Skip to main content
SpringerLink
Log in

Dynamic rheological analysis of the gelation behaviour of waxy crude oils

  • Original Contribution
  • Published:
Rheologica Acta Aims and scope Submit manuscript

Abstract

In this work we have characterised the viscoelastic behaviour of paraffin crystals in three different complex crude oils, close to the gelation threshold and after curing the gels under quiescent isothermal conditions, by means of oscillatory shear measurements. An increase in gelation temperature is observed with increasing oil’s molecular weight. The interactions between wax crystals and the formation of the space-filling network of interlocking wax crystals are thus facilitated by the presence of paraffins with higher molecular weight. The apparent gelation time, obtained from isothermal curing experiments, decreases as the curing temperature was decreased, and it is highly temperature-dependent.

The presence and the importance of the ageing of the wax were established under isothermal conditions. It must result from a coarsening of the crystallites presents in the oil and it is, more important, close to the gel point where its full development is very slow taking several days to occur. After ageing the gels, the connective domains or junction zones linking the crystal arrays fail when relatively small strains are applied to the system and the mechanical spectra of the gels reveal an imperfect elastic network, typical rheological characteristics of a particle gel. Despite the compositional differences among the samples, the similarity of their mechanical behaviour is quite remarkable indicating that in all cases the gel-like organisation of the waxy material results from the formation of identical structures in the different oils, which is related not only to the wax content but also to the presence of other material that may reduce the crystallinity of the structure.

The low fractal dimensionality obtained indicates elongated substructures. These results, together with the very high elastic modulus obtained at low volume fractions of crystallised material, are indicative of network structures with high degree of porosity: a lattice of wax crystals with large spaces among them filled by the oil and non-precipitated material.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2A,B
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

References

  • Buscall R, Mills PDA, Goodwin JW, Lawson DW (1988) Scaling behavior of the rheology of aggregate networks formed from colloidal particles. J Chem Soc, Farad Trans I 84:4249–4260

    Google Scholar 

  • Chang C, Boger DV, Nguyen QD (2000) Influence of thermal history on the waxy structure of statically cooled waxy crude oil. SPE J 5:148–157

    Google Scholar 

  • Cordoba AJ, Schall CA (2001) Solvent migration in a paraffin deposit. Fuel 80:1279–1284

    Article  CAS  Google Scholar 

  • Coutinho JAP, Daridon, JL (2001) Low-pressure modeling of wax formation in crude oils. Energy Fuels 15:1454–1460

    Article  CAS  Google Scholar 

  • Coutinho JAP, Pauly J, Daridon JL (2001) A thermodynamic model to predict wax formation in petroleum fluids. Braz J Chem Eng 18:411–422

    CAS  Google Scholar 

  • Coutinho JAP, Lopes da Silva JA, Ferreira A, Soares MR, Daridon JL (2003) Evidence for the aging of wax deposits in crude oils by Ostwald ripening. Petrol Sci Technol 21:381–391

    Article  Google Scholar 

  • Creek JL, Lund HJ, Brill JP, Volk M (1999) Wax deposition in single phase flow. Fluid Phase Equil 158–160:801–811

    Google Scholar 

  • Daridon JL, Pauly J, Coutinho JAP (2001). Solid-liquid-vapor phase boundary of a North Sea waxy crude: measurement and modeling. Energy Fuels 15:730–735

    Article  CAS  Google Scholar 

  • Dirand M, Chevallier V, Provost E, Bouroukba M, Petitjean D (1998) Multicomponent paraffin waxes and petroleum solid deposits: structural and thermodynamic state. Fuel 77:1253–1260

    Article  CAS  Google Scholar 

  • Kané M, Djabourov M, Volle J-L, Lechaire J-P, Frebourg G (2003) Morphology of paraffin crystals in waxy crude oils cooled in quiescent conditions and under flow. Fuel 82:127–135

    Article  Google Scholar 

  • Lin YG, Mallin DT, Chien JCW, Winter HH (1991) Dynamical mechanical measurement of crystallization induced gelation in thermoplastic elastomeric poly(propylene). Macromolecules 24:850–854

    CAS  Google Scholar 

  • Lopes da Silva JA, Gonçalves MP, Rao MA (1995) Kinetics and thermal behaviour of the structure formation process in HMP/sucrose gelation. Int J Biol Macromol 17:25–32

    Article  PubMed  Google Scholar 

  • Lopes da Silva JA, Gonçalves MP, Doublier JL, Axelos MA (1996) Effect of galactomannans on the viscoelastic behaviour of pectin/calcium networks. Polym Gels Networks 4:65–83

    Article  Google Scholar 

  • Musser BJ, Kilpatrick PK (1998) Molecular characterization of wax isolated from a variety of crude oils. Energy Fuels 12:715–725

    Article  CAS  Google Scholar 

  • Narine SS, Marangoni AG (1999) Fractal nature of fat crystal networks. Phys Rev E59:1908–1920

    Google Scholar 

  • Rønningsen HP (1992) Rheological behaviour of gelled, waxy North Sea crude oils. J Petrol Sci Eng 7:177–213

    Article  Google Scholar 

  • Scanlan JC, Winter HH (1991) Composition dependence of the viscoelasticity of end-linking poly(dimethylsiloxane) at the gel point. Macromolecules 24:47–54

    CAS  Google Scholar 

  • Shih WH, Shih WY, Kim SI, Liu J, Aksay IA (1990) Scaling behavior of the elastic properties of colloidal gels. Phys Rev A 42:4772–4779

    Article  CAS  PubMed  Google Scholar 

  • Singh P, Fogler HS, Nagarajan N (1999) Prediction of the wax content of the incipient wax-oil gel in a pipeline: an application of the controlled-stress rheometer. J Rheol 43:1437–1459

    Article  CAS  Google Scholar 

  • Singh P, Venkatesan R, Fogler HS, Nagarajan N (2000) Formation and aging of incipient thin film wax-oil gels. AIChE J 46:1059–1074

    Article  CAS  Google Scholar 

  • Singh P, Youyen A, Fogler HS (2001) Existence of a critical carbon number in the aging of a wax-oil gel. AIChE J 47:2111–2124

    Article  CAS  Google Scholar 

  • te Nijenhuis K (1997) Thermoreversible networks: viscoelastic properties and structure of gels. Adv Polym Sci 130. Springer, Berlin Heidelberg New York

    Google Scholar 

  • te Nijenhuis K, Winter HH (1989) Mechanical properties at the gel point of a crystallizing poly(vinyl chloride) solution. Macromolecules 22:411–414

    Google Scholar 

  • Venkatesan R, Ostlund JA, Chawla H, Wattana P, Nyden M, Fogler HS (2003). The effect of asphaltenes on the gelation of waxy oils. Energy Fuels 17:1630–1640

    Article  CAS  Google Scholar 

  • Wardhaugh LT, Boger DV (1991) The measurement and description of the yielding behavior of waxy crude oil. J Rheol 35:1121–1156

    Article  CAS  Google Scholar 

  • Winter HH (1987) Can the gel point of a cross-linking polymer be detected by the G′-G″ crossover? Polym Eng Sci 27:1698–1702

    CAS  Google Scholar 

  • Winter HH, Chambon F (1986) Analysis of linear viscoelasticity of a crosslinking polymer at the gel point. J Rheol 30:367–382

    Article  CAS  Google Scholar 

  • Wu H, Morbidelli M (2001) A model relating structure of colloidal gels to their elastic properties. Langmuir 17:1030–1036

    Article  CAS  Google Scholar 

  • Wu CH, Wang KS, Shuler PJ, Tang Y, Creek JL, Carlson RM, Cheung S (2002) Measurement of wax deposition in paraffin solutions. AIChE J 48:2107–2110

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal

    José A. Lopes da Silva

  2. CICECO, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal

    João A. P. Coutinho

Authors
  1. José A. Lopes da Silva
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. João A. P. Coutinho
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to José A. Lopes da Silva.

Rights and permissions

Reprints and permissions

About this article

Cite this article

da Silva, J.A.L., Coutinho, J.A.P. Dynamic rheological analysis of the gelation behaviour of waxy crude oils. Rheol Acta 43, 433–441 (2004). https://doi.org/10.1007/s00397-004-0367-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00397-004-0367-6

Keywords

Search

Navigation