Methods of FTIR spectroscopy, NMR and MALDI mass-spectrometry were used to study asphaltenes, resins and oil of the Varadero oil field (Cuba). We determined the content of macro elements of oil: С = 76.11, H – 9.32, N – 0.56 and S– 8.35 %, the content of metal V and Ni in the oil 0,0103 and 0,0064% , in asphaltene 0,029 and 0.022 % respectively. The most probable molecular masses of resins and asphaltenes were established which amounted to 765 and 929 atomic units respectively. The features of the structural-group composition and molecular characteristics of oil, asphaltenes and resins are revealed. According to the spectral coefficients obtained from the IR-Fourier spectra, oil and resins of the Varadero oilfield have high aliphaticity, branching, condensation, oxidation and sulfur content; in addition, the resins have a relatively high content of carboxyl, sulfoxide and sulfonic groups. Asphaltenes are highly aromatic, aromatic compounds mainly have a condensed structure and are paramagnetic. According to 1H and 13C NMR spectroscopy, the ratio of alkyl group protons and aromatic fragments was found to be 12.6:1. Asphaltenes in oil are unstable, having a high colloidal instability index – 1.24, in the conditions of formation and production are able to stabilize the water-oil emulsion (WNE) and form solid deposits. Rheological method shows that at a temperature of 21 °C there is a structural reorganization of VNE. Temperature dependences in the temperature ranges from 10 to 21 °C and from 21 to 40 °C obey the Arrhenius equation. The activation energy of the viscous flow in the first temperature range is 44.3 kJ/mol, and in the second – 61 kJ/mol.
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