Effectiveness of additives for inhibition of wax deposition in oil-gas mixtures

UDK: 665.622.43
DOI: 10.24887/0028-2448-2018-2-85-89
Key words: condensates, oil, n-alkanes, wax deposition, inhibitors, pour point, temperature of crystallization
Authors: I.V. Litvinets (Institute of Petroleum Chemistry, Siberian Branch of RAS, RF, Tomsk), N.V. Yudina (Institute of Petroleum Chemistry, Siberian Branch of RAS, RF, Tomsk), Yu.V. Loskutova (Institute of Petroleum Chemistry, Siberian Branch of RAS, RF, Tomsk), I.V. Prozorova (Institute of Petroleum Chemistry, Siberian Branch of RAS, RF, Tomsk)

The process of deposit formation in a sample of highly paraffinic crude oil, two samples of gas condensates and their mixtures is investigated. The amount of deposit in the oil is observed to increase with decreasing ambient temperature and hence it is significantly higher than the mass fraction of paraffins, asphaltenes, and resins due to the occlusion of liquid hydrocarbon in the crystal lattice cells. Using the method of gas-liquid chromatography, the individual compositions of n-alkanes responsible for the formation of deposits in the samples under study are determined. A monomodal distribution of n-alkanes in oil and gas condensate samples is observed. The deposits isolated fr om the crude oil and gas condensates are characterized by a bimodal molecular mass distribution of n-alkanes and an increased content of high molecular hydrocarbons. The efficiency of additives inhibiting the formation of deposits in the oil sample and its mixtures with condensates is investigated. The experimental K-210 additive is found to exhibit better inhibitor and depressor properties in the highly paraffinic crude oil. An addition of 0.05 % wt. of K-210 into the oil sample allowed reducing the deposition rate by 81-85 %. The inhibiting effect of K-210 however decreases in the oil - gas mixtures.

It is shown that the inhibitory effect of the additives based on poly (alkyl) acrylates depends on the composition of paraffin hydrocarbons and resin components of the oil systems under study. The stages of nucleating seed formation and spontaneous crystallization are determined from the cloud point, spontaneous crystallization temperature, and pour point. A possibility of adjusting the structural phase transition in the cases wh ere the temperature decreases during crystallite nucleation and growth is shown. The decrease in the spontaneous crystallization temperature upon introduction of 0.05% wt. of additives into the oil-gas mixture is negligible and is found to be about 3–5 °C, while the pour point of oil with an additive decreased by 13–17 °C and that of the oil-gas mixtures  by 18–20 °C.


1. Yudina N.V., Loskutova Yu.V., Prozorova I.V. et al.,  Rheological properties and dynamics of the formation of sludge of oil and gas mixtures (In Russ.), Gazovaya promyshlennost' = GAS Industry of Russia, 2014, no. 5, pp. 89–92.

2. Tugunov P.I., Nestatsionarnye rezhimy perekachki neftey i nefteproduktov (Unsteady conditions of pumping oil and petroleum products), Moscow: Nedra Publ., 1984, 222 p.

3. Anufriev R.V., Volkova G.I., Changes of the structural and mechanical parameters of hydrocarbons after high-frequency acoustic action (In Russ.), Khimiya v interesakh ustoychivogo razvitiya = Chemistry for Sustainable Development, 2014, V. 22, no. 3, pp. 307 – 312.

4. Prozorova I.V., Volkova G.I., Yudina N.V. et al., Influence of a composite additive on rheological and energy characteristics of wax and high-wax oils (In Russ.), Neftepererabotka i neftekhimiya, 2014, no. 3, pp. 36–39.

5. Evdokimov I.N., Problemy nesovmestimosti neftey pri ikh smeshenii (Oil incompatibility problems during oil mixing), Moscow: Publ. of Gubkin Russian University of Oil and Gas, 2008, 93 p.

6. Yudina N.V., Loskutova Yu.V., Composition and rheological properties of oil deposits of highly paraffinic crude oil (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2012, no. 2, pp. 69–71.

7. Prozorova I.V., Yudina N.V., Nebogina N.A. et al., Selection of inhibitor and depressor additive for oil of the Verhnechonsky oilfield (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2010, no. 6, pp. 68–70.

8. Pol'skaya N.N., Samoylenko A.Yu., Golovanchikov A.B. et al., Influence thermal and desqueezering processings on rheological properties of oil (In Russ.), Izvestiya Volgogradskogo gosudarstvennogo tekhnicheskogo universiteta, 2012, V. 5, no. 1, pp. 114–118.

9. Litvinets I.V., Prozorova I.V., Effect of inhibitor additives on the composition of paraffin deposits of gas condensate from the Urengoy field (In Russ.), Khimiya v interesakh ustoychivogo razvitiya = Chemistry for Sustainable Development, 2015, no. 3, pp. 309–315.

10. Hammami A., Ratulowski J., Coutinho J.A.P., Cloud points: Can we measure or model them, Petroleum Science and Technology, 2003, V. 21, no. 3, pp. 345–358.

11. Srivastava S.P., Saxena A.K., Tandon R.S. et al., Measurement and prediction of solubility of petroleum waxes in organic solvents, Fuel, 1997, V. 76, no. 7, pp. 625–630.

12. Paso K., Senra M., Yi Y. et al., Paraffin polydispersity facilitates mechanical gelation, Ind. Eng. Chem. Res., 2005, no. 44, pp. 7242–7254.

13. Tumanyan B.P., Nauchnye i prikladnye aspekty teorii neftyanykh dispersnykh sistem (Scientific and applied aspects of the theory of oil disperse systems), Moscow: Tekhnika Publ. 2000, 336 p.

To buy the complete text of article (a format - PDF) or to read the material which is in open access only the authorized visitors of the website can. .

Mobile applications

Read our magazine on mobile devices

Загрузить в Google play

Press Releases