The use of oil soluble catalyst precursors based on transition metals (iron, cobalt, nickel, and copper) was studied in order to improve the efficiency of oil production by steam injection technology. Experiments of steam impact on heavy oil with additives of catalyst precursors (0.2 % by metal) were carried out in an autoclave at temperatures 250 and 300 °C for 6 h and a pressure of 9 MPa corresponding to the reservoir data. To assess the efficiency of catalysts the composition and structure of heavy oil was characterized before and after steam impact by SARA analysis, elemental analysis, gas chromatography-mass spectrometry and MALDI mass spectrometry methods. It is established that the use of catalysts, the active form of which is formed in-situ, provides a reduction of heavy components fraction, as well as reduction of average molecular weight of oil. In addition, the simultaneous usage of catalysts with hydrogen donors can increase the H/C ratio. Nickel-based catalyst was the most suitable among the transition metals studied. Its application together with steam injection allows to reduce the heavy oil viscosity in laboratory conditions. The obtained results show that the use of a cyclic system injection together with aquathermolysis catalysts allows to carry out heavy oil upgrading in reservoir conditions, improve rheological properties of heavy oil and, as a result, increase the current production rate of wells.
References
1. Shah A., Fishwick R., Wood J. et al., A review of novel techniques for heavy oil and bitumen extraction and upgrading, Energy Environ. Sci., 2010, V. 3, pp. 700–714.
2. Tumanyan B.P., Petrukhina N.N., Kayukova G.P. et al., Aquathermolysis of crude oils and natural bitumen: Chemistry, catalysts and prospects for industrial implementation (In Russ.), Uspekhi khimii = Russian Chemical Reviews, 2015, V. 84 (11), pp. 1145– 1175.
3. Maity S.K., Ancheyta J., Marroquın G., Catalytic aquathermolysis used for viscosity reduction of heavy crude oils: A review, Energy & Fuels, 2010, V. 24, pp. 2809–2816.
4. Kayukova G.P., Gubaidullin A.T., Petrov S.M. et al., The changes of asphaltenes structural-phase characteristics in the process of conversion of heavy oil in the hydrothermal catalytic system, Energy Fuels, 2016, V. 30, pp. 773–783.
5. Galukhin A.V., Erokhin A.A., Nurgaliev D.K., Effect of catalytic aquathermolysis on high-molecular-weight components of heavy oil in the Ashal’cha field, Chem. Technol. Fuels Oils, 2015, V. 50, pp. 67–69.
6. Wen S., Zhao Y., Liu Y., S. Hu, A study on catalytic aquathermolysis of heavy crude oil during steam stimulation, SPE 106180-MS, 2007.
7. Chao K., Chen Y., Liu H. et al., Laboratory experiments and field test of a difunctional catalyst for catalytic aquathermolysis of heavy oil, Energy Fuels, 2012, V. 26 (2), pp. 1152–1159.
8. Feoktistov D.A., Sitnov S.A., Vahin A.V. et al., The description of heavy crude oils and the products of their catalytic conversion according to SARA-analysis data, International Journal of Applied Engineering Research, 2015, V. 10, pp. 45007–45014.
9. Vakhin A.V., Morozov V.P., Sitnov S.A. et al., Application of thermal investigation methods in developing heavy-oil production technologies, Chem. Technol. Fuels Oils, 2015, V. 50 (6), pp. 569–578.
10. Sitnov S.A., Petrovnina M.S., Feoktistov D.A. et al., Intensification of thermal steam methods of production of heavy oil using a catalyst based on cobalt (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 11, pp. 106–108.
