reduced, while wettability alteration and structural (disjoining) pressure arising in thin aqueous films due to intermolecular and electrostatic interactions become dominant mechanisms controlling oil displacement. Under these conditions, the classical interfacial tension (IFT)-oriented paradigm alone cannot fully explain the observed increase in oil recovery. An energetic model is proposed that accounts for the combined effects of capillary pressure, adhesion work, contact-angle alteration, and structural pressure on residual oil displacement. To quantitatively characterize regime transitions, two dimensionless criteria are introduced: the RDIC parameter Ψ, describing the balance between hydrodynamic and interfacial effects, and the adsorption-induced wettability criterion Ω, reflecting the contribution of surface adsorption to wettability alteration. It is shown that nanofluids, fluorinated polymers, and citrate-based N-alkylamide surfactants, despite their different chemical nature, exhibit similar displacement mechanisms associated with reduced oil adhesion, stabilization of thin aqueous films, and the transition of the rock surface toward more water-wet conditions. The proposed RDIC concept can be used for mechanistic interpretation of physicochemical enhanced oil recovery processes and for optimization of displacement-system formulations in carbonate and heterogeneous reservoirs under ultra-low capillary-number conditions.

Keywords: enhanced oil recovery; carbonate reservoirs; ultra-low capillary number; wettability alteration; disjoining pressure; nanofluids; polymer flooding; surfactant flooding; thin liquid films; RDIC framework. 

Date submitted: 23.02.2026     Date accepted: 22.05.2026     Date published: 31.07.2026

References

1. Bear, J. (1972). Dynamics of fluids in porous media. Elsevier.
2. Adamson, A. W., Gast, A. P. (1997). Physical chemistry of surfaces. Wiley.
3. Lake, L. W. (1989). Enhanced oil recovery. Prentice Hall.
4. Morrow, N. R. (1990). Wettability and its effect on oil recovery. SPE Journal of Petroleum Technology, 42(12), 1476–1484.
5. Firoozabadi, A. (1999). Thermodynamics of hydrocarbon reservoirs. McGraw-Hill.
6. Danesh, A. (1998). PVT and phase behaviour of petroleum reservoir fluids. Elsevier.
7. Tweheyo, M. T., Holt, T., Torsæter, O. (1999). An experimental study of the relationship between wettability and oil production characteristics. Journal of Petroleum Science and Engineering, 24, 179–188.
8. Hendraningrat, L., Li, S., Torsæter, O. (2013). A coreflood investigation of nanofluid enhanced oil recovery. Journal of Petroleum Science and Engineering, 111, 128–138.
9. Hendraningrat, L., Torsæter, O. (2015). Metal oxide-based nanoparticles: potential to enhance oil recovery. Applied Nanoscience, 5, 181–199.
10. Sheng, J. J. (2011). Modern chemical enhanced oil recovery. Elsevier.
11. Derjaguin, B. V. (1989). Theory of stability of colloids and thin films. Springer US.
12. Derjaguin, B. V., Landau, L. D. (1993). Stability of strongly charged lyophobic sols. Progress in Surface Science, 43, 30–59.
13. Lan, Y., Caciagli, A., Guidetti, G., et al. (2018). Unexpected stability of aqueous dispersions of raspberry-like colloids. Nature Communications, 9, 3614.
14. Israelachvili, J. N. (2011). Intermolecular and surface forces. Academic Press.
15. Tong, Q., Fan, Z., Liu, Q., et al. (2023). Research progress in nanofluid-enhanced oil recovery technology and mechanism. Molecules, 28, 7478.
16. Hou, J., Du, J., Sui, H., Sun, L. (2022). Application of nanofluids in enhanced oil recovery. Frontiers of Chemical Science and Engineering, 16, 1165–1197.
17. Scott, A. J., Romero-Zerón, L., Penlidis, A. (2020). Evaluation of polymeric materials for chemical EOR. Processes, 8, 361.
18. Firozjaii, A. M., Saghafi, H. R. (2020). Chemical enhanced oil recovery using polymer flooding. Petroleum, 6, 115–122.
19. Sakthivel, S., AlDhawi, Z. A., Abdulhamid, M. A. (2023). Citric acid-based N-alkyl amides for enhanced oil recovery in carbonate reservoir. Fuel, 338, 127362.
20. Li, X., Zhang, Y., Wang, Q. (2023). Advanced polymer flooding techniques for heterogeneous reservoirs. Journal of Petroleum Science and Engineering, 226, 110780.
21. Kumar, S., Singh, R., Verma, P. (2024). Fluorinated polymers and nanofluid synergy for tertiary oil recovery. Fuel, 385, 128754.
22. Chen, L., Zhao, J., Li, H. (20236). Citric acid-based surfactants in carbonate reservoirs. Chemical Engineering Journal, 459, 141740.
23. Ahmed, T., Al-Mutairi, S. (2024). Nanoparticle-assisted EOR: Optimization of size, concentration, and injection rate. Energy & Fuels, 38, 1520–1535.
24. Wang, Y., Liu, S., Geng, X. (2023). Rheology and adsorption behavior of HPAM-fluorinated copolymers under high salinity and temperature. Journal of Applied Polymer Science, 140, 52315.
25. Zhang, H., Li, X., Feng, Y. (2025). Enhanced oil recovery in carbonate formations using bio-inspired surfactants. Fuel Processing Technology, 251, 108782.
26. Ali, R., Khan, A., Haider, Z. (2024). Polymer-nanoparticle hybrid systems: Insights into adsorption, mobility control, and EOR performance. Journal of Molecular Liquids, 383, 122452.
27. Aliyev, E. N., Asadov, M. M., Bogopolskiy, V. O. (2025). Application of new ejector to recover residual oil from depleted formations. SOCAR Proceedings, 4, 3-11.
28. Asadov, M. M., Aliyev, E. N., Salimli, A. M. (2025). Janus interfacial catalysts and nanoparticles for enhanced oil recovery: synthesis, mechanisms, and novel conceptual approaches. Scientific Proceedings SRI GPOGC, 25, 169-175.
29. Shamilov, V. M., Babayev, E. R., Mammadova, P. Sh, et al. (2023). Some aspects of the use of carbon nanotubes for enhanced oil recovery. SOCAR Proceedings, SI1, 115-120.
30. Suleimanov, B. A., Rzayeva. S. J., Akbarova. A. F., Akhmedova. U. T. (2025). Novel strategy for scale prevention in water injection systems. SPE-230450-MS. In: SPE Annual Caspian Technical Conference and Exhibition, Baku, Azerbaijan, November.
31. Kazimov, F. K., Rzayeva, S. J., Mammadov, K. A. (2026). Development of a new method for treating the near-wellbore zone of water-flooded wells. SOCAR Proceedings, SI1, 69-74.
32. Asadov, M. M., Aliyev, E. N., Salimli, A. M. (2026). Intensification of oil field development by chemical methods and the kinetics of paraffin deposition from oil. Azerbaijan Oil Industry, 3, 33-45.
33. Abdullayev, V. J., Huseynov, M. A. (2026). Assessment of enhanced oil recovery methods based on hydrodynamic model. SOCAR Proceedings, 1, 54-64.
34. Hadiyeva, A. S., Mamalov, Y. N., Bissembayeva, K. T., et al. (2026). Methodology for determining the optimal concentration of an alkali solution for enhanced oil recovery. SOCAR Proceedings, 1, 65-69.
35. Skorobogatov, A. A., Pshenin, V. V., Duchnevich, L. D. (2025). Review of multiphase oil-water flow characteristics in horizontal and inclined pipelines. SOCAR Proceedings, 4, 81-98.
36. Soltanbekova, K. A., Ramazanova, G. I., Eremin, N. A., et al. (2024). Prospects and current state of chemical EOR methods applied in Kazakhstan. SOCAR Proceedings, 2, 71-79.
37. Asadov, M. M., Aliyev, E. N., Aliyeva, F. B. (2026). Experimental-modeling study of residual oil recovery from waterflooded reservoirs using enhanced alkaline-foam compositions. Processes Petrochemistry and Oil Refining, 27(3), 1035-1042.

The article is devoted to improving the chemical enhanced oil recovery method through the development of a new composition based on a synergistic effect, aimed at increasing the efficiency of oil displacement from the reservoir. The composition was prepared using reservoir water, an EC 9660A grade dispersant, and diesel-alkaline waste, a residual product of the oil refining industry, as the main components. Laboratory studies have shown that the composition significantly reduces the interfacial tension at the oil interface, increases the hydrophilicity of the rock surface, and decreases capillary blockage. This synergistic effect significantly improves oil mobility. The dispersant prevents the precipitation of diesel-alkaline waste in formation water and maintains system stability, which broadens the applicability of the composition in low-permeability reservoirs. The results of laboratory-experimental studies showed that the application of the new composition increased the final oil displacement coefficient by 32.0% compared to reservoir water. For comparison, the increase for the diesel-alkaline waste solution in reservoir water was 17.5%, while for the dispersant solution it was 26.9%. In a water-flooded porous medium containing residual oil, the optimal size of the sluq formed by the composition was determined to be 12% of the pore volume, resulting in an additional 28.7% increase in the oil displacement coefficient. In the displacement process initiated from the beginning, the water-free oil displacement coefficient increased by 20.7%, while the final displacement coefficient increased by 37.6%. This shows that in all cases, the use of the composition is more effective. The use of the composition improves waste management, reduces component consumption, and ensures production stability, making it promising for industrial application.

Keywords: diesel-alkali waste; dispersant; surfactant; composition; interfacial tension; wetting (contact) angle; reservoir model; porous medium; displacement coefficient; slug; synergistic effect.

Date submitted: 16.01.2026     Date accepted: 06.05.2026     Date published: 31.07.2026

References

1. Brandt, A. R. (2011). Oil depletion and the energy efficiency of oil production: the case of California. Sustainability, 3(10), 1833-1854.
2. Li, Z., Alharthi, S. (2024). Oil revenue and production cost disconnect and its impact on the environment: Economic globalization in Asia-Pacific economic cooperation countries. Geoscience Frontiers, 15(3), 101772-101789.
3. Höök, M., Davidsson, S., Johansson, S., et.al. (2014). Decline and depletion rates of oil productions: a comprehensive investigation. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 372(2006), 0120448.
4. Mohd Noor, M.A.M.B. (2021). Environmental impacts of oil industry: An overview of the impacts and source management. EEEE Environmental Management, 0(0), 1-8.
5. Hu, B, Gu, Z., Zhou, C., et. al. (2022). Investigation of the effect of capillary barrier on water–oil movement in water flooding. Applied Sciences, 12(12), 6285-6314.
6. Nasybullin, A. V., Persova, M. G., Lutfullin, A. A., at. al. (2024). Forecasting the efficiency of waterflooding, thermal and chemical enhanced oil recovery methods in Bobrikovian reservoirs. SOCAR Proceedings, 2, 30-40.
7. Siqveland, L. M., Skjæveland, S. M. (2021). Derivations of the Young–Laplace equation. Capillarity, 4(2), 23–30.
8. Kazimov, F. K., Rzayeva, S. C., Mammadov, K. A. (2026). Development of a new method for treating the near-wellbore zone of water-flooded wells. SOCAR Proceedings, SI1, 69-74.
9. Sugihardjo, S. (2002). Interfacial tension between injecting fluid and reservoir oil at elevated pressure and temperature. Scientific Contributions Oil and Gas, 30(1), 1-6.
10. Soltanbekova, K. A., Ramazanova, G. I., Eremin, N. A., et al. (2024). Prospects and current state of chemical EOR methods applied in Kazakhstan. SOCAR Proceedings, 2, 71–79. 
11. Guseinova, R. K., Kazimov, F. K., Rzaeva, S. D., et. al. (2018). Experimental studies on improving oil displacement efficiency in layered heterogeneous formations. Karotazhnik, 3(285), 93–98.
12. Kazimov, F. K. (2018). A new method for the development of heterogeneous reservoirs with low- and high-permeability zones. GeoScience, 2, 39–46.
13. Shamilov, V. M., Babayev, E. R., Mammadova, P. Sh., et al. (2023). Some aspects of the use of carbon nanotubes for enhanced oil recovery. SOCAR Proceedings, SI 1, 115-120.
14. Bissembayeva, K. T., Mamalov, E. N., Hadiyeva, A. S., et al. (2024). An enhanced oil recovery technology applicable to Kazakhstan deposits with highly viscous oils. SOCAR Proceedings, 1, 107-111.
15. Jamalov, I. M., Gasimli, A. M., Kazimov, F. K. (2006). On increasing the reservoir sweep efficiency during oil displacement. Scientific Works. Baku, ASRPIOGI, 6, 104–108.
16. Qasımlı, A. M., Kazimov, F. K., Rzayeva, S. C., et. al. (2012). Development of a new composition for extracting residual oil from a watered-out reservoir. In: Proceedings of the Scientific and Practical Conference “Khazarneftgazyataq-2012”, Baku.
17. Salavatova, R. Sh., Bayramov, S. B., Kazimov, F. K. (2006). Development of a new composition for enhancing oil recovery from reservoirs with hard-to-recover reserves. Scientific Works. ASOA, SRI “Geotechnological Problems of Oil, Gas and Chemistry”, VII, 162–167.
18. Bagirov, M. K., Kasumov, A. M., Kazimov, F. K. (2002). The study of expulsion of oil alkaline waste solution from stratum having difficult recovered oil deposits. In: 6th Baku International Congress “Energy, Ecology, Economy”, Baku.
19. Ismaylov, F. S., Suleymanov, B. A., Ibrahimov, Kh. M., et al. (2017). Method for developing a water-flooded reservoir. Eurasian Patent EA030225.
20. Wang, J., Wan, X., Ren, J., et. al. (2025). Chemical incompatibility between formation and injection water: implications for oil recovery in porous media. Frontiers in Chemistry, 13, 1621714.
21. Razavirad, F., Heidari, S., Shahrabadi, A. (2024). Evaluation of compatibility between formation and injection water into the reservoir rock. Colloids And Surfaces A: Physicochemical And Engineering Aspects, 690, 133787.
22. Gong, Z., Zhang, L., Zhang, T., et. al. (2024). Evaluation of the compatibility between formation and injection water in ultra-low permeability reservoirs. Processes, 12(11), 2475.
23. Sheng, J. J. (2014). A comprehensive review of alkaline-surfactant-polymer (ASP) flooding. Asia-Pacific Journal of Chemical Engineering, 9, 71-489.
24. Gbadamosi, A. O., Junin, R., Manan, M. A., et al. (2019). An overview of chemical enhanced oil recovery: recent advances and prospects. International Nano Letters, 9(3), 1-32.
25. Sheng, J. J. (2015). Status of alkaline flooding technology. Journal of Petroleum Engineering & Technology, 5(1), 44-50.
26. Sheng, J. J. (2015). Investigation of alkaline–crude oil reaction. Petroleum, 1(1), 31-39;
27. Hadiyeva, A. S., Mamalov, Y. N., Bissembayeva, K. T., et. al. (2026). Methodology for determining the optimal concentration of an alkali solution for enhanced oil recovery. SOCAR Proceedings, 1, 65-69.
28. Khlaifat, A. L., Dakhlallah, D., Sufyan, F. (2022). A critical review of alkaline flooding: mechanism, hybrid flooding methods, laboratory work, pilot projects, and field applications. Energies, 15(10), 3820.
29. Thomas, N. C., Ghosh, B., Al-Ameri, W. S., et. al. (2016). Alkali and hybrid-alkali flooding as a tertiary oil recovery mode: prospects and challenges. International Journal of Petroleum and Petrochemical Engineering (IJPPE), 2(2), 22-31.
30. Pei, H., Zhang, G., Ge, J., et.al. (2013). Potential of alkaline flooding to enhance heavy oil recovery through waterin-oil emulsification. Fuel, 104, 284-293.
31. Sandeep, R., Jain, S., Agrawal, A., et al. (2020). Composition for enhanced oil recovery injection fliud and process thereof. Indian Patent № 202011045415.
32. Kazimov, F. (2020). Research of enhanced oil recovery method in layered-heterogeneous formations. In: 7th International Conference on Control and Optimization with Industrial Applications (COIA 2020), Baku, Azerbaijan, 26-28 August.
33. Hu, X., Hu, S., Jin, F., et al. (2017). Physics of petroleum reservoirs. Springer Geophysics.
34. Najar, I. M., Al-Naser, H. M. (2021). Fundamentals of petroleum reservoir engineering (fluid and rock properties). Saarbrücken, Germany: Noor Publishing.
35. Montgomery, D. C. (2017). Design and analysis of experiments. 9th Ed. John Wiley & Sons.
36. Devore, J. L. (2016). Probability and statistics for engineering and the sciences. 9th Ed. Cengage Learning.
37. Miller, I., John, E. (2014). Freund's mathematical statistics with applications. 8th Ed. Pearson Education.
38. Haken, H. (1983). Synergetics: an introduction. Nonequilibrium phase transitions and self-organization in physics, chemistry and biology. Berlin: Springer-Verlag.
39. Haken, H. (2006). Information and self-organization: a macroscopic approach to complex systems. 3rd Ed. Berlin, Heidelberg: Springer-Verlag.
40. An, Y., Yao, X., Zhong, J., et.al. (2022). Enhancement of oil recovery by surfactant-polymer synergy flooding: A review. Polymers and Polymer Composites, 30, 1-9.
41. Esfandiarian, A., Azdarpour, A., Santos, R. M., et al. (2020). Mechanistic investigation of LSW/surfactant/alkali synergism for enhanced oil recovery: fluid–fluid interactions. ACS Omega, 5(46), 30059–30072.
42. Taheri, K., Hosseini Majd, S. H., Ghanbarian, B., et al. (2025). A synergistic approach to enhanced oil recovery by combining in-situ surfactant production and wettability alteration in carbonate reservoirs. Scientific Reports, 15, 11688.
43. He, H., Liu, W., Chen, Y., et al. (2022). Synergistic mechanism of well pattern adjustment and heterogeneous phase combined flooding on enhancing oil recovery in mature fault-block reservoirs. Journal of Petroleum Exploration and Production Technology, 12, 3387-3398.

The presented article reviews and evaluates contemporary engineering solutions aimed at optimizing the operating modes of gas-lift wells in modern oil field operations. Within this study, the estimation of the current performance and energy efficiency of gas-lift systems using real-time field data is considered of particular importance for sustainable production. To achieve this, efficiency factor (η) of the lifting system was meticulously calculated for selected wells where a reliable database of operational parameters was available. For the analytical part of this research, the specialized methodology developed by A. S. Alasgarov was utilized as the primary evaluative framework. To investigate operational efficiency based on actual surface parameters, and to identify candidates for production enhancement - specifically those where targeted technological interventions could yield positive results – a detailed joint analysis of the aforementioned well parameters was conducted. Based on extensive field data, the individual operating modes of several gas-lift wells were investigated under various conditions. The results revealed that in five specific wells characterized by exceptionally high water cut levels, the overall lifting efficiency decreased drastically, ranging from 44.5 to 82 %. To mitigate these losses and restore productivity, it is recommended that the effectiveness of bottomhole and reservoir stimulation methods against water cut be further evaluated for the respective wells. Finally, to enhance operational efficiency, the optimization of wells with similar fluid and pressure parameters was addressed by categorizing them into distinct diagnostic groups based on multi-variable criteria.

Keywords: gas lift operation method; optimization of operation mode; gas injection rate; well efficiency; similarity criterion.

Date submitted: 06.05.2025     Date accepted: 12.11.2025     Date published: 30.07.2026

References

1. Ghassemzadeh, S., Pourafshary, P., Jung, S.-Y., et al. (2015). Optimization of gas lift allocation for improved oil production under facilities constraints. Industrial & Engineering Chemistry Product Research and Development, 5(3), 39-47.
2. Mahdiania, M. R., Khamehchia, E., Suratgarb, A. A. (2019). Using modern heuristic algorithms for optimal control of a gas lifted field. Journal of Petroleum Science and Engineering, 183, 106348.
3. Namdar, H. (2019). Developing an improved approach to solving a new gas lift optimization problem. Journal of Petroleum Exploration and Production Technology, 9, 2965–2978.
4. Mazhar, A., Muhammad, K. M. (2018). Oil production optimization with gas lift method. International Journal of Current Engineering and Technology, 8(6), 1628-1634.
5. Abdalsadig, M. A. G. H., Nourian, A., Nasr, G. G., Babaie, M. (2016). Gas lift optimization to improve well performance. World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, 10(3), 419-427.
6. Aliev, F. A., Mutallimov, M. M., Mamedova, Y. V. (2026). Optimal stabilization of oil production using gas lift in steady-state regime. SOCAR Proceedings, 1, 174-178.
7. Rashid, K., Bailey, W., Couet, B. (2012). A survey of methods for gas-lift optimization. Modelling and Simulation in Engineering, 2012, 516807.
8. Temirbekov, N. M., Turarov, A. K., Aliev, F. A., Temirbekov, A. N. (2025). Solutıon of the direct and inverse problem of gas lift oil production process by the optimal control method. SOCAR Proceedings, 2, 104-116.
9. Abdullayev, V. J., Huseynov, M. A., Mammadov, R. R. (2024). Research methods of the potential of long-term operated reservoirs based on the hydrodynamic model. SOCAR Proceedings, SI1, 84-88.
10. Sreenivasan, H., Patel, J., Jain, D., et al. (2024). Optimization of gas lift system for well performance improvement in Asmari formation: A techno-economic perspective. Petroleum Research, 9(1), 115-124.
11. Danilović, D., Ilić, M., Crnogorac, M., Tomić, L. (2022). Gas-lift wells optimization at the oil field «k». Podzemni Radovi, 41, 31-42.
12. Faria, R. R., Capron, B. D. O., Secchi, A. R., Souza, M. B. Jr. (2024). Gas-lift optimization using physics-informed deep reinforcement learning. Industrial & Engineering Chemistry Research, 63(32), 14199–14210.
13. Wang, Q., Yang, Z., Zeng, L., et al. (2025). Research on the optimization of continuous gas lift production from multiple wells on the platform. Processes, 13, 478.
14. Hagedorn, A. R., Brown, K. E. (1965). Experimental study of pressure gradients occurring during continuous twophase flow in small-diameter vertical conduits. SPE Journal of Petroleum Technology, 17(04), 475–484.
15. Yegani, M. (2018). Design and optimization of gas lift wells using PROSPER software. Journal of Petroleum Exploration and Production Technology, 8(1), 211–220.
16. Elahi, A., Amani, M. (2021). Optimization of gas lift parameters using Schlumberger’s PIPESIM simulator. In: SPE Middle East Oil and Gas Show and Conference.
17. Zhang, H., Sarica, C., Brill, J. P. (2017). Use of OLGA for transient modeling of gas-lifted wells. Journal of Natural Gas Science and Engineering, 45, 628–636.
18. Brown, K. E. (1984). The technology of artificial lift methods: gas lift. Penn Well Books.
19. Abdullayev, V. J., Gamzaev, Kh. M. (2024). A method for computing the pressure distribution in the elastic mode of single-well formation development. SOCAR Proceedings, 2, 80-84.
20. Abdullayev, V. J., Huseynov, M. A. (2026). Assessment of enhanced oil recovery methods based on hydrodynamic model. SOCAR Proceedings, 1, 54-64.
21. Abdullaev, V. J. (1996). On increasing the efficiency of gas lift wells. Scientific Conference of the Academy of Sciences of Azerbaijan, Baku.
22. Abdullayev, V. J. (1995). Methodology for calculating shoe pressure in gas lift wells. Izvestia of the Academy of Sciences of Azerbaijan, Earth Sciences Series, 101-107.

A multifunctional corrosion inhibitor–biocide composition was developed using fatty acid imidazolines synthesized from soapstock, a waste by-product of vegetable oil refining. The imidazoline compounds were obtained via a one-step reaction between soapstock and aminoethylethanolamine (AEEA) at 170–220 °C for 8 h. The chemical structure of the synthesized imidazolines was characterized by FTIR and ¹H NMR spectroscopy, which verified the formation of the imidazoline ring as well as the presence of long hydrocarbon chains derived from fatty acids. The ¹H NMR results confirmed the synthesis of imidazoline by the presence of equivalent triplet signals of the methylene groups in the imidazoline ring at δ = 3.28 and 3.70 ppm. The probable mechanism for the one-step synthesis of imidazolines from soapstock has been proposed. The corrosion inhibition performance of synthesized composition was evaluated in a CO₂-saturated 3.5 wt.% NaCl solution using linear polarization resistance (LPR) measurements. The results showed a significant reduction in corrosion rate and metal loss compared to the blank solution. Inhibition efficiency increased with concentration and reached an optimum value at 100 ppm, achieving approximately 84–85 % protection efficiency. Microbiological tests against sulfate-reducing bacteria (SRB) demonstrated strong biocidal activity, with inhibition efficiency 100% at 80-100 ppm. This indicates that the synthesized composition, at its optimal concentration, completely eliminates microorganisms responsible for microbiologically influenced corrosion (MIC). Overall, the developed inhibitor-biocide composition exhibits dual functionality as both a corrosion inhibitor and biocide, effectively mitigating CO₂ corrosion and MIC. 

Keywords: aminoethylethanolamine; imidazoline; CO₂ corrosion; potentiostat; electrochemical measurements; biocide.

Date submitted: 06.05.2025     Date accepted: 12.11.2025     Date published: 30.07.2026

References

1. Nesic, S. (2007). Key issues related to modelling of internal corrosion of oil and gas pipelines – A review. Corrosion Science, 49(12), 4308–4338.
2. Chernov, V. Y., Makarenko, V. D., Kryzhanivs’kyi, E. I., Shlapak, L. S. (2002). Causes and mechanisms of local corrosion in oil-field pipelines. Materials Science, 38(5), 729–737.
3. Abbasova, S. V., Karazhanova, M. K., Zhetekova, L. B., et al. (2024). X-ray phase analysis of the composition and size of sedimentary mechanical impurities in the working components of submersible pump equipment. SOCAR Proceedings, 4, 94–101.
4. Anselmo, N., May, J. E., Mariano, N. A., et al. (2006). Corrosion behavior of supermartensitic stainless steel in aerated and CO₂-saturated synthetic seawater. Materials Science and Engineering: A, 428(1–2), 73–79.
5. Yotapan, N., Sriplai, N., Ruengsangtongkul, S., Sombatmankhong, K. (2024). Imidazoline as a volatile corrosion inhibitor for mitigation of top- and bottom-of-the-line CO₂ corrosion in carbon steel pipelines. Langmuir, 40(23), 11888–11902.
6. Sahu, B. C. (2015). Organic corrosion inhibitors. In: Introduction to corrosion - basics and advances. IntechOpen.
7. Tamalmani, K., Husin, H. (2020). Review on corrosion inhibitors for oil and gas corrosion issues. Applied Sciences, 10(10), 3389.
8. Finšgar, M., Jackson, J. (2014). Application of corrosion inhibitors for steels in acidic media for the oil and gas industry: A review. Corrosion Science, 86, 17–41.
9. Nwigwe, U. S., Ezeanyaeji, C. S., Ikwechegh, O. D., et al. (2025). Synthesis of new bioactive leaf extract for corrosion inhibition of steel pipelines in the acidic medium of oil and gas industry. SOCAR Proceedings, 1, 85–91.
10. Li, X., Zhao, Y., Wang, J. (2022). Effect of glutaraldehyde as a biocide against the microbiologically influenced corrosion of X80 steel pipeline. Journal of Pipeline Systems Engineering and Practice, 13(3), 04022014.
11. Cai, D., Wu, J., Chai, K. (2021). Microbiologically influenced corrosion behavior of carbon steel in the presence of marine bacteria Pseudomonas sp. and Vibrio sp. ACS Omega, 6(5), 3780–3790.
12. Shi, X., Zhang, R., Sand, W., et al. (2023). Comprehensive review on the use of biocides in microbiologically influenced corrosion. Microorganisms, 11(9), 2194.
13. Zhao, J., Chen, G. (2012). The synergistic inhibition effect of oleic-based imidazoline and sodium benzoate on mild steel corrosion in a CO₂-saturated brine solution. Electrochimica Acta, 69, 247–255.
14. Hamadi, L., Mansouri, S., Oulmi, K., Kareche, A. (2018). The use of amino acids as corrosion inhibitors for metals: a review. Egyptian Journal of Petroleum, 27(4), 1157–1165.
15. Sastri, V. S. (1998). Corrosion inhibitors: principles and applications. Chichester: Wiley.
16. Ismayılov, O. D., Shabanova, Z. A., Sultanov, E. F., Veliyev, F. Q. (2019). Development and protective properties of bactericide inhibitor hydrogen and microbiological corrosion of steel based on nitrogen-containing compounds. SOCAR Proceedings, 3, 29–32.
17. Amiraslanova, M. N., Mamedzade, F. A., Rustamov, R. A., et al. (2025). Obtaining of oligomeric oxypropylates of imidazolines for collecting oil spills from the surface of natural waters. SOCAR Proceedings, 4, 151–157.
18. Abbasov, V. M., Dadashova, N. K., Mursalov, N. I., et al. (2025). Investigation of the inhibitory properties of natural petroleum acid amides in CO₂-containing environment. SOCAR Proceedings, 3, 130–136.
19. Abbasov, V. M., Kangarli, A. A., Aghamaliyeva, D. B., et al. (2026). Preparation of oleic acid–based corrosion inhibitor reagents for application in various aggressive environments of the oil and gas industry. SOCAR Proceedings, 2, 128-132.
20. NACE International. (2014). TM0194-2014: Field monitoring of bacterial growth in oil and gas systems. Houston, TX: NACE International.

The paper presents a comprehensive study of geomechanical mechanisms of sand production and approaches to its prediction in weakly cemented reservoirs of oil and gas fields of the Absheron Peninsula (Azerbaijan). The region is characterized by high structural and tectonic complexity, pronounced lithological heterogeneity, the presence of decompaction zones and mud-volcanic activity, as well as a long (up to 50–100 years) production history, which results in an increased tendency of formations to failure and sand production during well operation. Based on a synthesis of domestic and international studies, as well as an analysis of typical geological and geomechanical parameters of the Bibi-Heybat, Lokbatan–Kushkhana–Puta, Oil Rocks, Palchig Pilpilesi, and Azeri–Chirag–Gunashli fields, the key mechanisms of sand production are considered: an increase in effective stresses due to reservoir pressure depletion, shear and granular failure of weakly cemented sandstones, and hydrodynamic erosion at elevated filtration velocities. The main sand prediction models are analyzed and compared, including the Critical Drawdown Pressure (CDP) model, the Mohr–Coulomb failure criterion, and the coupled hydromechanical plastic flow and erosion model proposed by Papamichos. It is shown that for most traditional Absheron fields, critical drawdown pressures fall within the range of −3 to 1 MPa, indicating a high to very high risk of sand production even at moderate production rates. An exception is represented by the stronger sandstones of the Azeri–Chirag–Gunashli field, where sand production is more localized and mainly associated with production intensification.

Keywords: sand production; weakly cemented formations; Absheron Peninsula; geomechanics; drawdown; critical rate; sand control. 

Date submitted: 07.01.2026     Date accepted: 05.05.2026     Date published: 31.07.2026

References

1. Suleimanov, B. A., Abbasov, H. F., Ismailov, Sh. Z. (2024). A comprehensive review on sand control in oil and gas wells. Part I. mechanical techniques. SOCAR Proceedings, 3, 9–23.
2. Iskandarov, E. Kh., Harbizade, M. E., Yergali, A., Javadov, M. A. (2026). Development of design principles for offshore supersonic sand separators during production decline in gas-condensate fields. SOCAR Proceedings, SI1, 144–152.
3. Tapdiqov, Sh. Z., Taghiyev, D. B. (2024). Application of kinetic results of doxorubicin release from polyacrylic acidbased hydrogel to Higuchi, Korsmeyer-Peppas, Hixon-Crowell equations. SOCAR Proceedings, SI1, 130-135.
4. Ismayilov, Sh. Z., Suleymanov, A. A. (2025). Diagnosis of operational complications in gas-lift wells based on wellhead data analysis. SOCAR Proceedings, SI1, 47–52.
5. Abdelghany, W. K., Hammed, M. S., Radwan, A. E., Nassar, T. (2023). Implications of machine learning on geomechanical characterization and sand management: a case study from Hilal field, Gulf of Suez, Egypt. Journal of Petroleum Exploration and Production Technology, 13(1), 297–312.
6. Suleimanov, B. A., Abbasov, H. F. (2024). A comprehensive review on sand control in oil and gas wells. Part II. Chemical treatment and sand management. SOCAR Proceedings, 4(4), 33-40.
7. Salehi, M. B., Moghadam, A. M., Marandi, S. Z. (2019). Polyacrylamide hydrogel application in sand control with compressive strength testing. Petroleum Science, 16(1), 94–104.
8. Marandi, S. Z., Salehi, M. B., Moghadam, A. M. (2018). Sand control: experimental performance of polyacrylamide hydrogels. Journal of Petroleum Science and Engineering, 170, 430-439.
9. Ahad, N. A., Jami, M., Tyson, S. (2020). A review of experimental studies on sand screen selection for unconsolidated sandstone reservoirs. Journal of Petroleum Exploration and Production Technology, 10(4), 1675–1688.
10. Al-Qasim, A., Sharidah, A., Muhannad, A., Mutaz, A. (2021). Expanding the envelope of fiber-optic sensing for reservoir description and dynamics. In: SPE Trinidad and Tobago Section Energy Resources Conference, Virtual, June. Society of Petroleum Engineers.
11. Araujo-Guerrero, E. F., Morales-Monsalve, C. B., Alzate-Espinosa, G. A., Arbelaez-Londoño, A. (2022) Numerical model for predicting and evaluating sand production in weakly consolidated reservoirs. DYNA, 89(220), 54–63.
12. Marandi, S. Z., Sefti, M. V., Salehi, M. B., et al. (2017). Sand control: applying hydrogels as new method in oil reservoirs. Nashrieh Shimi va Mohandesi Shimi Iran, 36(1), 215-227.
13. Aroyehun, M. E., Oko, F. N., Onyeanusi, O., et al. (2018). Comparative study of sand control methods in selected niger-delta sand stone reservoirs. In: SPE Nigeria Annual International Conference and Exhibition, Lagos, Nigeria, August. Society of Petroleum Engineers.
14. Geuzaine, C., Remacle, J.-F. (2009). Gmsh: A 3-D finite element mesh generator with built-in pre-and post-processing facilities. International Journal for Numerical Methods in Engineering, 79(11), 13091331.
15. Junmano, T., Lee, B., Grant, G., et al. (2015). Sand production management the critical challenge in Zawtika Gas Production. In: International Petroleum Technology Conference, Bangkok, Thailand, November. Society of Petroleum Engineers.
16. Zhou, S., Sun, F. (2016). Sand production mechanism and changes of rock properties affected by sand production. In: Sand production management for unconsolidated sandstone reservoirs (Eds. S. Zhou and F. Sun). Wiley.
17. Gui, F., Khaksar, A., Zee, W. V. D., Cadogan, P. (2016). Improving the sanding evaluation accuracy by integrating core tests, field observations and numerical simulation. In: SPE Asia Pacific Oil & Gas Conference and Exhibition, Perth, Australia, October. Society of Petroleum Engineers.
18. Wu, B., Choi, S. K., Denke, R., et al. (2016). A new and practical model for amount and rate of sand production estimation. In: Offshore Technology Conference Asia, Kuala Lumpur, Malaysia, March. Society of Petroleum Engineers.
19. Wang, H., Cardiff, P., Sharma, M. M. (2016). A 3-D poro-elasto-plastic model for sand production around openhole and cased and perforated wellbores. In: 50th U.S. Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Association, Houston, TX.
20. Wang, H., Sharma, M. M. (2016). A fully 3-D, multi-phase, poro-elastoplastic model for sand production. In: SPE Annual Technical Conference and Exhibition, Dubai, UAE, September. Society of Petroleum Engineers.
21. Fan, Z., Yang, D. (2017). Quantification of sand production by use of a pressure-gradient-based sand failure criterion. In: SPE Canada Heavy Oil Technical Conference, Calgary, Alberta, Canada, February. Society of Petroleum Engineers.
22. Saghandali, F., Salehi, M. B., Hosseinzadehsemnani, R., et al. (2022). A review on chemical sand production control techniques in oil reservoirs. Energy Fuels, 36(10), 5185–5208.
23. Saghandali, F., Salehi, M. B., Taghikhani, V. (2023). Design and fabrication of a preformed thixotropic-viscoelastic nanocomposite hydrogel system (PNCH) for controlling sand production in reservoirs. Results in Engineering, 18, 101089.
24. Saghandali, F., Salehi, M. B., Taghikhani, V., Saviz, S. (2023). Investigating the performance of Co [AM-AMPSMALEICAAC]/PEI-MBA nanocomposite hydrogel in sand control from oil reservoirs. Petroleum & Petrochemical Engineering Journal, 7(2), 1-11.
25. Ajayi, T. J., Adeogun, O. Y., Omeru, T. (2022). Predicting sanding potential using empirical method in “Ebendo” field, Niger Delta, Nigeria. Journal of Applied Sciences and Environmental Management, 26(9), 1557–1564.
26. Aminu, K. T., McGlinchey, D., Chen, Y. (2019). Optimal design for realtime quantitative monitoring of sand in gas flowline using computational intelligence assisted design framework. Journal of Petroleum Science and Engineering, 177, 1059–1071.
27. Shinohara, T., Thieulot, C., Spiers, C. J., Hangx, S. J. T. (2025). Non-Hertzian stress fields in simulated porous sandstone grains and implications for compactive brittle failure—a high-resolution fem approach. , 130(6), e2024JB030818.

Corrosion of carbon steel, especially in CO2-containing environments, remains one of the major operational challenges in the oil and gas industry. This study describes a two-step synthesis method for a corrosion inhibitor, involving the hydrolysis of corn oil followed by amidation of the resulting fatty acids with aniline. The synthesis was carried out under laboratory conditions, and the yield of the aniline amide of corn oil fatty acids was 92%. A conceptual process flow diagram was also proposed to ensure scalability and control of key parameters. The synthesized aniline amide of corn oil fatty acids (AACFA) was characterized using FTIR and NMR (1H and 13C) spectroscopy, confirming its chemical structure and successful synthesis. The corrosion inhibition efficiency was investigated using the linear polarization resistance (LPR) method in a 1% aqueous NaCl solution saturated with CO2 at 50 °C, at various inhibitor concentrations (10, 25, 50, and 100 ppm). It was found that the corrosion rate decreased with increasing inhibitor concentration, with a maximum inhibition efficiency of 92.1% at 100 ppm. The behavior of the aniline amide of corn oil fatty acids on the steel surface followed the Langmuir adsorption isotherm, and thermodynamic parameters indicated a spontaneous chemisorption process (ΔG⁰_ads ≈ 41 kJ/mol). The inhibitor exhibits favorable physicochemical properties, including good solubility and the ability to form a protective film. These findings demonstrate that the synthesized compound is an effective and environmentally friendly corrosion inhibitor for carbon steel under conditions simulating oil and gas industry environments.

Keywords: CO₂ corrosion; corrosion inhibitor; fatty acid amide; corn oil; aniline; Langmuir isotherm; linear polarization resistance.

Date submitted: 07.11.2025     Date accepted: 07.05.2026     Date published: 31.07.2026

References

1. Li, Z. L. (2017). An empirical study on technological innovation and corporate competitiveness of listed coal-toliquids companies in China. China Equipment Engineering, 13, 156–157.
2. Fateh, A., Aliofkhazraei, M., Rezvanian, A. R. (2020). Review of corrosive environments for copper and its corrosion inhibitors. Arabian Journal of Chemistry, 13(1), 481–544.
3. Jeeva, M., Prabhu, G. V., Boobalan, M. S., Rajesh, C. M. (2015). Interactions and inhibition effect of urea-derived Mannich bases on a mild steel surface in HCl. Journal of Physical Chemistry C, 119, 22025–22043.
4. Olasunkanmi, L. O., Obot, I. B., Kabanda, M. M., Ebenso, E. E. (2015). Some quinoxalin-6-yl derivatives as corrosion inhibitors for mild steel in hydrochloric acid: Experimental and theoretical studies. Journal of Physical Chemistry C, 119, 16004–16019.
5. Finšgar, M., Jackson, J. (2014). Application of corrosion inhibitors for steels in acidic media for the oil and gas industry: A review. Corrosion Science, 86, 17–41.
6. Liu, Y., Zou, C., Yan, X., et al. (2015). β-Cyclodextrin modified natural chitosan as a green inhibitor for carbon steel in acid solutions. Industrial & Engineering Chemistry Research, 54, 5664–5672.
7. Dardeer, H. M., Abdel-Hakim, M., Aly, K. I., Sayed, M. M. (2023). Modification of conducting arylidene copolymers by formation of inclusion complexes: Synthesis, characterization, and applications as highly corrosion inhibitors for mild steel. BMC Chemistry, 17(1), 77.
8. Yang, C. (2018). Efficacy of Lenvatinib, a multitargeted tyrosine kinase inhibitor, on laser-induced CNV mouse model of neovascular AMD. Journal of Chemical Management, 10, 168.
9. John, S., Jeevana, R., Aravindakshan, K. K., Joseph, A. (2017). Corrosion inhibition of mild steel by N(4)-substituted thiosemicarbazone in hydrochloric acid media. Egyptian Journal of Petroleum, 26(2), 405–412.
10. Bedair, M. A., Abuelela, A. M., Melhi, S., et al. (2024). Highly effective inhibition of steel corrosion in 1.0 M HCl solution using a novel non-ionic surfactant with coumarin moiety: Practical and computational studies. Materials Chemistry and Physics, 312, 128644.
11. Ech-Chebab, A., Dahmani, K., Hsissou, R., et al. (2023). Anticorrosion properties of the epoxy polymer TGETBAU for mild steel in a solution of HCl (1.0 M): Experimental and computational approaches. Journal of Molecular Structure, 1284, 135441.
12. Yousif, Q. A., Fadel, Z., Abuelela, A. M., et al. (2023). Insight into the corrosion mitigation performance of three novel benzimidazole derivatives of amino acids for carbon steel (X56) in 1 M HCl solution. RSC Advances, 13, 13094–13119.
13. Dahmani, K., Galai, M., Ech-Chebab, A., et al. (2023). Investigating the inhibitory properties of Cupressus sempervirens extract against copper corrosion in 0.5 M H₂SO₄: Combining quantum and electrochemical-surface studies. ACS Omega, 8, 24218–24232.
14. Amin, H. M. A., Galal, A. (Eds.). (2021). Corrosion protection of metals and alloys using graphene and biopolymer-based nanocomposites. CRC Press.
15. Titaley, I. A., Khattak, J., Dong, J., et al. (2022). Neutral per- and polyfluoroalkyl substances, butyl carbitol, and organic corrosion inhibitors in aqueous film-forming foams: Implications for vapor intrusion and the environment. Environmental Science & Technology, 56(15), 10785–10797.
16. Jalab, R., Ben Ali, A., Khaled, M., et al. (2023). Novel polyepoxysuccinic acid-grafted polyacrylamide as a green corrosion inhibitor for carbon steel in acidic solution. ACS Omega, 8(19), 16673–16686.
17. Dadashova, N. K. (2020). Synthesis of amides of aniline and benzylamine of natural petroleum acids and their use as the components of preserving fluids. PPOR, 21(1), 146–154.
18. Dadashova, N. K., Abbasov, V. M., Mamadov, E. A., et al. (2023). Study of bactericidal properties of amides based on natural petroleum acid and amines. Theory and Practice of Corrosion Protection, 28(3), 18–26.
19. Mursalov, N. I. (2018). Inhibition of carbon dioxide corrosion of mild steel via bisimidazoline compounds. PPOR, 19(2), 156–165.
20. Abbasov, V. M., Mammadbeyli, E. H., Agamaliyeva, D. B., et al. (2017). Effect of inorganic complexes of imidazoline based on synthetic petroleum acids and triethylenetetramine against carbon dioxide corrosion. Kimya Problemleri, 4, 364–369.
21. Abbasov, V. M., Aghamaliyeva, D. B., Afandiyeva, L. M., et al. (2024). The study of the effect of alkylhalogenide complexes of amidoamine of corn oil on the kinetics of CO₂ corrosion. PPOR, 25(2), 313–322.
22. Abbasov, V. M., Dadashova, N. K., Mursalov, N. I., et al. (2025). Investigation of the inhibitory properties of natural petroleum acid amides in CO₂-containing environment. SOCAR Proceedings, 3, 130-136.
23. Yotapan, N., Sriplai, N., Ruengsangtongkul, S., Sombatmankhong, K. (2024). Imidazoline as a volatile corrosion inhibitor for mitigation of top- and bottom-of-the-line CO₂ corrosion in carbon steel pipelines. Langmuir, 40(23), 11888-11902.
24. Wang, B., Du, M., Zhang, J., et al. (2019). Corrosion inhibition of mild steel by the hydrolysate of an imidazoline-based inhibitor in CO₂-saturated solution. RSC Advances, 9(63), 36546–36557.
25. Jia, S., Xiong, L., Du, S., et al. (2025). Thiophene-imidazoline derivatives as corrosion inhibitors for carbon steel in CO₂-saturated produced water. RSC Advances, 15(38), 31632-31650.
26. Okafor, P. C., Liu, C. B., Zhu, Y. J., Zheng, Y. G. (2011). Corrosion and corrosion inhibition behavior of N80 and
    P110 carbon steels in CO₂-saturated simulated formation water by rosin amide imidazoline. Industrial & Engineering Chemistry Research, 50(12), 7273-7281.
27. Shamsa, A., Barker, R., Hua, Y., et al. (2021). Impact of corrosion products on performance of imidazoline corrosion inhibitor on X65 carbon steel in CO₂ environments. Corrosion Science, 185, 109423.
28. Abbasov, V. M., Kangarli, A. A., Aghamaliyeva, D. B., et al. (2026). Preparation of oleic acid–based corrosion inhibitor reagents for application in various aggressive environments of the oil and gas industry. SOCAR Proceedings, 2, 128–132.
29. Ismayilov, T. A., Abbasov, V. M., Ismayilov, I. T., et al. (2025). Effectiveness of propylamide derivatives of ethylenediaminetetraacetic acid against corrosion and salt deposition problems. SOCAR Proceedings, 4, 158–166.
30. Shamsa, A., Barker, R., Hua, Y., et al. (2020). Performance evaluation of imidazoline corrosion inhibitors in CO₂-saturated environment with emphasis on localised corrosion. Corrosion Science, 176, 108916.
31. Zhang, C., Duan, H., Zhao, J. (2016). Synergistic inhibition effect of imidazoline derivative and l-cysteine on carbon steel corrosion in a CO₂-saturated brine solution. Corrosion Science, 112, 160-169.
32. Abbasov, V. M., Abd El-Lateef, H. M., Aliyeva, L. I., et al. (2013). A study of the corrosion inhibition of mild steel C1018 in CO₂-saturated brine using some novel surfactants based on corn oil. Egyptian Journal of Petroleum, 22(4), 451–470.
33. Abbasov, V. M., Mammadov, E. A., Dadashova, N. K., et al. (2024). The inhibition efficiency of nitrated cottonseed oil on corrosion of mild carbon steel in CO₂ medium. PPOR, 25(3), 631–640.
34. Gunstone, F. D. (2002). Vegetable oils in food technology: composition, properties and uses. Blackwell Publishing.
35. Ismayilov, I. T., Abd El-Lateef, H. M., Abbasov, V. M., et al. (2014). Adsorption and corrosion inhibitive properties of novel surfactants in the series of fatty acids based on palm oil on carbon steel in CO₂-containing solution. International Research Journal of Pure & Applied Chemistry, 4(3), 299–314.
36. Bhardwaj, N., Sharma, P., Kumar, V. (2021). Triticum aestivum extract as corrosion inhibitor for stainless steel (SS-410) in acidic media: experimental and theoretical study. Current Opinion in Green and Sustainable Chemistry, 4, 100189.
37. Chen, S., Zhu, B., Huang, C., Li, W. (2020). Magnolia grandiflora leaves extract as a novel environmentally friendly inhibitor for Q235 steel corrosion in 1 M HCl: combining experimental and theoretical research. Journal of Molecular Liquids, 311, 113312.
38. Lin, B., Shao, J., Zhao, C., et al. (2023). Passiflora edulis Sims peel extract as a renewable corrosion inhibitor for mild steel in phosphoric acid solution. Journal of Molecular Liquids, 375, 121296.
39. Nwigwe, U. S., Ezeanyaeji, C. S., Ikwechegh, O. D., et al. (2025). Synthesis of new bioactive leaf extract for corrosion inhibition of steel pipelines in the acidic medium of oil and gas industry. SOCAR Proceedings, 1, 85–91.
40. Silva, M., Policarpi, E., Spinelli, A. (2021). Syzygium cumini leaf extract as an eco-friendly corrosion inhibitor for carbon steel in acidic medium. Journal of the Taiwan Institute of Chemical Engineers, 129, 342–349.
41. Tan, B., Zhang, S., Liu, H., et al. (2019). Insights into the inhibition mechanism of three 5-phenyltetrazole derivatives for copper corrosion in sulfuric acid medium via experimental and DFT methods. Journal of the Taiwan Institute of Chemical Engineers, 102, 424–437.
42. Wang, Q., Liu, L., Zhang, Q., et al. (2022). Insight into the anti-corrosion performance of Artemisia argyi leaves extract as eco-friendly corrosion inhibitor for carbon steel in HCl medium. Sustainable Chemistry and Pharmacy, 27, 100710.

The effect of metal nanoparticles on the interfacial activity of demulsifiers at the kerosene–distilled water interface was investigated using aluminum (50–70 nm), iron (40–60 nm), and copper (40–60 nm) nanoparticles. The study aimed to evaluate the influence of metallic nanoparticles on the performance of demulsifiers used in crude oil dehydration and desalting processes and to identify the optimum nanoparticle concentration for the development of highly efficient demulsifier formulations. Four commercially available water-soluble demulsifiers—Alkan DE-202B, Alkan DE-318A, ND-12, and Disolvan 4411—commonly applied in the treatment of water-in-oil emulsions containing salts and suspended solids were examined. Demulsifier solutions were prepared at concentrations of 0.01–0.05 wt.%, while nanoparticle concentrations ranged from 0.0005 to 0.01 wt.%. The results demonstrated that the incorporation of nanoparticles at concentrations of 0.001–0.005 wt.% reduced the interfacial tension of the demulsifier solutions by up to 60%, indicating a significant enhancement in interfacial activity. However, a slight increase in interfacial tension was observed at higher nanoparticle concentrations (0.005–0.01 wt.%), suggesting the existence of an optimum dosage. FTIR analysis confirmed that the incorporation of aluminum nanoparticles into the polyether matrix (Laprol-4202) did not alter its molecular structure. In addition, the viscosity of the commercial demulsifier Alkan DE-318A increased slightly from 69.0 to 74.0 mPa·s after the addition of 0.005 wt.% Al nanoparticles. The efficiency of the nanoparticle-modified demulsifiers was further evaluated using crude oil emulsions from the Buzovna and Gala oil fields. The modified formulations exhibited superior demulsification performance, achieving deeper dehydration of highly stable crude oil emulsions than the corresponding unmodified commercial demulsifiers. 

Keywords: demulsifier; Alkan DE-202B; Alkan DE-318A; Disolvan 4411; ND-12; aluminum nanoparticles; copper nanoparticles; iron nanoparticles; interfacial tension; demulsification; crude oil emulsion.

Date submitted: 18.02.2026     Date accepted: 02.07.2026     Date published: 31.07.2026

References

1. Shamilov, V., Babayev, E., Kalbaliyeva, E., Shamilov, F. (2017). Polymer nanocomposites for enhanced oil recovery. Materials Today: Proceedings, 4, S70–S74.
2. Mehrabova, M. A., Babayev, E., Kerimov, F. Sh., et al. (2025). Study of mechanical properties of the composition based on low-density polyethylene modified with carbon nanotubes. Reliability: Theory & Applications, Special Issue 7(83), 20, 410–419.
3. Mazitova, A. K., Zaripov, I. I., Aminova, G. K. (2023). Mineral fillers for polymer nanocomposites. SOCAR Proceedings, 1, 157-166.
4. Mehrabova, M. A., Mammadova, S. I., Kerimov, F. Sh., et al. (2024). Influence of discharges and UV irradiation on the electrical properties of high pressure polyethylene and compositions on its base. Polymer-Plastics Technology and Materials, 63(16), 2237–2245.
5. Shamilov, V. M., Babayev, E. R., Mammadova P. Sh. (2023). Production of modified multi-walled carbon nanotubes and their application for stimulation of oil recovery. SOCAR Proceedings, SI1, 115-120.
6. Suleimanov, B. A., Abbasov, H. F., Ismailov, Sh. Z. (2024). A comprehensive review on sand control in oil and gas wells. Part I. Mechanical techniques. SOCAR Proceedings, 3, 9-23.
7. Abdullayev, A. I., Hamashayeva, M. J., Shamilov, F. V., et al. (2024). Application of aluminum nanoparticles in reagents for oil viscosity reduction. SOCAR Proceedings, SI1, 17-21.
8. Asadova, G. Sh. (2026). Application of nanostructured systems in the isolation of lost circulation zones. SOCAR Proceedings, SI1, 32-38.
9. Suleimanov, B. A., Abbasov, H. F., Ismayilov, R. H. (2023). Thermophysical properties and stabilization mechanism of nano- and microfluids with [Ni₅(μ₅-pppmda)4Cl₂] metal string complex particles. SOCAR Proceedings, 2, 32-41.
10. Mirzajanzade, A. Kh., Yusifzade, Kh. B., Shahbazov, E. K., Kazimov, E.A. (2011). Scientific basis for the development and implementation of nanotechnologies in the oil industry. In: Nanoscience and nanotechnology. Encyclopedia of life support systems (EOLSS). UNESCO–EOLSS Publishers.
11. Shahbazov, E. K., Mursalova, M. A. (2016). Effect of low concentrations and perturbations: nano-surfactants for oil production processes. Baku: “OilGasScientificResearchProject” Institute Publishing House.
12. Mammadov, E. A., Mehrabova, M. A., Asadov, M. F., et al. (2025). Influence of magnetic field and reagents on structural and mechanical properties of high-resinity emulsion oils. Processes of Petrochemistry and Oil Refining, 26(4), 1254–1269.
13. Mammadov, E. A., Mehrabova, M. A., Asadov, M. F., et al. (2024). Development of complex acid compositions for the influence on the bottomhole formation zone. Processes of Petrochemistry and Oil Refining, 25(4), 1108–1120.
14. Ismailov, F. S., Suleimanov, B. A., Samedov, A. M., et al. (2012). Demulsifier. Patent RU 2443754.
15. Genkin, V. S., Lapiga, E. Ja., Mirzabekjan, G. Z., et al. (2000). Method for dehydration of water-in-oil emulsions. Patent RU 2167692.
16. Nazarenko, O. B., Shubin, B. G. (1999). Hydrocarbon liquid dehydration method. Patent RU 2174857.
17. Suzumura, H., Kaneko, M., Matsuura, I. (2000). Method and device for dehydrating heavy oils. U.S. Patent 6165360.
18. Faizullayev, S., Adilbekova, A., Kujawski, W., Mirzaeian, M. (2022). Recent demulsification methods of crude oil emulsions – brief review. Journal of Petroleum Science and Engineering, 215(Part B), 110643.
19. Ahmadi, S., Khormali, A. (2025). Petroleum emulsion stability and separation strategies: A comprehensive review. ChemEngineering, 9(5), 113.
20. Franco, C. A., Franco, C. A., Zabala, R. D., et al. (2021). Field applications of nanotechnology in the oil and gas industry: recent advances and perspectives. Energy and Fuels, 35(23), 19266-19287.
21. Ali, J. A., Kolo, K., Manshad, A. Kh., Mohammadi, A. H. (2018). Recent advances in application of nanotechnology in chemical enhanced oil recovery: effects of nanoparticles on wettability alteration, interfacial tension reduction, and flooding. Egyptian Journal of Petroleum, 27, 1371-1383.
22. Kandiel, Y. E., Attia, G., Metwalli, F. I., Khalaf, R. E. (2025). Nanoparticles in enhanced oil recovery: state of the art review. Journal of Petroleum Exploration and Production Technology, 15(4), 66.
23. Cheraghian, G., Rostami, S., Afrand, M. (2020). Nanotechnology in enhanced oil recovery. Processes, 8(9), 1073.
24. Shamilov, V. M., Babayev, E. R. (2019). Biocidal composition based on copper nanoparticles for the oil industry. SOCAR Proceedings, 2, 46–50.
25. Bera, A., Belhaj, H. (2016). Application of nanotechnology by means of nanoparticles and nanodispersions in oil recovery – A comprehensive review. Journal of Natural Gas Science and Engineering, 34, 1284–1309.
26. Almahfood, M., Bai, B. (2018). The synergistic effects of nanoparticle-surfactant nanofluids in EOR applications. Journal of Petroleum Science and Engineering, 171, 196-210.
27. Astruc, D. (2020). Introduction: nanoparticles in catalysis. Chemical Reviews, 120(2), 461–463.
28. Ismailov, F. S. (2018). Scientific and practical foundations for the development of new methods to enhance well productivity and well workover at mature oil fields. Doctoral Thesis. Baku, Azerbaijan.
29. Suleimanov, B. A., Guseynova, N. I., Rzayeva, S. C., Tulesheva, G. D. (2017). Experience of acidizing injection wells for enhanced oil recovery at the Zhetybai field (Kazakhstan). SPE-189028-MS. In: SPE Annual Caspian Technical Conference and Exhibition, Baku, Azerbaijan, 1-3 November.
30. Suleimanov, B. A., Rzayeva, S. C., Keldibayeva, S. S. (2020). A new microbial enhanced oil recovery (MEOR) method for oil formations containing highly mineralized water. Petroleum Science and Technology, 38(23), 999-1006.
31. Ravera, F., Santini, E., Loglio, G., Ferrari, M. (2006). Effect of nanoparticles on the interfacial properties of liquid/liquid and liquid/air surface layers. The Journal of Physical Chemistry B, 110(39), 19543–19551.
32. Sun, X., Zhang, Y., Chen, G., Gai, Z. (2017). Application of nanoparticles in enhanced oil recovery: a critical review of recent progress. Energies, 10, 345.
33. Worthen, A. J., Tran, V., Cornell, K. A., et al. (2016). Steric stabilization of nanoparticles with grafted low molecular weight ligands in highly concentrated brines including divalent ions. Soft Matter, 12(7), 2025-2039.
34. Mazloom, M. S., Abdolhossein, H. S., Husein, M. M., Behbahani, H. Sh. (2020). Application of nanoparticles for asphaltenes adsorption and oxidation: a critical review of the challenges and recent progress. Fuel, 279(6), 117763.
35. (2008). Advanced Powder Technologies LLC. Coated aluminum nanopowder. Copper nanopowder. Hexanewetted iron nanopowder. Technical Specification TU 1791-003-36280340-2008.
36. Abdullayev, A. I., Shamilov, V. M., Shamilov, F. V., et al. (2024). Metal əsasli nanotozlarin alinmasi üsulu. Azerbaijan Republic Patent I 2025 0132.
37. ALKAN DE-202B. Crude oil demulsifier. Technical specification TU AZ 52411296-01-96. State Registration No. 4146.
38. ALKAN DE-318A. Crude oil demulsifier. Technical specification TU AZ 52411296-02-98.
39. (2018). GOST 2477-2014. Petroleum and petroleum products. Method for determination of water content. Moscow: Standartinform Publishers.
40. (2007). GOST 6709-72. Distilled water. Specifications. Moscow: Standartinform Publishers.
41. (1984). GOST 18499-73. Kerosene for technical purposes. Specifications. Moscow: Standards Publishing House.
42. Jabbarova, K. Sh. (2020). Development and investigation of nano-surfactant systems. Transactions of Azerbaijan Higher Technical Educational Institutions, 22(4), 34–39.
43. Shahbazov, E. K., Jabbarova, K. Sh. (2018). Investigation of surfactant property regulation through nanoeffects. Transactions of Azerbaijan Higher Technical Educational Institutions, 4, 29–38.
44. Almahfood, M., Bai, B., Wei, M., Delshad, M. (2020). Effect of nanoparticle-assisted surfactants on interfacial properties and oil displacement efficiency. Fuel, 278, 118297.

The investigation of the rheological properties and demulsification behavior of oil–water emulsions formed in oil gathering systems is of considerable importance for addressing technological challenges associated with crude oil treatment, dehydration, and transportation. In this study, the rheological behavior of oil–water emulsions containing 0–90 % formation water and the performance of a newly developed demulsifier composition were experimentally evaluated under laboratory conditions. The results demonstrated that the effective viscosity and shear stress of the emulsions are strongly dependent on water content. An increase in the volumetric fraction of water enhanced droplet–droplet interactions, promoted structural strengthening of the system, and increased resistance to flow. Rheological measurements confirmed the non-Newtonian behavior of the investigated emulsions and revealed a significant increase in viscosity with increasing dispersed phase concentration. To intensify the demulsification process, a novel formulation based on polypropylene glycol, polyethylene polyamine, sodium naphthenate, and methanol was developed. Laboratory experiments showed that the proposed composition provided a water separation efficiency of 77–81 % in emulsions containing 60% water. This effect is attributed to the reduction in the stability of the interfacial layer and the acceleration of water droplet coalescence. It was also found that freshly prepared emulsions were demulsified more readily than emulsions stored for five days, while increasing the demulsifier dosage improved separation efficiency only up to an optimum level. The obtained results indicate a clear relationship between the structural-rheological characteristics of emulsions and their demulsification efficiency, providing a scientific basis for improving the technological efficiency and operational reliability of crude oil dehydration processes. 

Keywords: oil–water emulsion; rheological properties; gathering system; demulsifier composition; emulsion breakdown; flowability.

Date submitted: 17.03.2026     Date accepted: 12.06.2026     Date published: 31.07.2026

References

1. Gasimzade, A., Nurullayev, V. (2026). Evaluation of a new composition for enhanced demulsification and deposit control in resinous heavy oil emulsions. Rudarsko-Geološko-Naftni Zbornik, 41(4), Article in Press.
2. Ali, M. F., Alqam, M. H. (2000). The role of asphaltenes, resins and other solids in the stabilization of water in oil emulsions and its effects on oil production in Saudi oil fields. Fuel, 79(11), 1309–1316.
3. Jennings, D. W., Weispfennig, K. (2005). Effects of shear and temperature on wax deposition: Cold finger investigation with a Gulf of Mexico crude oil. Energy & Fuels, 19(4), 1376–1386.
4. Iskandarov, E. Kh. (2024). Study of structural changes in multifaceted gas pipelines. SOCAR Proceedings, 4, 117–122.
5. Ismayilov, Q. Q., Dzhalalov, Q. I., Safarov, N. M. (2021). About one interpretation of the phenomenon of phase inversion in rheological difficult water–oil emulsions. SOCAR Proceedings, 4, 84–89. 
6. Gasimzade, A., Nurullayev, V. (2026). Synergistic composite additives for rheological optimization of high-paraffin crude oil. Periodica Polytechnica Chemical Engineering, 70(2), 357-369.
7. Iskenderov, E. Kh., Ismayilova, F. B., Shukurlu, M. F., Ismayilova, P. S. (2024). Changes in the energy characteristics of pipeline systems considering hydrodynamic loads. SOCAR Proceedings, 2, 105–108.
8. Ismailov, G. G., Iskenderov, E. Kh. (2019). Analysis of compressor station operation based on electrical analogy. SOCAR Proceedings, 3, 81–87.
9. Safarov, N. M. (2022). Development of an innovative method for increasing oil recovery of clay layers. Journal of Engineering Physics and Thermophysics, 95, 1056–1062.
10. Ibrahimov, Kh. M., Tapdiqov, Sh. Z., Kazimov, F. K. (2025). Study of a thermoactive gel-forming system based on biopolymer for water shut-off treatment. SOCAR Proceedings, SI1, 1–9.
11. Mamedov, K. A., Kyazimov, F. K., Seyfiyev, F. G. (2024). Corrosion inhibitor for the protection of oilfield equipment operated in various aggressive environments. Steel in Translation, 54(11), 1130–1133.
12. Safarov, N. M., Ismayilova, F. B., Hajizade, S. G. (2022). Development of a diagnostic method for determining the density of water–oil–sand mixtures. SOCAR Proceedings, 2, 73–77.
13. Mamedov, K. A., Hamidova, N. S. (2021). Prevention of corrosion damage to oilfield equipment with a composition based on technical phosphatides. SOCAR Proceedings, 4, 96–101.
14. Mammadov, K. A., Aliyev, S., Nurullayev, V. (2021). Application of a new corrosion inhibitor for gathering pipelines to improve environmental safety. News of the National Academy of Sciences of the Republic of Kazakhstan. Series Chemistry and Technology, 4(448), 32–39.
15. Mamedov, K. A., Hamidova, N. S., Aliyev, T. S. (2019). Development of a new multifunctional inhibitor for the protection of oilfield equipment. Chemical and Petroleum Engineering, 55(3), 340–346.
16. Seyfiyev, F. G., Mamedov, K. A., Samadov, A. M. (2025). Development of a new composition to increase the operational efficiency of field pipelines. SOCAR Proceedings, 4, 118–121.
17. Mammadov, K. A., Hamidova, N. S. (2020). Development of a multifunctional corrosion inhibitor possessing the properties of a microemulsion. News of the National Academy of Sciences of the Republic of Kazakhstan. Series of Geology and Technical Sciences, 1(439), 64–72.
18. Mammadov, K. A. (2020). Study of the effect of a new combined inhibitor and a permanent magnetic field on corrosion and salt deposition. News of the National Academy of Sciences of the Republic of Kazakhstan. Series Chemistry and Technology, 2(440), 145–152.
19. Manafov, M. R., Shikhieva, F. R., Matiev, K. I., Karimli, V. I. (2022). Study of the effect of asphaltene-resinous compounds on the separation of oil emulsions. Azerbaijan Chemical Journal, 2, 18–27.
20. Seyfiyev, F. G. (2022, August). Study of the formation and prevention of oil emulsions during fluid gathering and treatment of produced hydrocarbons from gas-condensate fields for transportation. In: Proceedings of the 8th International Conference on Control and Optimization with Industrial Applications (COIA), Baku, Azerbaijan.
21. Matiyev, K. I., Agha-zadeh, A. D., Alsafarova, M. E., Akberova, A. F. (2018). Selection of an effective demulsifier for oil–water emulsion breaking and compatibility assessment with a base demulsifier. SOCAR Proceedings, 1, 75–82.
22. Aghazadeh, A. D., Samadov, A. M., Alsafarova, M. E., Akberova, A. F. (2019). Studies on the selection of effective demulsifiers for initial oil treatment and dehydration of hardly breakable water–oil emulsions. SOCAR Proceedings, 1, 75–82.
23. Lekomtsev, A. V., Borisov, M. I., Rozhkova, Y. A., Kang, W. (2023). A comprehensive review of practical approaches to water-in-oil emulsion separation based on magnetic impact. SOCAR Proceedings, SI2, 158–172.
24. Gasimzade, A. V., Ismayilova, A. Q. (2025). Study of the effect of organic substances on the interfacial tension of emulsions. Technique and Technology of Oil and Gas Production, 1, 31–39.
25. Gasimzade, A. V. (2024). Study of a multifunctional composition in the treatment and transportation of heavy oils. Voprosy Khimii i Khimicheskoi Tekhnologii, 4, 25–33.
26. Huseynova, N. I., Safarov, N. M., Safarova, G. N. (2023). Hydrodynamic simulation of the current state of fluid filtration under the impact of water emulsion on an oil reservoir. SOCAR Proceedings, SI1, 87–95.
27. Nurullayev, V. X., Qurbanov, H. R., Gasimzade, A. V. (2023). Effect of asphaltene–resin–paraffin compounds on the temperature-dependent rheological properties of crude oils and emulsions. PAHTEI – Proceedings of Azerbaijan High Technical Educational Institutions, 31(8), 234–243.
28. Nurullayev, V. H., Murvatov, F. T., Gasimzade, A. V. (2022). On the prospects for the development of the Siyazan monocline oil field of the Republic of Azerbaijan. SOCAR Proceedings, SI1, 85–92.
29. Safarov, N. M. (2013). On the study of emulsion formation processes in reservoirs and the possibility of their application for increasing oil recovery factor based on rheotechnology. Oil Industry, 1, 86–89.
30. Dolz, M., Hernández, M. J., Delegido, J. (2008). Creep and recovery experimental investigation of low oil content food emulsions. Food Hydrocolloids, 22(3), 421–427.

This article is devoted to improving the quality of motor fuels. Increasing the depth of oil refining leads to an increase in the yield of secondary gasoline fractions. Coking gasoline is one of these low-quality gasolines. As is known, coking gasoline is characterized by an increased content of unsaturated hydrocarbons, low performance characteristics and a high content of sulfur and resinous compounds. Moreover, such gasolines have a relatively low octane number. In our study, we examined the effect of ultrasonic pretreatment of the feedstock on the hydrotreating process. A mixture of straight-run diesel fuel and heavy fraction of coking gasoline in a ratio of 70:30 was used as raw material. We used a two-layer catalyst system that has proven its effectiveness in previous experiments. The hydrotreating process was carried out under optimal parameters: process temperature of 320 °C, hydrogen pressure of 0.3 MPa, feed volumetric flow rate of 1 h^–1, and hydrogen-containing gas to feed ratio of 350 m³/m³. As a result of the experiments, the sulfur content in coking gasoline was reduced to 0.038% by weight, which is almost five times less than in the original raw material.

Keywords: cavitation; hydrotreating; desulfurization; coking gasoline; straight-run diesel fuel.

Date submitted: 06.05.2025     Date accepted: 12.11.2025     Date published: 30.07.2026

References

1. Garayevа, N. T., Zeynalov, G. A., Hajiyev, А. M., et al. (2024). Application of the United Nations Framework Classification to assessment of the prospective resources of hydrocarbons in Azerbaijan. SOCAR Proceedings, 1, 18-23.
2. Zholbassarova, A. T., Bayamirova, R. Y., Ratov, B. T., et al. (2024). Development of technology for intensification of oil production using emulsion based on natural gasoline and solutions of nitrite compounds. SOCAR Proceedings, 2, 48-55.
3. Gasanov, A. H., Ayyubov, I. H., Aliyev, S. S., Babayev, E. R. (2024). Fuel hydrocarbons based on dicyclopentadiene: A short review. SOCAR Proceedings, 3, 98–106.
4. Speight, J. G. (2014). The chemistry and technology of petroleum. 5th Ed. Boca Raton: CRC Press.
5. Filimonova, A. A., Vlasova, A. Yu., Kamalieva, R. F. (2025). Adsorption methods for purification of petrochemical industrial gas emissions from sulfur compounds using adsorbents from industrial and agricultural waste. A short review. SOCAR Proceedings, 1, 100-108.
6. Ancheyta, J., Speight, J. G. (2007). Hydroprocessing of heavy oils and residua. 1st Ed. Boca Raton: CRC Press.
7. Song, C. (2003) An overview of new approaches to deep desulfurization for ultra-clean gasoline, diesel fuel and jet fuel. Catalysis Today, 86. 211-263.
8. Oripov, S. T., Turaeva, H. T. (2017). Theoretical foundations of adsorption purification of oils. Issues of Science and Education, 3(4), 45-51.
9. Ibragimova, M. D., Seidova, S. A., Alieva, S. G., et al. (2022). Research of the residual content of aromatic hydrocarbons in the composition of diesel fuel after extraction cleaning. SOCAR Proceedings, 3, 101-105.
10. Budukva, S. V., Eletsky, P. M., Zaikina, O. O., et al. (2019). Middle distillates of secondary origin and their processing (review). Petrochemistry, 59(5), 485-501.
11. Saleh, T. A., Al-Hammadi, S. A., Tanimu, A., Alhooshani, K. (2018). Ultra-deep adsorptive desulfurization of fuels on cobalt and molybdenum nanoparticles loaded on activated carbon derived from waste rubber. Journal of Colloid and Interface Science, 513, 779-787.
12. Naranov, E. R., Golubev, O. V., Guseva, A. I., et al. (2017). Hydrotreating of middle distillate fraction on sulfide catalysts containing crystalline porous aluminosilicates. Petrochemistry, 57(6), 773-781.
13. Solodova, N. L., Nurmukhametova, A. R. (2017). Hydrotreating catalysts. Bulletin of the Technological University, 20(10), 53-60.
14. Makhmudova, L. Sh., Akhmadova, H. H., Khadisova, Zh. T., et al. (2017). Production of low-pour point diesel fuels at Russian oil refineries: status and prospects. Russian Chemical Journal, 61(2), 75-97.
15. Kuzhaeva, A. A., Berlinsky, I. V. (2016). Methods of oxidative desulfurization of petroleum products. Problemy Nauki, 9(51), 23-29.
16. Iovik, Yu. A., Krivtsov, E. B., Golovko, A. K. (2018). Features of oxidative desulfurization of vacuum gas oil. Bulletin of Tomsk Polytechnic University. Georesources Engineering, 329(11), 52-60.
17. Leontyeva, A. I., Bryankin, K. V., Rukhov, A. V., Balabaeva, N. N. (2018). Development of composite absorbers for the process of adsorption desulfurization of oil and its refined products. Bulletin of TSTU, 24(4), 663-669.
18. Leontyeva, A. I., Vyzhanov A. V., Balabaeva N. N., et al. (2018). Diesel fuel cleaning. Desulfurization by adsorption method. Neftegaz.RU, 8, 62-69.
19. Yang, H., Jiang, B., Sun, Y., et al. (2017). Heterogeneous oxidative desulfurization of diesel fuel catalyzed by mesoporous polyoxometallate-based polymeric hybrid. Journal of Hazardous Materials, 333, 63-72.
20. Teimouri, A., Mahmoudsalehi, M., Salavati, H. (2018). Catalytic oxidative desulfurization of dibenzothiophene utilizing molybdenum and vanadium oxides supported on MCM-41. International Journal of Hydrogen Energy, 43(31), 14816-14833.
21. Andryushchenko, N. K., Yunusov, S. G., Khalafova, I. A., et al. (2026). Oxidative sulfur refining of gasoline fractions in the presence of hydrogen peroxide on a heterogeneous catalyst. Chemical Problems, 24(1), 85-93.
22. Yulaeva, A. M., Khokhryakov, M. S., Bankovskaya, E. V., et al. (2023). Oxidative desulfurization of petroleum products and comparative evaluation of negative effect against fungi and bacteria. Master`s Journal, 1(07), 1-9.
23. Wan Abdullah, W. N., Wan Abu Bakar, W. A., Ali, R., et al. (2017). Catalytic oxidative desulfurization technology of supported ceria based catalyst: physicochemical and mechanistic studies. Journal of Cleaner Production, 162, 1455-1464.
24. Sikarwar, P., Arun Kumar, U. K., Gosu, V., Subbaramaiah, V. (2018). Catalytic oxidative desulfurization of DBT using green catalyst (Mo/MCM-41) derived from coal fly ash. Journal of Environmental Chemical Engineering, 6(2), 1736-1744.
25. Yunusov, S. G., Andryushchenko, N. K., Mirzoyeva, L. M., Babayeva, Z. B. (2023). Desulfurization of coking gasoline and diesel fraction mixture by alternative methods. PPOR, 24(2), 310-320.
26. Chiblis, N. V. (2020, May). Hydrotreating of light atmospheric gas oil mixed with gasoline. In: XXI International Conference «Chemistry and Chemical Technology in the XXI Century», Moscow.
27. Mullakaev, M. S., Abramov, V. O. (2017, September). Ultrasonic intensification of oil production and refining processes, cleaning of oil-contaminated waters and soils. In: Proceedings of the International Scientific Conference «Ultrasound: Problems, Developments, Prospects».
28. Wu, Zh., Ondruschka, B. (2010). Ultrasound-assisted oxidative desulfurization of liquid fuels and its industrial application. Ultrasonics Sonochemistry, 17(6), 1027-1032.
29. More, N. S., Gogate, P. R. (2019). Intensified approach for desulfurization of simulated fuel containing thiophene based on ultrasonic flow cell and oxidizing agents. Ultrasonics Sonochemistry, 51, 58-68.
30. Nesterenko, A. I., Berlizov, Yu. S. (2008). On the use of the cavitation phenomenon for cracking hydrocarbons. Chemistry and Technology of Fuels and Oils, 4, 41-43.
31. Nurullaev, V. Kh. (2017). Conditions of formation of cavitation zones and their effect on the physicochemical characteristics of oils. Transport and Storage of Petroleum Products and Hydrocarbon Feedstock, 1, 38-42.
32. Efremova, K. D., Pilgunov, V. N. (2016). Cavitation properties of liquids. Science and Education: Scientific Publication of Bauman Moscow State Technical University, 3, 12-36.
33. Aliyeva, A. Z., Kerimova, U. A., Yunusov, S. G., et al. (2024). Ultrasound in catalysis. Chemistry for Sustainable Development, 32(3), 258-263.
34. Aliyeva, A. Z., Karimova, U. A., Yunusov, S. H., et al. (2025). Liquid-phase oxidation of paraffin concentrate of the boiling fraction at 135-360 °C using ultrasonically treated fullerene soot. SOCAR Proceedings, 4, 240-246.
35. Gasimova, Z. A., Abad-zade, H. I., Jafarov, R. P., Abdullaev, E. Sh. (2014). Determination of optimal parameters of the hydrotreating process for a mixture of heavy catalytic cracking gasoline and straight-run diesel fraction. Oil Refining and Petrochemistry, 2, 6-9.
36. Naumova, O. V., Katkov, D. S., Spiridonova, E. V. (2022). New technology for deep oil refining. The Eurasian Scientific Journal, 14(5), 1-8.
37. Mirzoeva, L. M., Ibragimova, M. D., Nagiev, V. A., et al. (2018). Application of ionic liquids for desulfurization of gasoline fractions. Chemistry and Technology of Fuels and Oils, 4, 28-32.
38. Kobotaeva, N. S., Skorokhodova, T. S. (2020). Ionic liquids as extractants for sulfur-containing compounds in diesel fuel. Petrochemistry, 60(4), 476-482.
39. Wang, J., Zhang, L., Sun, Y., et al. (2018) Deep catalytic oxidative desulfurization of fuels by novel Lewis acidic ionic liquids. Fuel Processing Technology, 117, 81-88.
40. Andryushchenko, N. K. (2018). Reducing the content of sulfur compounds in motor gasolines. Azerbaijan National Research University Press, 20(6), 45-50.
41. Ghafforov, T. K., Bazarov, G. R. (2017). Reducing the sulfur content in diesel fuel. Issues of Science and Education, 3(4), 35-36.
42. Fayzullaev, F. S., Omonkulov, O. T., Bazarov, G. R. (2017). Methods for assessing the quality of diesel fuel. Issues of Science and Education, 3(4), 37-38.
43. Yunusov, S. G., Andryushchenko, N. K., Babaeva, Z. B., et al. (2020). Oxidative desulfurization of gasoline fractions of Azerbaijani oils. Azerbaijan Oil Industry, 5, 48-52.
44. Gasimova, Z., Mukhtarova, G., Andrushchenko, N., et al. (2024). Hydrotreatment of diesel fuel involving distillate fractions. Processes of Petrochemistry and Oil Refining, 25(2), 376-389.
45. Abbasov, V., Mukhtarova, G., Jafarova, K., et al. (2024). Catalytic processing methods of heavy oil residues together with shale oils. Processes of Petrochemistry and Oil Refining, 25(2), 507-515.

The article explores the development directions of Azerbaijan’s electric power system, considering the efficient use of alternative energy sources and their impact on the environment. Increasing geopolitical instability, environmental challenges, and growing energy demand are strengthening the importance of energy security and require diversification of generation sources. In this regard,
Azerbaijan is gradually adapting its national energy strategy to international trends by expanding the use of renewable energy sources and strengthening regional cooperation. Special attention is given to the strategic initiative aimed at creating the «Green Energy Corridor» Caspian–Black Sea–Europe, designed for the export of environmentally friendly electricity produced based on the wind potential of the Caspian Sea. This project contributes to the country’s integration into the international energy system and diversifies exports by reducing dependence on traditional oil and gas resources. The study analyzes statistical data on electricity generation in the country, including the growth dynamics of solar, wind, and hydropower production. According to estimates, Azerbaijan possesses significant technical potential for renewable energy both onshore and offshore, creating favorable conditions for large-scale green energy projects. The technological principles of wind, solar, and hydroelectric power plants are also discussed using simplified mathematical models describing their operational mechanisms. Additionally, the relationship between industrial production and economic growth is analyzed, confirming the strategic role of renewable energy development in reducing production costs and enhancing economic competitiveness. Overall, the results indicate substantial potential for sustainable development of the national energy system. 

Keywords: alternative energy sources; environment; electricity generation; renewable energy; hydropower; solar power; wind power.

Date submitted: 06.05.2025     Date accepted: 12.11.2025     Date published: 30.07.2026

References

1. Abdullayev, K. M., Latifov, Y. I., Abdullayeva, G. K. (2005). Energy resources, electricity generation and the environment. Vol. 1. Baku: Zaman-3.
2. Abdullayev, K. M., Mammadov, R. K., Latifov, Y. I. (2007). Energy resources, electricity generation and the environment. Vol. 2. Baku: Zaman-3.
3. Beksultanova, A. I., Dzhankhotova, P. M., Shardan, S. K. (2022). Renewable and alternative energy sources: Green energy. IOP Conference Series: Earth and Environmental Science, 1045(1), 012134.
4. (2021). Order of the President of the Republic of Azerbaijan on approval of «Azerbaijan 2030: National Priorities for Socio-Economic Development». https://president.az/en/articles/view/50474
5. Nuraliyeva, R. N. (2010). Economic and environmental problems of the development of the fuel and energy complex of Azerbaijan. Baku: Azerneshr.
6. Ismayilova, H. G., Shahlarlı, M. (2022). Fuzzy assessment of oil spills into the environment. Reliability: Theory and Applications, 17, Special Issue 4(70), 305–308.
7. Ismayilov, G. G., Ismayilova, H. G., Jabrayilov, R. (2022). Assessment of environmental oil spills and economic-environmental risks. Reliability: Theory and Applications, 17, Special Issue 4(70), 212–217.
8. State Statistical Committee of the Republic of Azerbaijan. Fuel and energy balance statistics. https://www.stat.gov. az/source/balance_fuel/?lang=en
9. Ministry of Energy of the Republic of Azerbaijan. Use of renewable energy sources in Azerbaijan. https://minenergy. gov.az/en/alternativ-ve-berpa-olunan-enerji/azerbaycanda-berpa-olunan-enerji-menbe-lerinden-istifade
10. Verdiyeva, P., Dadashova, J., Bayramov, V., Aliyeva, R. (2025). Green growth strategies for sustainable economic development. Evergreen, 12(1), 387–398.
11. Karimov, K. S., Ismayilov, B. V., Nuraliyeva, R. N. (2024). Some aspects of hydrogen as a future clean energy source. Lecture Notes in Networks and Systems, 1252, 279–284.
12. Mamedova, G. V., Nuraliyeva, R. N., Mammadova, Z., et al. (2024). Investments in Azerbaijan’s electricity
    sector: Equilibrium price and marginal cost function. In book: Applications of mathematics in science and technology (ICMIST-2024). CRC Press.
13. (2023). International Renewable Energy Agency. Renewable capacity statistics of 2023 year. https://www.irena.org/Publications/2023/Mar/Renewable-capacity-statistics-2023
14. Chaudhuri, A., Datta, R., Kumar, M. P., et al. (2022). Energy conversion strategies for wind energy system: Electrical, mechanical and material aspects. Materials, 15(3), 1232.
15. Solarin, S. A., Bello, M. O. (2021). Wind energy and sustainable electricity generation: Evidence from Germany. Environment, Development and Sustainability, 24(7), 9185–9198.
16. Annoni, J., Bay, C., Johnson, K., et al. (2019). Wind direction estimation using SCADA data with consensus-based optimization. Wind Energy Science, 4, 355–368.
17. Coleman, J., Law, K. (2015). Meteorology. Elsevier.
18. Damiani, R., Dana, S., Annoni, J., et al. (2018). Assessment of wind turbine component loads under yaw-offset conditions. Wind Energy Science, 3, 173–189.
19. Sütterlin, B., Siegrist, M. (2017). Public acceptance of renewable energy technologies from an abstract versus concrete perspective and the positive imagery of solar power. Energy Policy, 106, 356–366.
20. Osman, A. I., Chen, L., Yang, M., et al. (2023). Cost, environmental impact, and resilience of renewable energy under a changing climate: A review. Environmental Chemistry Letters, 21, 741–764.
21. Mamedova, G. V., Nuraliyeva, R. N., Mammadova, Z., et al. (2024). Investments in Azerbaijan’s electricity sector: Equilibrium price and marginal cost function. Applications of Mathematics in Science and Technology (ICMIST-2024), 81–87. https://doi.org/10.1201/9781003606659-15.
22. Nuraliyeva, R. N., Mamedova, G. V., Abasova, A. A., et al. (2024). Evaluation of customs-tariff regulation in Azerbaijan’s container transport system and its impact on the environment. In book: Applications of mathematics in science and technology (ICMIST-2024). CRC Press.
23. Killingtveit, A. (2020). Hydroelectric power. Future energy. 3rd Ed. Elsevier.
24. Cassano, S., Sossan, F., Landry, C., Nicolet, C. (2021). Performance assessment of linear models of hydropower plants. In: IEEE PES Innovative Smart Grid Technologies Europe (ISGT Europe), Espoo, Finland.
25. Azerbaijan Renewable Energy Agency under the Ministry of Energy of the Republic of Azerbaijan. https://www.area. gov.az/en.
26. Ngancha, P. B., Numbi, B. P., Kusakana, K. (2024). Optimal potential of cascading the hydro-power energy generation site with a hydrokinetic turbine generation system. Heliyon, 10(20), e39663.
27. Rahman, M. F. A., Kamal, N. A., Abdullah, J. (2025). Unlocking the potential of micro-hydropower in water distribution networks: A systematic review for Malaysia’s sustainable energy future. Discover Sustainability, 6, 56.
28. Ridgill, M., Lewis, M. J., Robins, P. E., et al. (2022). Hydrokinetic energy conversion: A global riverine perspective. Journal of Renewable and Sustainable Energy, 14, 044501.
29. Hunt, J. D., Byers, E., Prenner, R., Freitas, M. A. V. (2018). Dams with head increaser effect: Harnessing potential and kinetic power from rivers with large head and flow variation. Energy Conversion and Management, 157, 549–561.
30. Cherchi, C., Badruzzaman, M., Oppenheimer, J., et al. (2015). Energy and water quality management systems for water utility operations. Journal of Environmental Management, 153, 108–120.
31. Kanakoudis, V., Gonelas, K. (2014). Developing a methodology towards full water cost recovery in urban water pipe networks based on the «user-pays» principle. Procedia Engineering, 70, 907–916.
32. Yadigarov, T. A. (2019). Operations research and solving econometric problems in MS Excel and EViews: Theory and practice. Baku: Elm.
33. Amirnia, G., Kamranzad, B., Mafi, S. (2017). Wind and wave energy potential in the southern Caspian Sea using uncertainty analysis. Energy, 120, 332–345.
34. Mammadov, M. A., Yadigarov, T. A., Safarova, G. N., (2024). An economic and mathematical modeling for risk assessment of innovative activities an enterprise in oil and gas industry. SOCAR Proceedings, 4, 139-146.
35. Huseynova, N. I., Safarov, N. M., Safarova, G. N. (2023). Hydrodynamic simulation of the current state of liquid filtration under water emulsion impact on оil layer. SOCAR Proceedings, SI1, 87-95.
36. Safarova, G. N. (2025). Assessment of synergistic effects in oil and gas industry enterprises through the application of economic and mathematical methods. SOCAR Proceedings, 3, 137-147.
37. Khalilov, N. N., Alsafarova, M. E., Hasanov, X. I. (2026). Comparative analysis of newly proposed and existing reagents for the prevention of salt deposition in oil production. SOCAR Proceedings, SI1, 103-107.
38. Ismayilova, F. B., Ismayilova, H. G., Shahlarli, M. E. (2026). Integrated fuzzy AHP–SAM decision framework for offshore pipeline risk management incorporating economic risk factors. SOCAR Proceedings, SI1, 81-89.
39. Mirgeydarova, A. I., Mammadova, E. G. (2025). Mechanism of strategic management of innovative activity in industry. SOCAR Proceedings, 2, 153-158.