G.V. Nesyn, Dr. Sci. (Chem.), Lead Researcher, NesynGV@niitnn.transneft.ru OOO NII Transneft, Moscow, Russia
The article is devoted to cleaning the oil tanks from the bottom sediments. Brief review of mechanical, physico-chemical, thermal, hydraulic methods, as well as their combinations are given. It is noted that wide-spread method of Diogenes type screw propeller caving of tank bottom sediments is not free from shortcomings and unsuitable to prevent their formation because of high power consumption. In this sense, the jet methods are more economical due to the use of a part of potential energy of the flow in the pipeline upstream the tank, and their hydrodynamic power exceeds the power of the propeller-type mixers.
On top of that flooded jets can get additional possibilities by introducing the high molecular weight oil-soluble polymers into the flow. The compact distance of the flooded nozzle jet becomes longer, moreover the jet assumes «cutting» feature. So, the interaction of the «reinforced» jet and the sediments become so close that a heat is produced. The temperature of outer reservoir surface reached 40 º C up to the height of the sediments. Mechanical energy dissipation of the «reinforced» jet to the thermal one, most probably will result in auto acceleration of the washing-out process due to bottom sediments softening. The paper describes an example when polymer activation of the flooded jets helped to move about 4000 tons of sediments from 2 tanks PBC 20000.
Preventing the sedimentation of crude oil heavy components may be carried out with the innovative Immiscible Layer Technology. The very core of the subject is to pour into the oil of the tank some quantity of heavy immiscible liquid, preferably glycerine. Crude oil and glycerine form two layers divided by oil-glycerine interface. Paraffin, resins and asphaltenes do not penetrate into glycerine layer because of their lower density. To prevent their accumulation at the interface the glycerine must be heated at external heat source. Then thermal convection induces the motion of paraffin, resins and asphaltenes away from the interface. External equipment may include also dehydration device and a filter as well. Immiscible Layer Technology can prolong the interval between the cleanings by several times. The corrosion absence in glycerine — bottom contact can also prolong the life of the tank by several times.
1. Gimaletdinov G.M., Sattarova D.M. Methods for cleaning and preventing accumulation of bottom sediments in the tanks. Neftegazovoye delo = Oil and Gas Business. 2006. pp. 1–12. Available at: http://ogbus.ru/authors/Gimaletdinov/Gimaletdinov_1.pdf (accessed: May 10, 2018). (In Russ.).
2. Branch Regulations OP-23.020.00-KTN-230-14. Tank cleaning from bottom sediments. The procedure of organization and performance of work. Moscow: OAO «AK «Transneft», 2015.
3. Chepur P.V., Tarasenko A.A. Features of the joint work of the tank and means of screw type bottom sediments washout. Available at: http://www.fundamental-research.ru/ru/article/view?id=37290 (accessed: May 10, 2018). (In Russ.).
4. Valiyev M.R. Up-to-date methods for cleaning the cavity of vertical steel tanks from bottom sediments. Available at: www.lib.tpu.ru/fulltext/c/2014/C11/V2/236.pdf (accessed: May 10, 2018). (In Russ.).
5. Bagautdinov N.Ya., Makarenko O.Ya., Mastobayev B.N., Shammazov A.M. Resource-saving technologies and environmental safety on the main oil pipelines. Saint-Petersburg: Izd-vo «Nedra», 2012. pp. 397–405. (In Russ.).
6. Galiakbarova E.V., Bakhtizin R.N., Nadrshin A.S., Galiakbarov V.F. Safe and energy-efficient elimination of sedimentation during storage of oil in the tanks. Neftegazovoye delo = Oil and Gas Business. 2015. Vol. 13. № 4. pp. 142–148. (In Russ.).
7. Isyanov F.T., Korkh L.M., Tarraf A., Rasvetalov V.A. Patent RF. № 2442632. The method for cleaning tanks from oil sludge. Applied: March 12, 2010. Published: February 20, 2012. Bulletin № 5. (In Russ.).
8. Grebnev A.N. Asphalt and resin paraffin deposits and their inhibition by chemical agents. The thesis of the candidate of chemical sciences. Tyumen, 2009. (In Russ.).
9. Goss M.L. Patent US. № 5085710. The method of using aqueous solutions of chemical agents for the recovery of hydrocarbons and minimization of losses in oil tanks. Applied: October 31, 1989. Published: February 4, 1992.
10. Bakhonina E.I. Up-to-date technologies of processing and recovery of hydrocarbon-containing waste. Information 2. Physico-chemical, chemical, biological methods of utilization and neutralization of hydrocarbon-containing waste. Bashkirskiy khimicheskiy zhurnal = Bashkiria Chemical Journal. 2015. № 2. pp. 41–49. (In Russ.).
11. Davis G.B., M.L. Goss, Schoemann P., Tyler S.S. Crude oil tank cleaning process recovers oil, reduces hazardous wastes. Oil and Gas Journal. 1993. 13/XIL. Vol. 91. № 50. pp. 35–39.
12. Galiakbarov V.F., Zubairov S.G., Sidorov G.M., Telyashev G.G., Akhmetov A.F., Galiakbarova E.V., Yakhin B.A., Alekseyev R.A., Gerasimov A.A. Patent RF. № 156526. Unit for mixing liquid in the tanks. Applied: June 17, 2015. Published: November 10, 2015. Bulletin № 31. (In Russ.).
13. Nesyn G.V. Receiving high-molecular additives that increase the throughput of oil pipelines: Thesis. ... Doctor of Chemical Sciences. Kazan: Kazanskiy gosudarstvennyy tekhnologicheskiy universitet, 2007. (In Russ.).
14. Nesyn G., Manzhay V., Shtin I., Malkin A. Toms Effect in Flooded Jets. Proceedings of the 5th European Rheology Conference. Berlin: Springer, 1998. pp. 153–154.
15. Golyanov A.I., Zholobov V.V., Nesyn G.V., Semin S.L., Shiryayev A.M. Reduction of the hydrodynamic resistance in the flow of hydrocarbon liquids in the pipes with anti-turbulent additives. Nauka i tekhnologii truboprovodnogo transporta nefti i nefteproduktov = Science and Technologies of Oil and Oil Products Pipeline Transport. 2012. № 2. pp. 80–87. (In Russ.).
16. Shtertser A.A., Grinberg B.E. Effect of the hydroabrasive jet on the material: hydroabrasive wear. Prikladnaya mekhanika i teoreticheskaya fizika = Applied Mechanics and Theoretical Physics. 2013. Vol. 54. № 3. pp. 191–201. (In Russ.).
17. Kudin A.M., Barenblatt G.I., Kalashnikov V.N. Vlasov S.A., Belokon V.S. On destruction of the metal obstacle by the jet of the diluted polymer solution. Inzhenerno-fizicheskiy zhurnal = Engineering and Physics Journal. 1973. Vol. 25. № 6. pp. 1090–1094. (In Russ.).
18. Lisin Yu.V., Nesyn G.V., Shyryayev A.M., Lukmanov M.R. Industrial technology of anti-turbulent additives. Nauka i tekhnologii truboprovodnogo transporta nefti i nefteproduktov = Science and Technologies of Oil and Oil Products Pipeline Transport. 2013. № 1 (9). pp. 48–57. (In Russ.).
19. Nesyn G.V. Patent RF. № 2637915. Method for preventing the formation of bottom sediments in the tanks for oil storage and / or transportation. Applied: April 18, 2016. Published: December 7, 2017. Bulletin № 34. (In Russ.).
20. Tronov V.P., Sakhabutdinov R.Z., Tronov A.V., Savelyeva I.V., Shireyev A.I. Patent RF. № 2093442. Method of oil and its products storage in the tank. Applied: July 21, 1993. Published: October 20, 1997. (In Russ.).
21. Gushchin V.V., Yakovenko G.V., Kasharaba O.V., Orlov G.I., Koshcheyev V.I., Berlin M.A., Grabovskiy Yu.P. Patent RF. № 2286297. Method of oil storage and the means for its implementation. Applied: May 5, 2005. Published: October 27, 2006. (In Russ.).