Oil vanadylporphyrin complexes were obtained by extraction in the presence of N-N-dimethylformamide. In the chromatographic separation of vanadylporphyrin complexes, four main fractions were obtained from the oils of the oil field “North Buzachi” , where all types of known oil porphyrin structures were identified, dominated by deoxophylloerythroethioporphyrin – types with two absorption maxima of 534 Nm and 573 nm. It was found that the total concentration of vanadylporphyrin complexes registered in the absorption zone of 534 nm and 573 nm is 11 times higher than the concentration of nickelporphyrin complexes characteristic of the absorption zone of 550 nm. The ratio of vanadylporphirins of the etio - and deoxo-phylloerythroethioporphyrin (DPEP) type was 0.11. The results of the research allow us to conclude that the oil of the “North Buzachi” oil and gas district is a promising raw material for obtaining vanadylporphyrin complexes.
 Vinogradova O.K. Oil - 2017: Results, trends, forecasts//Oil and gas vertical. - 2018. №4. -Р.6-12
 B. McKay Rytting, I. D. Singh, Peter K. Kilpatrick, Ultrahigh-Purity Vanadyl Petroporphyrins, : Energy Fuels 2018, 32, 5711−5724
 López L., Lo Mónaco S. Vanadium, nickel and sulfur in crude oils and source rocks and their relationship with biomarkers: Implications for the origin of crude oils in Venezuelan basins // Organic Geochemistry 104 (2017) 53–68
 Jenifer, Annie C., Sharon, Princy, Prakash, Arushi, Sande, Priya C. A review of the unconventional methods used for the demetallization of petroleum fractions over the past decade // Energy Fuel. 2015, 29, 7743-7752.
 Ali, Mohammad Farhat, Abbas, Saeed A review of methods for the demetallization of residual fuel oils // Fuel Process. Technol. 87, 573-584.
 Sorokina T.P., Buluchevskaya L.A., Potapenko O.V., Doronin V.P. Conversion of nickel and vanadium porphyrins under catalytic cracking conditions // Pet Chem 2010;50(1):51–5.
 Luz M.S., Oliveira P.V. Non-chromatographic method for separation and determination of Fe, Ni and V porphyrins in crude oil // Talanta 2019;199:147–54.
 Wang B., Kurian V., Mahapatra N., Martens F., Gupta R. Investigation of corrosion and fouling in syngas cooler tubes // Fuel Process Technol 2016;141:202–209.
 Kohli K., Prajapati R., Maity S.K., Sau M., Garg M.O. Deactivation of hydrotreating catalyst by metals in resin and asphaltene parts of heavy oil and residues // Fuel 2016;175:264–73.
 Rodríguez E., Félix G., Ancheyta J., Trejo F. Modeling of hydrotreating catalyst deactivation for heavy oil hydrocarbons // Fuel 2018;225:118–33.
 Etim U.J., Bai P., Liu X., Subhan F., Ullah R., Yan Z. Vanadium and nickel deposition on FCC catalyst: Influence of residual catalyst acidity on catalytic products // Microporous Mesoporous Mater 2019;273:276–85.
 Jocelyn E. Zuliani, Tomohiro Miyata, Teruyasu Mizoguchi, Jing Feng, Donald W. Kirk, Charles Q. Jia Characterization of vanadium in oil sands fluid petroleum coke using electron microscopy // Fuel 178 (2016) 124–128.
 Maciel S. Luz, Pedro V. Oliveira Non-chromatographic method for separation and determination of Fe, Ni and V porphyrins in crude oil // Talanta 199 (2019) 147–154
 Sugiyama, A.E. Williams-Jones, An approach to determining nickel, vanadium and other metal concentrations in crude oil // Anal. Chim. Acta 1002 (2018) 18–25.
 P.A. Mello, J.S.F. Pereira, M.F. Mesko, J.S. Barin, E.M.M. Flores, Sample preparation methods for subsequent determination of metals and non-metals in crude oil-A review // Anal. Chim. Acta 746 (2012) 15–36
 X. Zhao, C. Xu, Q. Shi, Porphyrins in heavy petroleums: a review, in: Structure and Modelling of Complex Petroleum Mixtures // 168 Springer, Switzerland, 2016, pp. 39–70 (Structure and Bonding Series).
 H.S. Silva, A.C.R. Sodero, J.P. Korb, A. Alfarra, P. Giusti, G. Vallverdu, D. Begue, I. Baraille, B. Bouyssiere, The role of metalloporphyrins on the physical-chemical properties of petroleum fluids // Fuel 188 (2017) 374–381.
 Dechaine G.P., Gray M.R., Chemistry and association of vanadium compounds in heavy oil and bitumen, and implications for their selective removal // Energ. Fuel 24 (2010) 2795–2808.
 G. Caumette, C.P. Lienemann, I. Merdrignac, B. Bouyssiere, R. Lobinski, Fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography-ICP MS and normal phase HPLC-ICP MS // J. Anal. At. Spectrom. 25 (2010) 1123–1129.
 M.F Shostakovsky, O.V. Serebrennikova, R.F. Ivanitskaya, V.I. Titov. Extraction of metal-porphyrin complexes of oil of Western Siberia//Geochemistry. – 1974. № 7.Р. 1100–1103.
 Yakubov M.R., Milordov D.V., Yakubova S.G., D.N. Borisov, Gryaznov P.I., Mironov N.A., Tazeeva E.G. Features of the composition of vanadyl porphyrins in the raw extract of heavy oil asphaltenes with high vanadium content//Oil science and technology, 34 (2), 177–183.
 N.Zh. Mamardashvili, Golubchikov O. A. Spectral properties of porphyrins and their predecessors and derivatives//Usp. chemical., 70:7 (2001), 656–686; Russian Chem. Reviews, 70:7 (2001), 577–606